My wife called and said my 2000 Rodeo overheated and wouldn't go. She said she was driving up a hill, with it floored, and going like 10 miles per hour. She said when she got out she could smell it was really hot, and that the water temp gauge was at H. I won't get a chance to look at it until tonight but any advice as to what I should look at?

I have 105K miles on it, and less than perfect maintenance except for regular oil and tranny fluid changes, as well as a few diff. fluid changes. I'm getting ready to do the BIG overhaul, timing belt, water pump, etc... I had it in the dealership earlier this week because of a leaking accumulator on the Tranny which they fixed, and a check engine light that they said was my EGR valve. The EGR shouldn't cause it to overheat though.

It's never done this before. What could cause it to overheat and lose power like this? What should I check out? Thanks for any advice...

I believe the newer 3.2/3.5's, maybe 2000+ will go into 'reduced power' or limp mode if the coolant temp gets too high. This may be what your wife experienced. The 1998+ seem to lean out and get super hot on long WOT runs. Make sure your coolant and radiator are clean. You'll want to do an oil change as well. EGR does cool the combustion chamber, but EGR shuts off at WOT so I don't think that was the cause.
G/luck
Joel

first thing I would do is check the oil, make sure it looks normal and not milky or contaminated with coolant, that would be a sign of a blown head gasket. Then I would definately do what the others said, coolant temp sensor, thermostat, maybe even a cooling system flush wouldnt be a bad idea, make sure its all up to parr.

Not sure what percentage of grade you're refering too - but I live in Colorado's high-country, and I have the older 3.2L Sohc automatic, this truck does superb up here, but is crucial that it be in the correct gear.

I'm not aiming to sound rude or make you or your wife feel foolish, as some people honestly do not know that they are supposed to switch to a lower gear to assist the engine in a steep grade, but, if your truck is an automatic, I hope your wife used either the "power mode" or shifted to a lower gear, i.e. 3rd or even 2nd depending on the grade percentage.

If she left it in just "D" without Power Mode, she probably overworked the tranny and caused the truck to overheat. As the tranny is connected to the engine's radiator on these trucks, and if the engine overheats, so does the tranny.

I can guarantee you, if the grade of slope was that of similar to some of ours here, your tranny's probably fried, and the engine may have been trying to compensate and overworked itself.

If she did use the power mode or switched to a lower gear - then hopefully the tranny won't be too effected by the overheating.

I would definitely not only address the engine, but make sure to put some fresh tranny fluid in as well - as you can be assured it got real hot as well.

Keep us posted.

Yep. Good call. An overheated engine = an overheated transmission since the engine & trans share the same cooling system. The 4L30E like any other automagic doesn't handle heat well. You will need to atleast do an ATF change. It's not a bad idea to switch down to a lower gear (3 or even 2 instead of D) if the trans hunts around on a loooong incline. If the trans is not hunting, leave it in D.
G/luck
Joel

It's not a bad idea to switch down to a lower gear (3 or even 2 instead of D) if the trans hunts around on a loooong incline. If the trans is not hunting, leave it in D.
G/luck
Joel


At 10mph with the truck floored, it was long past hunting for the right gear - it needed to be down-shifted for sure. That's asking a LOT from the engine and tranny at 10mph with the truck floored in Drive.

Hopefully it was in 2nd gear.

Ramblin, With the truck in "D", if it's staying in 4th gear at 10mph, it's got problems bigger than the hill it's climbing! It should have dropped down to 2nd all by itself at that speed.

Joel

So very true.

Forgive me, it's just that I was taught to downshift a lot when learning to drive in the state of Colorado, and I always forget that the truck theoretically should do it on it's own.

I don't like to wait for it to hunt, I give it that extra umph before I even start the climb, i.e. truck's always in D with Powermode from the very first mountain going up I-70. Just my choice in driving style.

The 'hill' couldn't be much of a hill. We're in Austin TX area, and hills here are small mounds of dirt compared to the hills up in Colorado. We made it through the HOT summer down here without any problems. The temp gauge is always right at 50%, even in 100+ deg. and AC on high. I've suspected that the AC system has been weak for awhile which might have been a symptom of what's going on now? I had it charged up in the summer and it didn't make much difference. I thought it might have just been that the Rodeo's AC design couldn't tackle the 100+ deg. heat.

Surfing the forum I came up with a list of things to look at. I'm fairly new to auto repair, so I sometimes don't really know what I"m looking at or looking for, so I'm hoping you all can point me in the right direction.

One of the first things I thought I'd check was the fan and fan clutch. The problem was happening in traffic, but not at speeds. I started it up and let it run for 10 minutes or so. The temp gauge went right to 50% like it normally does. I had read some things about the testing the fan clutch, but I'm not really sure what to check. I took a fairly soft brush and held it against the fan and it stopped with little effort. I can hold the fan from rotating with very little effort. Is this normal?

Radiator seems to be full and fine, but I'm sure it can use a flushing.

I just changed the oil about 200 miles ago. I was planning on running some sea foam through it before the next change, but perhaps I'll just do that now.

The dealership who replaced my accumulator seal should know how to properly refill the transmission, but I haven't double checked it. Transmission fluid had leaked out far enough that I was having some pretty bad tranny slipping. Maybe it was damaged to the point where it is causing the overheating? The tranny could point to why it doesn't overheat just sitting in my driveway and it does when moving in traffic.

Thanks for any feedback.

Cheers.

Curious if another possibility could be the engine thermostat??

Tranny is still a thought, to me, as the truck still should have downshifted in WOT at 10mph. The previous low fluid level could be causing issues. Do you feel it slipping at all - now?

The choice of engine oil shouldn't have anything to do with the overheating, the only possibility that I could see it being a factor is if it was low on oil, but they generally don't overheat, you just seize the bearings.

I wouldn't worry about running seafoam through your crankcase, in fact, that's the last thing I would consider doing on a perhaps questionable headgasket - as the engine did overheat.

But I would change the oil for sure - look for a milkshake appearance. If it looks like a chocolate shake, your headgasket is bad.

The heads/block are all aluminum on these 3.2L's, unfortunately it doesn't take much to cook them either, warping the heads.

..One of the first things I thought I'd check was the fan and fan clutch. The problem was happening in traffic, but not at speeds.

That's a good possibility. Man I hate clutch fans! :banghead: . The fan should pull air thru the radiator at full force at idle and low RPM conditions on a hot engine. Fan RPM's should subside as engine RPM increases. If the overheat happend after a bunch of stop n' go, maybe the fan clutch is not working right. Like ramblin said, a T-stat is another possibiliy. If the T-stat doesnt throttle coolant flow properly, coolant doesnt stay in the radiator long enough to remove the heat. Another thing to look for is the electric fan (a/c equipped rodeos) between the grille and condensor. That fan should come on when the a/c is on once the truck is warm. Maybe the electric fan is caput?

G/luck
Joel

The electric fan seems to be working fine. I'll change the oil tomorrow hopefully to look for the head gasket leak. How big of a job is replacing the thermostat? Should just ask them to replace that when I take it to have the radiator cleaned and flushed?

What's the difference between the $86 Imperial fan clutch, and the $136 Hayden fan clutch at Advance? Napa has one for $104 as well.

Hayden has a $120 and an $80 fan clutch at o'reilley with exactly the same descriptions. Now I'm really confused....

How much force does a fan clutch typically put on the fan when it is engaged? The fan spins up slowly, but it's pretty easy to stop with the brush. I wouldn't stick my finger in there to stop it, but I can hold it with a pinky finger when I have it stopped.

You have to pull the common chamber (upper intake) to r/r the t-stat. It's burried under there. I dunno how to troubleshoot the fan clutch, other than they usually ROAR all the time if they go bad (kills alittle engine power and MPG's if that happens).
G/luck
Joel

The electric fan seems to be working fine. I'll change the oil tomorrow hopefully to look for the head gasket leak. How big of a job is replacing the thermostat? Should just ask them to replace that when I take it to have the radiator cleaned and flushed?

What's the difference between the $86 Imperial fan clutch, and the $136 Hayden fan clutch at Advance? Napa has one for $104 as well.

Hayden has a $120 and an $80 fan clutch at o'reilley with exactly the same descriptions. Now I'm really confused....
I paid $60 at AutoZone for a fan clutch with a lifetime warrantee. Don't remember what brand it was though.

The more I think about it- the fan clutch should offer some resistance if you stop the fan blades at idle like you did with a soft brush (safety first!) No resistance would indicate a bad clutch, as would a fan that ran at full speed (roared) thru all RPM ranges. Some resistance = good and a fan that slows down at higher RPM's = good.

G/luck
Joel

Don't rule out the EGR as part of the problem. Someone in this forum can correct if I'm wrong, but isn't one of the EGR valve functions to cool the exhaust????
From what I have read, a clogged EGR will cause the exhaust headers to overheat, therefore heating the engine???

Well.. I can't recreate the overheating.... I do think the fan clutch is bad, or on it's last leg, so I'll probably replace that.

I got a new EGR and installed it last night, my old one was probably fine but I got a good deal on the new one. Cleaned the tube into the common chamber, it wasn't blocked, but it was pretty dirty. I'm still getting the check engine light, so I'll take it by autozone to get it read I guess.