Thermostat replacement with lower temp opening setting

[tomj76]

I feel your pain searcherr. It could be something minor, such as air, which has already been mentioned. Wait for the system to cool down. Check the coolant reservoir again after it cools. It should be down noticeably. If not, then it might have been too full to begin with.

Once it's cold, remove the pressure cap and check the coolant level in the radiator. It should be very close to the top. If not, then there was either air in the system, or the coolant boiled.

Did you hear any noises from the engine indicating the coolant was boiling? If you have a severe over heat and coolant is in the system, then it has to boil. In normal situations, the engine can't get any hotter than the coolant. Therefore, for the engine to go hotter than ~280F, any coolant in that part of the engine must boil.

Did you notice the temperature gauge before you stopped? How long were you stopped? If you idled for very long, it's normal for the coolant temperature to rise 20-40 F before the fan relay is turned on. Once the fan is on it will run until the temperature drops back down, unless as mentioned, the AC is also on. I'm not totally sure of this, but I think the fan on my '96 cycles even with the A/C on, but it's related to both requirements, engine temperature and need for cooling in the A/C condenser.

Let's hope that it's something simple.

[uzzo2]

i would let the engine cool completely (overnight) and then crank it up and take the cap off the radiator and let it idle to watch for flow through the radiator. if it's not flowing you either have defective water pump or thermostat the latter being the most common. also something to check is the tranny fluid you say you have a cooler but is it interlinked with the radiator, if the fluid is getting hot from the towing you're doing that could drive the coolant temp up. check the tranny fluid and make sure it isn't burnt.

[searcherrr]

Before continuuing know that I've now driven back home. My trip is cancelled till further notice. Read on.

Answering questions:

There was no mention of debris found in the cooling system.

Oil looked fine, but I will check again in the morning after its sat.

Coolant is new as of a couple days ago and was not boiling as I'd cut it off as soon as it was nearing H. There were slow small bubbles in 1 stream of bubbles going up through the reservoir though. No boiling noises, no hissing, no sounds.

Heater has always worked every time in every warm condition. Dunno about a rear heater. I used the heater every time on this trip when it was overheating.

Coolant IS interlinked with the tranny cooler. I have not checked the tranny oil in a few weeks, but when I did it was topped off. What would I be checking it for though? Debris and level?

I watched temperature gauge the entire time after 10/24/07 service and it acted as described below.

After service finished on 10/24/07 (pressure tests, water pump replace, radiator replace, 180 F thermostat replace thats 10 F lower than OEM tstat) the odd issue was only apparent after driving in excess of 5 to 10 miles. A quick drive of 1 to 2 miles around town and a quick 1 mile stretch from exit to exit on the interstate wasn't enough to reproduce the issue. The issue is that the temperature was staying at the "L" or grazing the "A" on the gauge the entire time AND THEN after traveling 20 miles on the interstate with the 3000lb payload I stopped to check the tire pressure - IMMEDIATELY following me putting the van in PARK I got out to check the tires and IMMEDIATELY within a minute the radiator cooling fans both kicked on HIGH. Knowing this was not usual and i'd just had it serviced I checked temperature gauge and it was at H or very close to it. I immediately shut off the van. Coolant temp sensor(s) ruled out because the coolant itself was at the TOP of the reservoir nearing the cap. Very disturbed now after spending $1002 to get all this crap fixed and after having spent $700 a couple weeks prior chasing engine computer, mass air flow sensor, IAC motor, and throttle body issues. After I let it cool I got back on the road and immediately it STAYED cool... but even COOLER than the "L" - IT DID NOT REACH THE RANGE OF "NORMAL" TEMP DEFINED BY THE BRACKETS ON THE GAUGE UNTIL ABOUT 15 MILES DOWN THE ROAD BACK TO FORD and even then it was at the bottom bracket and not even touching the "L" - HAVE I FUCKING SCREWED MYSELF PUTTING IN THE 180 F THERMOSTAT???? IT JUST DOES NOT SEEM LIKE IT... BUT MAYBE I F'D MYSELF OVER WITH THAT

IE: IF THE ENGINE NEVER REACHES OPERATING TEMP IT WILL ALWAYS RUN RICH, BUT BY THE TIME THE NEW THERMOSTAT WAS IN THE VAN HAD ONLY BEEN RUN 25 MILES AT MOST.... COULD RUNNING 25 MILES RICH CLOG AND MELT A CONVERTER?????? I will say why I am asking that further down.

What I want to note: The shop said when I left on 10/24/07 the day before that they'd never seen such a smooth running Windstar and that it seemed like their repairs were going to resolve the issue and that the engine was going to be ok. ---- I brought it back to them in the same smooth running manner as there were no odd sounds, no weird shifting, no knocking, no loss of power (in fact felt stronger), no squeaking of the pulley, .. just sounded like a new engine as i started back on my trip and also back to Ford........ THEN Ford's tech revs the sh!T out of it in the garage and in excess of RPMs which you'd experience in normal driving even on the interstate from 60 - 70mph. They were racing it from 3 to 4 rpms for LONG periods to reproduce the overheating. It was running fine until after they messed with it. They could not find anything wrong with it and then several minutes later after excessively revving it constantly they came and told me now that it was missing on Cylinder 3 and when I got in it to leave from Ford again later on it was running like absolute CRAP. The CEL came on as I pulled out of the parking lot of Ford. IF YOU ASK ME THEY BROKE MY ENGINE IN THEIR TESTS.

The Service Manager who I seemingly got to know well while there and possibly developed a friendship with as it seemed (discussed life, family, girlfriend, the trip, gave me relationship advice and he even met my family when they came up to save me) offered to follow me home part of the way cause they felt like it would make it home as long as I was not towing my trailer. This was above and beyond any courtesy service I've ever experienced at any auto shop and was consistent with how they treated me from even before they'd started their initial repairs as they bussed me around to get parts to and from my hotel and even dropped me off places to eat breakfast/lunch. They have my trailer locked up in a secure gated area at their dealership. I drove the van HOME 88 miles in the CRAPPY missing CONDITION I mentioned with the CEL on. The engine sounds horrible now (as if the pistons are gonna burst out and whenever it made that noise I'd back off the accel), but it was not doing ANY of this until AFTER I came out of Ford's garage for the 2nd time on today. In my opinion the tech should've went and drove the van to reproduce the problem not revved it in the garage.

Thinking out of the box like the ASE certified Techs are supposed to do when looking at an odd problems such as this one I thought to check underneath my van as soon as I got home for a CLOGGED CAT which you see by noticing it GLOWING RED. GUESS WHAT I SAW??? A GLOWING RED CATALYTIC CONVERTER - BY NOW I'D DRIVEN THE VAN THE 25 MILES STATED EARLIER from service on 10/24/07 + 88 MILES TO GET IT HOME today 10/25/07.

Now SOMEONE HELP ME ...... ARM me with INFORMATION before I call Ford tomorrow. Would the CAT CLOG after just 113 miles running RICH from a 180 F thermostat???? OR IS IT MORE LIKELY THE CAT WAS CLOGGED FOR QUITE SOME TIME CAUSING ROUGH STARTS AND ROUGH IDLE AND EVENTUALLY WEARING DOWN THE COOLING SYSTEM????

ALSO - IF THE CAT IS GLOWING RED AT ALL AT ANY TIME DOESN'T THIS MEAN ITS CLOGGED?

[wiswind]

I am praying that your vehicle is just "burping" air that is trapped in the cooling system.
I have had this happen with several vehicles.....including my windstar.
It can take a bit of time for this to happen.
You are wise to return to the shop that did the work to have them check it out.

I do not think that the 180 degree thermostat will cause your cat's to become blocked......and certainly not in that amount of time.
I read where the lower temperature can cause higher Nitrous Oxide emission, but I do not know this for certain.

If you decide to change the thermostat later.....I have pictures posted from when I did mine, and yours should be just like it.

The heater check that phil mentions is a great thing......as you have to have coolant flow to get heat.

OK.....I missed page 2 of the thread.....so I shall add this edit.
I wonder if the glowing cat is from fuel from the misfire.
You mention "A glowing cat...", Do you have 2 catalytic converters like the 96 and newer?.
Now.....cylinder #3 is on the back bank of cylinders.......so if that catalytic converter was glowing, and not the converter for the front bank of cylinders, then the misfire may be caused by a ignition problem.....like no spark to cylinder #3.
Causes for this could be spark plug, spark plug wire, or coil pack.

Raw gasoline going into a catalytic converter will cause what you saw....and sadly, can ruin a catalytic converter.


I am still going to stick with the 180 degree thermostat not causing this problem.

[phil-l]

searcherrr -

Wow - You take the prize for "toughest week".

I doubt a cooler thermostat would cause problems like this so quickly. C'mon: The engine is running cold (i.e., open loop mode) for a short period each time it's started it in the morning.

After some quick googling... I wonder if an underlying culprit might be a leaking fuel injector. Overly rich running would explain the catalytic converter. I'm not sure how well this theory ties into the engine overheating; I simply don't have much experience on this particular topic.

I agree a tech should have ridden with you for more than a few miles. Revving a stationary engine doesn't replicate everything the van sees when running on the road under load. Plus I just *hate* revving an engine that's not under load; it doesn't sound right and no engine seems to like it.

[tomj76]

A vacuum guage test should show if the exhaust is clogged.

The catalytic converter "burns" the car's NOx emissions. I'm with wiswind, that you've probably got a rich condition. If a lot of fuel gets in it (i.e. running rich), it can ruin it, as the fuel will burn in the converter. A scan tool should identify that one for you. As he mentioned, check to see if the converter that is hot is the 'rear' one.

If all that's making sense, make sure the plug wires are properly connected, both on the plug and on the coil. Each coil runs two plugs in series, one on each bank of the engine, so if the circuit is not continuous through both plugs, or a coil is bad, then neither plug 'should' fire. However, high voltage has nasty habit of finding a path to complete the circuit, so the other cylinder could still be getting spark even if a wire is completely disconnected.

Also, that rev test was really dumb. A engine that's not doing any work has hardly any heat load on it. If you want an engine to get hot fast, then make it pull something. Since you have a cooling problem, they needed to make the engine do some work to make it hot. Spinning the crankshaft real fast, while sounding like the engine is working, is not going to push a car's cooling system at all.

[searcherrr]

Originally Posted by wiswind

I am praying that your vehicle is just "burping" air that is trapped in the cooling system.
I have had this happen with several vehicles.....including my windstar.
It can take a bit of time for this to happen.
You are wise to return to the shop that did the work to have them check it out.

I do not think that the 180 degree thermostat will cause your cat's to become blocked......and certainly not in that amount of time.
I read where the lower temperature can cause higher Nitrous Oxide emission, but I do not know this for certain.

If you decide to change the thermostat later.....I have pictures posted from when I did mine, and yours should be just like it.

The heater check that phil mentions is a great thing......as you have to have coolant flow to get heat.

OK.....I missed page 2 of the thread.....so I shall add this edit.
I wonder if the glowing cat is from fuel from the misfire.
You mention "A glowing cat...", Do you have 2 catalytic converters like the 96 and newer?.
Now.....cylinder #3 is on the back bank of cylinders.......so if that catalytic converter was glowing, and not the converter for the front bank of cylinders, then the misfire may be caused by a ignition problem.....like no spark to cylinder #3.
Causes for this could be spark plug, spark plug wire, or coil pack.

Raw gasoline going into a catalytic converter will cause what you saw....and sadly, can ruin a catalytic converter.


I am still going to stick with the 180 degree thermostat not causing this problem.

Jeeeeeezus...... this just gets more and more complicated. I thought I only had 1 main cat. From what I recall from tonight it was just at the position that would be right behind the engine.... just behind the front wheels if looking from the rear of the front wheels inward towards the center.

The Plugs and Wires in my van have been replaced within the past 2 years though the coil pack is still probably the original. The guys at the Ford place are telling me they thought it was a head gasket issue though there are no LEAKS outside the engine and from what I can tell no coolant in the oil or vice versa though I will look again and should mention the coolant did not look clean in the coolant reservoir..... but at the same damn time it could be that the damn reservoir is just FUNKY !!! aaaaaaaaaaaaaaaaaaahhhhhhhhhhhhhhhhhhhhhhhhhhhhhhh hhhhh!!!!!!

[searcherrr]

Originally Posted by tomj76

A vacuum guage test should show if the exhaust is clogged.

The catalytic converter "burns" the car's NOx emissions. I'm with wiswind, that you've probably got a rich condition. If a lot of fuel gets in it (i.e. running rich), it can ruin it, as the fuel will burn in the converter. A scan tool should identify that one for you. As he mentioned, check to see if the converter that is hot is the 'rear' one.

If all that's making sense, make sure the plug wires are properly connected, both on the plug and on the coil. Each coil runs two plugs in series, one on each bank of the engine, so if the circuit is not continuous through both plugs, or a coil is bad, then neither plug 'should' fire. However, high voltage has nasty habit of finding a path to complete the circuit, so the other cylinder could still be getting spark even if a wire is completely disconnected.

Also, that rev test was really dumb. A engine that's not doing any work has hardly any heat load on it. If you want an engine to get hot fast, then make it pull something. Since you have a cooling problem, they needed to make the engine do some work to make it hot. Spinning the crankshaft real fast, while sounding like the engine is working, is not going to push a car's cooling system at all.

I'm glad you and Phil agree the rev test was dumb. I've read about pressure testing the cat.... drill a hole in it, insert tube, attach gauge.... if 4 psi or above then its a clogged cat (thats what I read anyway).

I am so spent/tired tonight. I am "breathing" this problem wanting tomorrow to be here so I can finally get this over with. This is an absolute nightmare and I am usually not one to let even heavy stuff get to me. It has been too much a combination of mental and physical effort to meet with failure is just killing me. I need to talk to the Ford place (now 90 miles away from me) before the end of the week/tomorrow..... though I have to be careful cause they are holding my trailer for me.... but I am quite certain if the engine does need to be replaced that their tech most certainly screwed it up when I brought it back today during his high rev long duration tests. I am sorry now I even brought it over there the 2nd time. I should've went somewhere else and gotten a completely new opinion from scratch..... but HOW WOULD I HAVE KNOWN to... UGGGGGGGHhh... I just hope it is as simple as a coil, a plug, or a wire.... I did notice that when all that stuff spewed everywhere that the water pump and tstat are very close to the coils.... maybe something got on something it shouldn't have.... or if I am running rich maybe the plugs are foul even though I replaced them in the past few years. There was really NO cause for them as I saw it to say there was a bad head gasket or warped head(s) cause again it was running as smooth as NEW. To me it was a guess because they did not know what else to say it was and said the only way i was gonna know would be to take apart the engine. I want to wish the engine is still ok, but it really was shaking badly and making bad bad sounds on the way home again as if it cylinders were gonna pop out of the manifold. When you have 1 cylinder missing can it be THAT bad?

[searcherrr]

I don't suppose anyone knows anyone in Southern Louisiana that is a big gear head (or a group of people) that would enjoy helping someone else install an engine huh? I know on the 3S platform there's a lot of those guys that help each other, but for a Windstar I'm not sure who would want to deal with it. If I can get an engine shipped I would need to save on the labor or else I'm gonna be flat broke. This has really screwed up my life right now and not in the usual way that people say cause its a financial burden, but because it is keeping me from moving to live with my gf and start my new life. The problem is I need someone who has engine lifting equipment and perhaps has done 1 or 2 engine swaps before. Though again I am just not wanting it to be the engine and I'm still leaning towards Ford GUESSING and if it is the engine they definitely screwed it up. I don't just want to blame them for the sake of it.... I just can't stress enough how well it was running before that Tech revved the hell outta it.

[uzzo2]

since the cel light is on you need to deal with that issue. either buy yourself a code scanner or bring it to autozone and they will check it for you for free. you need to see why the cel is on

[BlueCaprice]

Sorry to hear about all your rotten luck. I'm having some pretty bad luck with my Windstar also.

Lemme share with you a thought I had. You said you ruled out the Coolant Temperature Sensor earlier because you knew the van was really overheating and not just misreporting the temp, but, I thought there were two cts's, one for the gauge, and one for engine management. You also said when you stopped on the side of the road to check the tires, you heard the fans speed up, immediately went into the van, and the temp was at the H. Now I would think those fans would speed up way before the vehicle was that hot. What if the CTS for engine management was going bad, and just not reporting the temp right? For example, lets say your fans turn on when your engine reaches 210 degrees. Now if your CTS isn't reporting the right temperature, lets say its reporting 60 degrees too low, then when your computer thinks the engine is at 210 and it's time to run the cooling fans, the engine would really be running at 270 degree's, already overheating. Since the other CTS that operates the dash gauge is probably good, the gauge itself would be reading the correct temperature.

Now as far as the cats glowing red, if your themostat is opening at 180 degrees, and the computer thinks the engine is still at 120, I'd think that would cause you to be running rich, possibly explaining the glowing cats.

Anyway, good luck, and be carefull with that tire pressure also. I once accidently filled up the tires in my Windstar to 38 psi due to a faulty pressure gauge and didn't discover it till I got on the highway and started approaching 75mph. Boy was that scary!

[searcherrr]

Originally Posted by BlueCaprice

Sorry to hear about all your rotten luck. I'm having some pretty bad luck with my Windstar also.

Lemme share with you a thought I had. You said you ruled out the Coolant Temperature Sensor earlier because you knew the van was really overheating and not just misreporting the temp, but, I thought there were two cts's, one for the gauge, and one for engine management. You also said when you stopped on the side of the road to check the tires, you heard the fans speed up, immediately went into the van, and the temp was at the H. Now I would think those fans would speed up way before the vehicle was that hot. What if the CTS for engine management was going bad, and just not reporting the temp right? For example, lets say your fans turn on when your engine reaches 210 degrees. Now if your CTS isn't reporting the right temperature, lets say its reporting 60 degrees too low, then when your computer thinks the engine is at 210 and it's time to run the cooling fans, the engine would really be running at 270 degree's, already overheating. Since the other CTS that operates the dash gauge is probably good, the gauge itself would be reading the correct temperature.

Now as far as the cats glowing red, if your themostat is opening at 180 degrees, and the computer thinks the engine is still at 120, I'd think that would cause you to be running rich, possibly explaining the glowing cats.

Anyway, good luck, and be carefull with that tire pressure also. I once accidently filled up the tires in my Windstar to 38 psi due to a faulty pressure gauge and didn't discover it till I got on the highway and started approaching 75mph. Boy was that scary!

You WOULD THINK UNDER TYPICAL OVERHEATING CONDITIONS THAT THE FANS WOULD SPIN UP A LONG TIME BACK.... BUT WHAT YA'LL MIGHT BE MISSING HERE IS THAT THE TEMP GAUGE JUMPS UP LIKE A KID SPRINGING OUTTA BED FOR SOME CHOCOLATE "AS SOON AS I STOP". IE: DRIVING THE TEMP IS FINE AND POSSIBLY EVEN TOO COOL THEN AS SOON AS I STOP WITHIN A MATTER OF SECONDS THE GAUGE JUMPS UP (WITHIN JUST 1 TO 3 OR 4 SECONDS) TO ABOVE MID TO "H" RANGE. This is DIRECTLY consistent with the cat being clogged and I don't need a pressure test to tell me this cause I've had the whole coolant system replaced and nothing else makes sense except when I saw the glowing cat. IE: As soon as I'd stop the van WIND would stop flowing through and around the system thus IMMEDIATELY allowing EXTREME temperature from the CAT to BUILD UPWARD to the rest of the engine and its so HOT that it does so in RECORD TIME. I agree a rich condition would bring that on, but the van also has 157,000 miles on it..... perhaps it was just the CAT'S TIME TO GO !!??!!? NOW as far as the GAUGE CTS goes when I drove it ALL THE WAY BACK HOME the 88 miles the temperature gauge REMAINED ON "COLD" in the BLUE the entire time I drove back and the very 1st moment it climbed upward was as soon as I got off the interstate. Otherwise running on the interstate I was either using the heater the whole time or the vent and it was about 50F cold outside the entire trip back too. Now if the gauge CTS was actually bad you would THINK it wouldn't work right in any predictable/stable fashion...... yet as soon as I come to 1st stop after over a 10 mile drive the gauge immediately reports mid to H range temps and the coolant rises to the top of the reservoir and the CAT glows red. FROM VISUAL inspection this seems to me to be a CTS operating properly YET it probably wouldn't hurt to have BOTH CTS' tested anyway.

I'm sorry BlueCaprice to hear you are having trouble with yours too. I really love this van and what its done for me and how it drives the majority of the time and like I always say it is usually a human that ends up screwing up a machine. I try to live by the rule of thumb to never let any shops TOUCH my vehicles due to this very same kind of bullshit where the guy is revving the engine to 4000 RPMs which eventually killed it. I mean I can attain 70mph without even being in 3000 RPMs and the occassional lurch forward going up a hill MIGHT put me at 3200 - 3500 RPMs and then it immeidately drops back down after gear shift..... not SUSTAINED 3500 - 4000 RPMs like that Tech did in the Ford shop.

EDIT: I am assuming the CEL will report Cylinder 3 misfire as Ford told me though I would like to see the codes myself. I will find out today as soon as some places open up. My current plan is to bring it to my trusted shop here in my hometown for some thoughts/advice after explaining to them the situation and learning the codes being thrown and then calling Ford back and pretty much explaining IN A CALM NICE WAY that I paid them $708 to KNOW THESE THINGS and that on 2nd visit to their shop I brought them a smooth running non-misfiring vehicle and when I left that wasn't the case. As far as I'm concerned they owe me a resolution as their wonder tech ruined it.

[searcherrr]

Ok. I just went and did my own little inspection this morning before i'm about to bring it over to Autzone for reading codes and then to my trusted shop.

1. I let the van run idle for maybe 1 minute (didn't take the cap off while running cause I forgot thats uzzo2 said to do; I'll go do that in a minute or later when I'm at autozone.. I just don't want coolant to explode onto me) and then popped the cap off and the fluid is NOT at the top of the radiator fill hole nor is it above the uppermost radiator coolant coils or passages from what I could see with a flashlight down in the fill hole cause I could see the innards of the radiator without fluid covering it through that fill hole. The coolant reservoir (after being stone cold overnight) is still FULL (before and after start, but again I only ran it for 1 minute) about 5 or 6 inches ABOVE the FULL COLD LINE. TOO MUCH FLUID or is the FLOW not happening as uzzo2 said??? I only handed the Ford shop 2 gallons of Prestone antifreeze.... could this have been too much?

2. The cat I saw glowing was the REAR bank cat. Lets get something straight here..... the cats coming right off the front and rear banks..... ARE those effectively PRE-CATS??? Is the MAIN CAT that huge rectangular box looking thing at the center of the van???? At the time I saw the rear bank cat glowing keep in mind I did not know it was a REAR bank cat as I thought it was the 1 and only MAIN CAT so I did not look for other areas of glowing.... however if they were glowing you would think I would've noticed it as it was dark outside when I got home and I wasn't surrounded by any other ambient light.

3. I cannot reach the rear bank plug wires without jacking the van up and trying to snake in there. I'm too fed up and too fat and too unsure of the jacks to try it. I did however pull the plug wires at the coils for the rear bank only and inspected the plugs and the inner coils with a mirror and the coils looked shiney n new and clean free of marks or debris. I am unsure though about the plug wire I saw as I am not sure if I saw a crack in the metal tip of the plug or if that was a scratch on it. At first glance it appeared as though it were a crack though I don't even know if this would harm anything as there is enough surrounding metal to conduct electricity and all plugs snapped in snug and secure.

4. At this point I think it best to return the vehicle to as much OEM state as I can. I think I'm going to purchase Motorcraft thermostat for my van specifically at Ford in my hometown, swap it in, and see what happens.

Any help you guys may be able to give me this morning before I go out to pursue this problem is greatly appreciated. You guys are great.

[phil-l]

Regarding the rear spark plugs: I did the snake-from-underneath thing once. Just once.

But not again: I removed the cowl (the plastic assembly between the hood and the bottom of the windshield) to replace my struts - and was surprised at just how easy it is. Yes, you need to remove the windshield wipers and some other miscellaneous hardware. And the underlying assembly is kind of big and bulky - but it makes getting to the rear spark plugs far easier than any other approach.

The entirety of this problem is reaching the limits of my expertise. I get the nagging feeling there's some underlying issue that's been missed, or hasn't been addressed properly yet. But I can't quite see what it is.

I'd spend some time with your trusted shop, documenting exactly what happened each step of the way. Yes, being CALM will help everyone do a better job and get to the core of the issue. Hopefully, they'll be able to get a clear picture of what's really happening.

Let us know what you learn!

[searcherrr]

I have found a great overheating guide here:

http://www.tegger.com/hondafaq/overheating/index.html

Though its for Honda's I'm pretty sure all coolant systems on consumer vehicles work the same. According to that guide what I experienced on the road coming back home and before I brought it to Ford the 2nd time are symptoms of 1 of the following (bold red what I've seen on my van; bold blue questionable):

Bad Radiator Cap - (pasted from that link):

1. The main seal is the one that seals the cap against the top of the filler neck. Just a rubber gasket that operates just like one on the lid of a pickle jar. Simple and reliable.
2. A failed pressure seal will allow the coolant to boil at a lower temperature, and coolant will be able to travel freely and foamily to the expansion reservoir. This will cause localized hot-spots inside the engine, which can lead to premature head warpage, and may hasten head gasket failure. It will also cause the rad coolant level to be low, just like a failed head gasket.
3. A failed return seal will prevent the coolant from returning to the radiator as the rad cools off, causing a vacuum that can collapse the radiator's hoses. This will prevent the coolant from circulating if the hoses don't re-expand as the engine warms up.

Bad Head Gasket (which shares symptoms of bad Radiator Cap) -

When the gasket goes, typically the first thing that happens is that combustion chamber gases are pumped into the water jacket. You will see this as bubbles in the expansion reservoir. This will quickly lead to low coolant level in the engine, and overheating at idle, even if the fan comes on, since the water pump can't move the coolant around properly any more.

If the engine starts to overheat at idle, or in heavy traffic, and the gauge goes down when you rev it, the coolant is low.

The symptoms are similar to a failed rad cap. If you top up the rad, replace the rad cap and the problem persists, the head gasket is definitely questionable. To confirm this, a garage can apply a pressure test (NOT a "compression test"), where air is blown into each cylinder in turn until the technician sees bubbles in the radiator. If no bubbles are seen, the problem is elsewhere, such as an external leak.

This can be accompanied by an expansion reservoir level that is much higher than normal, and which does not go down once the engine cools off.

If you choose to simply add fluid and ignore the issue, eventually oil and coolant will begin mixing together, and coolant will get sucked into the combustion chamber. Ignoring this is a good way to toast a perfectly good engine. Get it fixed early and there will be no further issues.


Bad Thermostat - remaining cool or at COLD during high speed (50 - 60mph) and IMMEDIATELY after getting off highway goes hot. His site also says that many aftermarket thermostats cause many problems. From that overheating guide link again: "Thermostats can stick shut or open, get lazy, or fail to open at the correct temperature. Depending on how and when they fail, they will cause either overheating or underheating. Overheating usually happens when the thermostat fails to open, or fails to open enough. If it fails to close, the engine will run too cool, causing all sorts of other problems."


After reviewing the break down of all possible symptoms I've realized that I should've never put in the 3rd part thermostat in comparison to the rest of what I paid for all the work and parts I should've forked over up to $20 for an OEM Ford tstat HOWEVER the 1st time I pulled over which was the 1st time it overheated since I had it serviced the coolant expansion reservoir was FULL nearly at top and there were SLOW BUBBLES coming up the side of it. ALSO, the engine to me is/was running TOO COOL during interstate travel and continuued to get COOLER as I drove it more so back to the Ford dealership for the 2nd visit recheck. I am now leaning more towards what Ford said unfortunately about the head gasket and possible warped heads because for 1 the head gasket issue does seem likely from what I experienced BEFORE my 2nd visit to them..... thus maybe the tech's excessive revving of the engine just didn't matter but just pushed it to a breakdown point I would've reached later on anyway.

Something else I noticed... my oil level is too high. It is almost 3/4 of the "dot to dot" length past the top dot indicating to me a possible 3/4 to 1 quart overfilled. I cannot recall checking the oil level after I had the shop change the oil before I left for the trip, but if they did top it off at the correct level then maybe this higher oil level is radiator fluid leaked into the crankcase..... however I surely cannot tell cause it looks like OIL..... though it is CONSIDERABLY DARKER than it was just 100 miles ago. Is this from the initial overheating incident or is this cause the coolant is mixing in? BOTH? I looked in the coolant reservoir and there is debris all over the place in there, but it was probably dirty before I had the system flushed way back before even messing with this water pump issue. Still to me the coolant does look darker than it should be for NEW coolant inside the expansion reservoir. I was going to go out and get a new OEM tstat and rad cap, but at this point I don't know if thats going to make any difference at all cause from inspection the rad cap looks just fine and is free of debris, cracking, or scaling.... almost looks new in fact.

I cannot see where the thermostat is to replace it if I wanted to. If I can't see it that means I'd have to remove something..... like the coilpack. I heard it was near there in this thread I think, but I have no clue how to access it.... front the front? from the wheel well?