Engine/Transmission (1998.5 - 2002) Over heating!!!!!!!!!!!!!

[bsappington]

I was traveling from Seattle Wa. to Reno, Nv. and had some trouble with my truck overheating. I was going over a couple of passes between 5,000 and 6,000 feet hauling a 32 ft. trailer. The air temp. was well over 100 degrees. I think that this is normal. However it started to act like the Ottomind was not functioning the boost would not go above 10 psi until I let off the go pedal. Then when I got back into it the power and boost would come up then go for a little bit then fall off again. When I got to Reno and stopped at the RV park I shut the engine down for about 15 minutes. When I came out it would not start. It cranked on and off for about 5 minutes then finally started.

I have been driving the truck for a few days here in Reno with no problems. Since I going to be here for a little while I was wondering what was going on.



Thanks,

Ben

 

[RJPotts]

Just wondering, during that trip were you running the A/C most of the time? The problem you're describing sounds like a VP electronics problem to me. Mine gets hot and runs like crap too, once its cooled down though, runs fine.

The hard starting is what I would worry about. Check for codes and post back.

-R. J.

 

[HEMI®Dart]

Ben,

Are you still running the OEM T-Stat? That year truck may have had a bad T-Stat from the factory.



Overheating while towing: reports appearing of bad thermostat batch

replace thermostat : Cummins P/N 3943200



TSB: http://dodgeram.info/tsb/1998/07-08-98.htm

 

[bmoeller]

Something I'm curious about. Do the ISB engines have a sensor to monitor fuel temp?



From what I was told, there some manufactures that have them, and when the fuel gets hot enough, it will de-rate the engine or shut it down. John Deere is doing this now. I think it is just their HPCR engines, though.



Just a thought.



As far as the coolant temp, check to fan clutch for proper operation, plugged fins on the radiator or any of the other coolers and the thermostat.

 

[bsappington]

Sorry that I have not returned answers to all the questions. My computer crashed and I just got it fixed.



To start with I was running the A/C pretty hard. I am not sure that I am following how this affects the VP 44 electronics. I believe it could I just don't understand how.



I am curious about this thermostat deal. The temp would climb so high and hold for a minute and then just bury the needle. The whole cooling system appears to be fine. I was thinking maybe the condenser was causing heat to travel to the radiator.



I think I like it better in Seattle were the ambient does not get over 85 degrees most of the time.



Thanks,

Ben

 

[JimKing]

If you haven't actually PULLED the radiator and checked it, you may be suprised. I pride myself on keeping a spotless engine compartment and drivetrain, I wore out a pressure washer cleaning it. recently I had a overheat problem where the temp would go to the last mark in the normal range, hang there then suddenly shoot to "Hot as He**", even made the "check guages" light come on. Visually the radiator look great, but I pulled it anyway. . I was dumbfounded to see that it was totally plugged inside the shroud area. couldn't see it looking down at it. Had it boiled and rodded, inside was cleaner then the outside. The puke bottle apparently blows enough oil vapor onto the radiator to plug it solid with oil and dirt after 107K. Pulling the radiator is a 30 minute job, you may be suprised what you find... Oh yeah. . Move the puke bottle while you have the radiator out. . Lots of room to work. .

 

[bsappington]

Mostly I was wondering with a 32 ft. travel trailer and 6,000 ft. with the air temp at above 100 degrees is this normal to see over heating problems with the cooling water. Also I have my exhaust sensor post turbo. In the installation instructions from Banks it says to mount it pre turbo. I bought my truck with the system already installed. It has a BD exhaust brake and who ever did the install placed it there. I was wondering if the Ottomind is not getting the proper temp it needs to run properly. I don't let the temps get above 1000 degrees because of the differential but I have been kicking the idea around about changing it.



Thanks,

Ben

 

[PKozlowski]

I had an over heating problem also. Put in a new thermostat, still ran hot.

New clutch fan (twice), still ran hot! WHAT???

What I found out is that the little breather bottle on the front of the engine

was full and over flowing. Look between the radiator and intercooler.

Mine was partly clogged.

So much for the dealer doing what I asked, empty the bottle at oil change.

 

[jandtjil]

bsappington

I think the problems aren't that out of norms, high and hot with a load (were you keeping the revs up to control egt and trans heat?).

I wouldn't want to gues whether the pre/post sensor location would affect the ottmind, i'll refer that to smarter folk than me.

Can't say that it made mine run any cooler, but at 50K miles I too had a deposit of goo forming on he lower part of radiator from puke bottle.

If you do a search there are directions on how/where to mount, I moved mine down to the sway bar, a 30 min job.

JJ

 

[Texas Diesel]

What my bottle did to the radiator. This is the front side, the back side was worse.



Bye bye worthless bottle and hello longer hose.

 

[ToolManTimTaylor]

The Ottomind starts to defuel close to 1300* egt and defuels allmost all together once 1300 is reached. Under those conditions described I will bet that you were riding close to 1250 and she just started to stack heat until it soaked up twards 1300. And sure 100 degrees at 6k with a big trailer will run the engine warm to begin with . . stock! Now with all that hot fuel returned to the tank it was like flowing water which isn't the best thing for a stock system to try and pump (I did not look if you had modded it).

 

[bsappington]

As far as I know the breather on my truck does not has a bottle. I would think this would make build up in the radiator worse. I will try to check it however since I am not at home, I'm at a job site building a powerplant it is not easy for me to take it a part.



Thanks,

Ben

 

[Bobalos]

Good afternoon Gents,



what would you guys consider hot? Mine normally runs right @ 190* w/o Load & 1/2 way to the "high" mark (220* I think, I dont have the truck with me right now). this Saturday with 102-103* ambient conditions towing my 8000Lb load, it got up towards that mark. Mind you I was going up a pretty darn steep hill, so I did not think much of it. I backed out of it a bit, brought the EGT's & Boost down a bit & pulled over & let it cool (& let traffic by). after about 20 minutes I took off again & it went right back up there & pretty much hung right there.



I dont remember it doing this before (same trailer load & hill, although cooler ambient levels).



on the way home it was about 70* & it still ran a bit warm, but once I got onto level ground, it went back to "normal".



my question is, where should I start to get nervous? 220*, 240* ????



BTW, its a stock, '99 3/4 Ton, 2wd, Auto, extra cab, with gauges.



thanks a bunch.

Bob

 

[RustyJC]

Ever since it was new, mine has run 1 needle width below the 190* mark running empty and 1 needle width above the 190* mark when towing, even in 100*+ ambient temperatures and in the Texas Hill Country. To me, that's normal with a 190* thermostat.



Rusty

 

[MRose]

I too had the pyro probe mounted in my BD exhaust brake, they way I bought it. Always kept temps under 950*. Moved my probe to the manifold and was getting the temps over 1500* in the same conditions the I had 950*post turbo. So be aware! Move your probe!

 

[Huff N Puff]

If you have more than 30000 miles on your truck,please heed the warnings about the breather bottle and pull the radiator clean it with engine gunk it will suprise you how much debris is in the radiator.

 

[PKozlowski]

Hay, MRose, this is not directed at you but at this exhaust temp

problem we all seem to have. It just drives me crazy NO one has

the correct answer.



Some mechanics say going up hill the max pre-turbo should be 1150.

Some say 1250 is all.

I've even heard some people say 950 pre is max going up hill.

Heck if that is true I'd be going backwards.

You talk to another mechanic and he says who cares,

just run the truck!



So here we're at the same ol question, which temp is the one to run by?

If I run PRE turbo up hill at 1150 deg it takes all day to get up the hill.

But if I run 950 post(1500 pre) then I'm way over temp.



So am I correct in thinking 1500 pre turbo is ok ?

I think I'll just take the gauge out and drive my truck.



This exhaust temp is a pain in the a@@. No one seems to know

what the "correct" temp is and Cummins is no help when I asked them.

If anyone should know what the "correct" temps should be it should

be them! They know what all the parts are made of and what temps

they can withstand and for how long. I think it's pretty simple to

figure out but what would I know.



Another question, why can the big trucks run up hill as hard as they can?

A couple of friends of mine drive and they have egt's.

They said the gauge only goes up to 1550 deg and it's normally

maxed out and they're trucks have been running for years and years

like that no problems.

They said they don't even use the gauge and I should just drive

my truck the way it was designed to be driven..... Hard...

So I'm going to go with they're suggestion. Just run it.

They both said they run by the water temp.

If the water temp goes up to much take my foot out of it,

until then I'm not going to worry about it.



My thinking anymore is if it was that important the truck would

come with an EGT from the factory. It doesn't.

Cummins doesn't even recommend one!



Sorry guys had to vent about all this turbo / egt crap.



I'll get off my soapbox now.

 

[RustyJC]

In my mind, the EGT question is pretty easy to answer. I installed my gauges when my truck was box stock except for the Jacobs exhaust brake, which the dealer installed before I took delivery. Maximum EGT when towing in stock configuration was 1300 degF pre-turbo.



Obviously, Cummins and Dodge are comfortable with 1300 degF pre-turbo EGTs as that's how they built the truck, and many hundreds of thousands of them are hammering around the highways dragging trailers with no pyrometers - no idea of what the EGTs are running.



So, when towing up grades, I use a self-imposed limit of 1300 degF or less - generally about 1200 to 1250 degF on the long grades. Since that's equal to or less than the stock engine, I know that I'm operating within the thermal limitations of piston crowns, exhaust valves and seats, turbine wheels, etc. Could I run it higher? Probably, but I'm an old man who doesn't want to walk home.



Rusty

 

[Texas Diesel]

. It just drives me crazy NO one has

the correct answer.

Great post, I feel the same way.



Speaking of OTR trucks, when we fillup at truck stops I watch the drivers fool around under their hoods. One thing I have noticed consistantly is their turbo chargers are never yellowed from heat like mine is. They all have a nice grey clear coat appearance. If they run 1550F regularly why arent their turbos yellowed like I've seen ours?

 

[PKozlowski]

Good point RustyJC. Walking and pulling my trailer home on my back... .

lets not go there. ;-)



Texas Diesel.

And I notice some are yellow / rust color and some aren't.



My turbo is a metalic gray color. Part of the exhaust manifold is purple.



I did write a note to Cummins again this morning asking them to settle

this once and for all.