Engine/Transmission (1998.5 - 2002) Overheating

[Troubleshooter]

Guys, I need some help on diagnosing the cause of my truck’s overheating problem. The truck is an ’01 with AT and mods as shown in the profile. I’ve been having an overheating problem (transmission and engine) in heavy traffic (stop-and-go or < 10mph).

It was almost due for a coolant change anyway, so flushed and changed out coolant and it seemed OK until back into heavy traffic. It was especially bad last week when a collision on the interstate placed me in stop-and-go for over an hour – transmission temperature got as high as 220*F and the engine temperature was nearly to the upper limit of the “normal” bracket. I was able to keep it from overheating only by shifting from Drive to Neutral and revving it to get more airflow. Once we got to the exit and started driving 10-15mph the engine cooled down quickly and seemed to run just a bit hot, but not exceptionally so. This was with no load and no trailer; and an ambient temperature of about 85*F.

Since then, we tried changing the thermostat but to no avail. So since it was still the original radiator, we changed that out as well. Although the temperature at cruising speed seems about 5*F lower, it seems to have had no effect on overheating during low-speed or stopped situations (current ambient temperature is 95*F, or roughly 10* hotter than during last week’s problems). Mechanic looked at the fan clutch and said that it appears to be OK. Next thought is maybe to check the water pump.

EDIT: Although the mechanic scanned and found no codes stored, I tried again with the SMARTY and found code P0217. Wondering now whether I need to re-flash or replace the ECM or something.

P0217 Decreased Engine Performance Due
To Engine Overheat Condition
Engine overheating. ECM will derate engine performance.

Any other ideas? The overheating problem seems to occur only in Drive.

 

[SAndreasen]

I'd try the fan clutch did he actually test or did it just look OK ? I just got through fighting the same problem on my truck it turned out the radiator was plugged I would also try washing the intercooler and ac condenser

 

[Troubleshooter]

I'd try the fan clutch did he actually test or did it just look OK ?

Not sure exactly how one goes about testing the fan clutch. Could you expound?

The manual says that it should have minimal resistance when cold and some resistance when hot, but it seems to be the same to me regardless of engine temperature. I should mention that I have not heard the loud noise of fan clutch coming on for quite a while though.

 

[SAndreasen]

I would check that the intercooler is clean pull it out and wash it they can look clean but be plugged

 

[Troubleshooter]

Thanks, I'll try washing the intercooler and see whether that does any good.

Do I need to do anything about the P0217 code? I've cleared it with the SMARTY, but if the ECM is derating the engine, is there something I need to do to the ECM?

 

[JR]

The 0217 is just telling you the ecm derated the engine when it overheated. Once temps come down to satisfy the ecm power is restored if you didn't already cook it.

I would pull the water pump and inspect the fins. Kind of a shame since you just had the system drained to do the radiator but you can drain the coolant into a clean bucket and reuse it. Or if you didn't do a flush now is the time to do it. If the pump looks good then the fan is really the only culprit left.

 

[Troubleshooter]

Thanks JR. Yes, it would have been better to pull the water pump when we replaced the radiator. We'll see what happens next.

 

[KATOOM]

A few general things to look for before you go tearing the engine apart.....

If the engine blowby vent catch bottle hasn't ever been relocated then over the years the oily blowby vent air coming from the engine gets tossed around the front of the engine and radiator and the oily residue collects dirt in the radiator slowly cutting off air flow. Usually this means that the A/C isnt that cold at idle or when moving at a snails pace either but will get cooler as you get up to highway speeds. A partially clogged radiator from the blowby vent is something which cant be visually seen either since it doesnt affect the intercooler so if this is the probmel then you really need to just remove the radiator, spray it down with degreaser and just hose it off. You can try it without removing it but I dont know how well it will work. Dont use high pressure either as you'll fold the fins very easily. If the catch bottle has been relocated then this most likely isnt the problem.

The other potential problem is a bad engine fan clutch. Especially if the OEM fan clutch has ever been replaced with a parts store cheapo unit. The Cummins clutches are what you want to replace it with if it even needs to be replaced. You can quickly test the clutch too with the engine off. Again, engine OFF, open the hood and grab the fan blade. Give it a tug/wiggle and it should NOT have any sloppy movement in any direction. Then give it a spin by hand and see if it offers resistance. It wont want to free spin more than a few inches if its in good shape. The fan clutch doesn't "fully" engage until it registers 205* at the front radiator side of the clutch and when it does it will ROAR pretty loud because at 2000 rpm its pulling 10,000 CFM. Thats a lot of air.

Also that code wont pop up until the engine reaches 226* but it should go away when the coolant temp drops back down.

 

[Troubleshooter]

Thanks, I relocated the blowby about ten years ago, and the radiator was pretty greasy at that time. For the current problem, this no longer matters, as this is a completely new radiator as mentioned in the original post. Today, we pulled the water pump (impeller fins looked good), and ended up replacing the fan clutch. I was not there at the time, but he did manage to get it about 1/2 between the middle (180* mark) and the right side of the "normal operations" bracket (which I'm guessing marks 210* or so). So it was roughly 200* or so which is hotter than normal but not nearly as bad as it was in traffic the other day. Today's follies took place at roughly 97*F and it heated-up ONLY when it was idling in drive. So, never did hear the fan-clutch engage today. Of course, we didn't hear it last week when the original problem manifested iteself, either.

He seemed to think that the engine was idling a little fast and might be working against the transmission, possibly causing the higher temperatures, but I thought it was idling normally. Problem is neither my Haynes manual nor his reference books shows what normal idle should be for the '01 model year. My Haynes does show that a '96-99 should idle at 800rpm in Neutral and 750 or so in Drive.

 

[KATOOM]

I understand that your idle RPM's are fine. Adjusting the idle means messing with the APPS too and it highly suggest NOT to touch since its easy to send the whole thing off calibration. I'm not there but it sounds like the fan clutch is just too weak. Like I mentioned, the OEM Cummins fan clutches have proven to be considerably stronger than anything you can get over the counter at the parts store. Its a misnomer that the fan clutch only engages when the engine temp gets high. Its strength at idle is what keeps the air moving and your A/C functioning too.

 

[wcjp]

Your profile does not indicate what part of the country you live. If hot in stop & go in Texas Summer with an automatic transmission your problems sound minor. Especially if it helps when going to Neutral. If this condition happens in Canada or Alaska winter your problems are more severe.

 

[Troubleshooter]

wcjp: I would think that the operating location would be more relevant than the garage location. FWIW, the first time this happened was in Arizona and 110*F heat, the second time was in Iowa and ~ 85*F heat. In both of those instances, the truck was lightly loaded and not towing, as mentioned previously.

The new fan clutch seems to be working much better at keeping temps cooler. I was pulling a trailer thru Amarillo today and never got much above 200*F or so. What surprised me was that when the needle got just barely above the 190*F mark (guessing 195-200*F) that I'd hear the fan kick in. Sometimes it dropped the temp back into the 180's and sometimes just maintain it around 190*F but it did seem to work at keeping things cooler. We'll see how it holds up over time and more road conditions.

 

[tugboat1st]

Cummins said they don't supply fan clutches for Dodge applications. That has to come from Dodge.

 

[KATOOM]

The OEM clutch fan for the 2nd gen trucks are part number 52028894 (00-02) and 52028615 (98.5-99). Venders like Geno's Garage has them too.