Overheating

Jim Johnson · July 3, 2008

Got a question. I have a 8.1 that almost overheated (got to 250 temp) pulling a hill with my 5th. It cooled off and it ran fine. Question is when it cooled down the upper radiator hose colapsed. Opened the cap and it opened back up. Replaced hose anything else I should worry about.

merlin5577 · July 3, 2008

Got a question. I have a 8.1 that almost overheated (got to 250 temp) pulling a hill with my 5th. It cooled off and it ran fine. Question is when it cooled down the upper radiator hose colapsed. Opened the cap and it opened back up. Replaced hose anything else I should worry about.

You are very luck you didnt damage anything else (like a head gasket). If the engine hit 250 I am willing to bet your engine oil and transmission got pretty hot too. Depending on what temperature the transmission got to you may want to do a transmission service on it to swap out the burnt fluid. Also I would suggest an oil change. When the engine gets that hot the oil gets even hotter and above 300-350 degrees (especially for long periods of time) it starts to get nasty. Good luck.

ZZ327 · July 3, 2008

you might want to do a coolant top off, or flush it and check out your thermostat too.

merlin5577 · July 3, 2008

you might want to do a coolant top off, or flush it and check out your thermostat too.

ZZ is right. In my post I assumed you had already done that. My mistake.

Jim Johnson · July 3, 2008

I did get very lucky. I am planning on doing the trans and engine oil. The oils are pretty dirty now. The only thing that made me fell ok after it cooled off was that I run synthetic oil in it. Should I replace the cap and thermistate (can't find the spell check). Heard of anyone that had this problem?

merlin5577 · July 3, 2008

I did get very lucky. I am planning on doing the trans and engine oil. The oils are pretty dirty now. The only thing that made me fell ok after it cooled off was that I run synthetic oil in it. Should I replace the cap and thermistate (can't find the spell check). Heard of anyone that had this problem?

You can replace the cap and thermostat as preventative maintenance. Depending on the circumstances (outside temp, hill grade, amount of trailor weight, vehicle speed, etc...) it may have just been a one time thing. As long as it doesnt happen all the time I wouldnt worry.

Jim Johnson · July 3, 2008

Thank you for your advise merlin5577

merlin5577 · July 3, 2008

Thank you for your advise merlin5577

Anytime. And welcome to the site.

Killerbee · July 3, 2008

Did your fan engage?

The flat hose comes from a bunch of coolant caps that don't purge. You may have air in your system if it can't degas on cooldown. Sometimes replacing the hose with a new less compliant one will temporarily fix the symptom, but it will probably happen again.

Back to the fan, it should have been very loud and obnoxious if it was working.

merlin5577 · July 3, 2008

I am pretty sure his truck has a mechanical fan. I dont know about the big block engine but on my truck you cant hear it when its engaged.

Jim Johnson · July 3, 2008

You know I am glad you said something about the fan. I was so focused on the temp I do not remember hearing the fan come on and that thing is loud. It is a macanical fan so I will need to look at the clutch on it. Thanks again.

merlin5577 · July 3, 2008

You know I am glad you said something about the fan. I was so focused on the temp I do not remember hearing the fan come on and that thing is loud. It is a macanical fan so I will need to look at the clutch on it. Thanks again.

Thats a good idea if I ever heard one!

DJHooks · July 15, 2008

Have a 05 2500 HD, pulling a small camper and overheated half way up Tajon in California. The motor shut itself down and after a while after it cooled I could turn the motor but it would never turn over. I have it in a Chevy shop in Valencia CA and i am getting some conflicting answers as to the problem, cost to repair and time to repair. I dropped it off late Thursday night and was told Monday evening I would have a update as to the problem. My phone call yesterday went like so; we are waiting for a call from the manufacturer to see if it is covered under warranty, we are trying to save you some money, it could cost as much as 2-3k, we are waiting for a call from the manufacturer before working on the truck, after I told them to fix the truck as it is mine and not the manufacturer I was told it could cost as much as cost 5-15K. I told them to fix it regardless as i am currently standed with family in a camper. My questions are, does this seem simi normal for a over headed duramax? I understand schedules and that we are business to prosper but I cannot help but feel that i am suffering from a overdose of BS.

ctfan · July 15, 2008

Have a 05 2500 HD, pulling a small camper and overheated half way up Tajon in California. The motor shut itself down and after a while after it cooled I could turn the motor but it would never turn over. I have it in a Chevy shop in Valencia CA and i am getting some conflicting answers as to the problem, cost to repair and time to repair. I dropped it off late Thursday night and was told Monday evening I would have a update as to the problem. My phone call yesterday went like so; we are waiting for a call from the manufacturer to see if it is covered under warranty, we are trying to save you some money, it could cost as much as 2-3k, we are waiting for a call from the manufacturer before working on the truck, after I told them to fix the truck as it is mine and not the manufacturer I was told it could cost as much as cost 5-15K. I told them to fix it regardless as i am currently standed with family in a camper. My questions are, does this seem simi normal for a over headed duramax? I understand schedules and that we are business to prosper but I cannot help but feel that i am suffering from a overdose of BS.

The 04.5 and 05 Duramax's are known for over heating. There really isn't much your dealership can do about it. Check out dieselplace.com and do a search on the overheating problems. There is an aftermarket radiator fix for it. Something else might have happened to the engine when it overheated and actually shut the motor down that would cause the price to be that high.

dewfpo · July 15, 2008

Did you get any warnings such as dash lights? pegged gauges?, DIC warnings?, unusual noises? bad running? bad shifting? etc... before the truck shut itself down?

Just a point of clarification : If you turn the key and the starter engages the motor and it spins, then it is "turning over" or "cranking".

DEWFPO