No heat after washing engine

[John Sawyer]

I used a car wash's high pressure water hose to clean my 1994 Taurus's engine and the surrounding parts, and right after that (in the car wash's parking lot, when I started up the car after the wash), the heater no longer worked, except sometimes, when I'm driving on the freeway, it puts out a little heat for about a minute out of every 10 minutes or so, but it's not consistent. Could I have knocked a hose loose somewhere, or gotten water somewhere it shouldn't have gotten? I checked carefully under the hood, and to my uneducated eyes, it looks like everything is still in place. I've been given the lecture by my brother that I did a dumb thing, though I already knew that. I've seen mention of backflushing the heater core to clear out any junk that might be in it that might cause this problem--how specifically do I do that (where are the hoses, etc)? The coolant level is good, so that's not the problem. And, when I turn the temperature control knob on the dashboard, I can hear the blend door's motor humming appropriately, so it appears to be OK, though I can't vouch for the blend door itself since I can't see it without removing the dashboard, which I'd rather not do unless necessary.

[dddcccmack]

I dont think the heater problem had anything to do with your washing. It was just your time to enter heater hell with the rest of us. Most likely junk in the core . . . maybe a worn pump.
You can flush out the core and it will most likely work . . . for about a month!
Wash out . . drain some coolent out then remove the hose on the water pump. (passanger side 3/4" black rubber hose, goes back and over to the firewall to a "T" the t is a bypass hose which i think, by design, is where the problem is. Follow the bypass hose to the other end (another T) disconnect the other end at the engine. Here what I did . . . use a air hose at either end of the hose ends and blow out the water and some junk. now pinch off the bypass hose and blow it out again. Buy a can of coolent cleaner fill the open ended hose until it begains to run out the other end. Let that sit over night then use a garden hose on either end of the hoses then reverse the garden hose to the other end (back flushing) DONT use to much garden hose presure you dont want to damage the core. Then in about a month you get to do it all over again or until summer. What might help is in stall a filter in the "in" line. theres a cheep filter on the internet somewere . . . Itt or TII industuries ??? Good luck . . Have a happy Holiday.

[mwt878991]

Check your vaccum lines. You may have blown a line off that controls the blend door.

Mike

[John Sawyer]

Thanks for the replies. I haven't had a chance to try flushing the heater core, and I haven't found any hoses not plugged in, but another problem is happening now that's more serious, and probably related: the engine is overheating pretty badly. At first it overheated only occasionally, and only when the car wasn't moving faster than about 40 MPH--when I was on the freeway recently, the engine didn't overheat, though it did on the city streets leading up to the freeway, when I was traveling slower. I suspect the engine didn't overheat on the freeway because the winter air was traveling faster over the engine, cooling it.

Now, I'm not traveling on the freeway, but only around town, and the engine overheats after I've driven only about a mile at 25 MPH. The coolant seems to me to also be under higher than normal pressure, since it's squirting out of a fitting on the radiator where a metal tube enters the left side of the radiator, about three inches below the radiator cap. I keep having to fill the radiator with coolant due to this leak. It's as if the coolant isn't flowing due to some blockage, or something that's not opening up to allow the coolant to flow.

I've bought a replacement thermostat, but I haven't installed it yet, both because I haven't had time, and because now I'm doubtful that the problem is the thermostat, because of a new symptom that happened today: while the engine was cold, I tried to start it up. It wouldn't start the first time, but ran rough instead, so I turned the key again, and it sounded even rougher, far rougher than I'd ever heard it, so I turned it off. I heard hissing from under the hood, and found that the leaky fitting on the side of the radiator was leaking again, even though the engine hadn't had time to get hot. I felt the leaking coolant; it was cold. So now, as soon as I start the engine, it seems that it's creating a lot of pressure in the coolant system, causing the leak--is this further confirmation of a blockage of some sort, or a valve in the coolant system that's not opening up, that should open even when the engine is cold?

Right after I looked under the hood this time, I also opened the coolant recovery reservoir, and saw it was lower than it had been the prior day--it had been high, about three inches from the top, just barely out of reach of my finger, but today it was almost at the normal fill line, indicating the cooling system is generating pressure when warm, and a vacuum when cool, as it's supposed to. As I watched inside the coolant recovery reservoir, coolant blurped from the radiator, into the tank, due to pressure in the coolant system; there were about five or ten blurps, spaced about 10 seconds apart on average, then this stopped. The fill level was still almost the same, though, so not much had gone back into the tank.

Is the thermostat supposed to always be a little open even when the engine is cool, to allow the coolant to start flowing early, and then when the engine heats up, the thermostat opens even more? Or is the thermostat completely closed until the engine heats up? If it's closed until the engine heats up, I assume there are other parts of the coolant system where coolant flows before the engine gets hot enough to open the thermostat, and that's the part of the system where the blockage might be.

To me, the current symptom implies the thermostat isn't the problem, and that there might be something else blocking the cooling system and causing the pressure. It seems that whatever is blocking the cooling system is getting worse fast, as if there's a partially blocked spot with a small hole remaining, that's quickly getting filled in more and more. Or maybe some sensor (maybe the temperature sensor?) that gates coolant according to some measurement it makes, is bad and getting worse? Could the water pump be involved? And does the water pump actually pump the coolant? I'm new to this, so I don't know if the terms "water" and "coolant" in this case are the same thing. If they are, how do I tell if the water pump is working?

Am I on the right track in any of this? I'm not starting the car until I've done a few things like replacing the thermostat, flushing the cooling system and heater core, etc., and some other things to try would be welcome. I've bought a Chilton manual, and I'm pretty handy, so I'll see how much I can do before taking it to a mechanic. Thanks for any further help.

[Millermagic]

I bet the T-Stat is the problem. I had similar problems - last winter it started with the heater not working that well. All of my trips were either on the highway (to utica, 15 miles away) or too short for the engine to warm up. Once it warmed up, I didn't have any heat and it would have terrible spark knock.

I would change the thermostat. You did get a thermostat gasket right? Probably your best bet would be change the T-Stat and then just change the coolant.

[John Sawyer]

Thanks, Millermagic. I agree that the simplest thing I can do right now is to replace the thermostat, which I'll be doing soon (I didn't know they were so inexpensive--$5), but the Kragen where I live didn't have a gasket to go with it, so the sales clerk said it would be OK to use the old gasket along with some gasket sealant, which I also bought, but I decided that if I was going to do it right, I'd be better off buying a new gasket, so I'm going to find one at another store. The sales clerk at Kragen said that once I have the old thermostat removed, I could test it by putting it in boiling water, so I'll try that--I suppose the heated fluid is supposed to make the thermostat's spring retract, which pulls back the thermostat's valve, opening up the path for the coolant. I'll also be flushing the coolant system and the heater core--even though I also need to be spending the time doing other things, this will be a useful learning exercise in my ongoing car education.

I'm still wondering: is the thermostat supposed to be open a little, even before the engine heats up? If so, then if my thermostat isn't open at all at first, it might be causing at least some of the overheating, even if it opens more later when the engine is hot. But maybe it's not open at all when the engine is cold, then opens not enough later when the engine is hot, causing initial overheating, and then more overheating later. Good theory I suppose, but I'll know whether this is what's happening only after I've got the new thermostat installed.

[TaurusKing]

I woukdn't be driving if it's overheating, you're going to damage your engine.. what size engine ?? Hopefully the 3.0 ????

[shorod]

Is the cooling fan working? Before tackling the thermostat, make sure the cooling fan works properly. If not, a new thermostat won't fix your issue. When you're traveling at highway speeds, the air is moving through the radiator on its own, keeping the cooling system cool. As you slow and get into city driving, the cooling fan should kick in to pull air through the radiator.

Also, test or replace the radiator cap to make sure it is properly pressurizing the cooling system. Pressure on the system will increase the boiling point (and freezing point) of the coolant. It doesn't really sound like you have a problem with it boiling over, but the pressure cap is often overlooked.

-Rod

[John Sawyer]

Thanks for the replies. TaurusKing, I agree--I stopped driving the car, and won't be driving it until I've done some work on it. The engine is a 3.8L--is it more likely to become damaged due to overheating?

I should have mentioned that the really bad overheating the car is doing now, started only after I filled the radiator with water from a garden hose, on the advice of a mechanic who posted a reply to a post of mine on another forum--he suggested doing this to get rid of air bubbles that might be in the cooling system, to see if this would fix the car's original problem with a nonworking cabin heater. While I was filling it with water, the exhaust pipe put out a lot of billowing white smoke, and I've recently read this can be a sign of a blown head gasket letting coolant/water into the cylinder, so indeed maybe I have damaged the engine. I'm hoping it's something less serious, so I'll be doing the things I describe above and a few more things before I start the engine again, and see if the white smoke returns.

Shorod, the cooling fan is working--I've heard it start up several times, but I haven't taken the time to notice if it starts up every time the engine has overheated--I'll watch for this. I've also thought of replacing the radiator cap due to possible pressurization problems--they were right next to the thermostats at Kragen's, but I didn't get one since at the time I thought the thermostat was more likely. But I'll buy a radiator cap and install it before starting the engine again, since they're pretty inexpensive.

I also noticed a couple days ago, while looking under the car, that the bottom front edge of the radiator's fins are somewhat crunched, probably when I or someone else driving the car before me, drove into a concrete parking stop or a curb or something similar, which is something I'd done a couple times prior to the overheating beginning. I haven't looked at this closely to see if any of the radiator's cavity has been crunched, but I'll be doing that tomorrow.

I'm hoping that once I'm finished with this process, I'll have some kind of idea what it was about washing my engine that led to all this, or if something else unrelated happened just after I washed the engine that caused the engine overheating.

[Huney1]

"Is the thermostat supposed to always be a little open even when the engine is cool, to allow the coolant to start flowing early, and then when the engine heats up, the thermostat opens even more?" There's a way for coolant to purge/bypass around the t'stat. The, "start to open," temp is the t'stat setting, say 190F, when it cracks open and continues to open until it's fully open at operating temp, usually 200F. Good way to check a t'stat is put it in a pan of water with a thermometer and turn the heat on and see exactly when it cracks open which should be the degrees stamped on the t'stat.

"Or is the thermostat completely closed until the engine heats up?" No, see above.

"I'm new to this, so I don't know if the terms "water" and "coolant" in this case are the same thing." Yes, they're the same. Coolant generally refers to water & anti-freeze mix.

"If it's closed until the engine heats up, I assume there are other parts of the coolant system where coolant flows before the engine gets hot enough to open the thermostat, and that's the part of the system where the blockage might be." The coolant circulates to some degree but not enough to move nearly as much as it does when t'stat is fully open. My 03 Vulcan stone cold and I turn the heater on high temp it takes about two minutes to start making slightly warm air and gradually gets hottter n' hotter like it should. That's with ambient around 40-50F.

At this point you should eliminate the possibility of worn out water pump blades because the bladles and t'stat determine the volume of water moved through the engine & heater. If the blades, t'stat, hot-cold coolant heater valve and the vacuum doors are working properly, then look to a clogged heater core. Oddly enough, with worn blades it will pump enough coolant to keep the engine cool but not enough to keep the heater core hot.

Elsewhere I saw directions for blowing out the heater core which is the best quick fix going, but if the water pump blades are severly worn then you're wee-weeing into the wind for distance. If you do blow out the heater core, TAKE CAUTION because typical garden hose will make 60 PSI and if you over pressurize the core it will start leaking. And, as always, NEVER attempt to work on a hot engine and let it cool down at least an hour first.

Engines run close to boiling point of water 212F so if you make an error and get a face full of coolant it is a painful disaster and/or serious burn that can scar and disfigure the face and/or other parts of the body. Long time ago an old Dude told me, "Treat a hot engine like a Rattlesnake, one error and you're bad hurt." Getting cut is bad enough, but I'd take five cuts instead of one burn.

BTW, good idea to wear safety glasses because if you get a squirt of antifreeze in your eye it will make you call fo' yo' Ma'ma and 'prolly lose half your religion to. AARRGGHH! It Burns!!! (The Exorcist.)

[Huney1]

"Now, I'm not traveling on the freeway, but only around town, and the engine overheats after I've driven only about a mile at 25 MPH. The coolant seems to me to also be under higher than normal pressure, since it's squirting out of a fitting on the radiator where a metal tube enters the left side of the radiator, about three inches below the radiator cap. I keep having to fill the radiator with coolant due to this leak. It's as if the coolant isn't flowing due to some blockage, or something that's not opening up to allow the coolant to flow."

Long shot, but here goes. You fill it then get home and park it for the night. coolant runs out then cools off and draws air into the system through the leak. Remember physics 101 hot gases expand - cold gases shrink? Now you have air in the system and fill it up in the morning trapping air in the heater core and there's the problem. Get the leak fixed first then if the heater works good to go. If not check the water pump blades & t'stat and if no go then G E N T L Y blow out the heater core. If it don't work then sit a can of Sterno in a bucket and rock on. (Just kidding). Don't do it! I did that with an old VW once when we were stoned zonked and nearly asphyxiated all of us.

[Millermagic]

Or you could just be like me and not use the heat at all. The only time I use the heat is when someone is with me. If it's 0 out and the windows fog up, I open a few.

[Huney1]

Zero degrees and you ride in a car? Brrr! Haven't done that since I was in Germany in 1961-2 and only reason I did it then is I was on duty and didn't have a choice.

[Millermagic]

I've had bad experiences with heat and driving ... and sleeping.

[seasonalskier2006]

an easy way to check if it is a blown headgasket is:

when the engine is COMPLETLY cooled, not even a slight bit warm, take the cap off and have a friend start the car. Then take a flashlight and look into the radiator and see if you can see little bubbles almost like it is boiling. If you see any bubbles whatsoever, stop driving the car. That is a sure fire blown headgasket, and if you are new or even semi good at cars, bring it to a shop. They are a bitch to repace and damn near impossable for most people. Also what motor is in your car, the 3.0L or the 3.8L, this can help diagnose the problem more than you would think.