Chevy and GMC Duramax Diesel Forum banner

1 - 4 of 4 Posts

·
Registered
Joined
·
3 Posts
Discussion Starter #1
I have a 2010 3500. When towing my 38 foot 5th wheel my coolant temp gets up to 230 and I have to back way out of the pedal to get it to cool. I have replaced the thermostats, fan, fan clutch, both fan shrouds, and the radiator. Is this normal temperature for an LMM?
 

·
Registered
Joined
·
1,846 Posts
It is probably normal, depending on the conditions under which it occurs. Temperature, altitude, speed, throttle position, boost, torque converter lockup, etc. The more power needed, the more heat the engine produces and the higher the coolant temp will go. If you are towing in 6th gear, switch to 5th gear, or even down to 4th gear if on a hill. Keep your revs up over 2000, back off the throttle, slow down, make sure you are using tow haul. I had been pulling my 5th wheel on I-80 in Wyoming somewhere west of Laramie, cool day, wind blowing with me, and my CTS2 temp was 235, I was very concerned, but I just slowed down a little, downshifted, kept going, temp didn't spike any further, and eventually the fan locked up and temps came down quickly. I was so surprised that the conditions would ever cause the engine coolant to get that hot, but it did.

You replaced a lot of parts, I hope you cleaned everything in front of the radiator.

When you get to 230, and is that from the gauge or from some other source? , does the fan do a full lockup, sounds like a roar from the fan?? If it does, and the engine cools down, you're probably OK. Might try changing to a 20lb coolant recovery tank cap for a little higher boiling point.
 

·
Registered
Joined
·
3 Posts
Discussion Starter #3
It is probably normal, depending on the conditions under which it occurs. Temperature, altitude, speed, throttle position, boost, torque converter lockup, etc. The more power needed, the more heat the engine produces and the higher the coolant temp will go. If you are towing in 6th gear, switch to 5th gear, or even down to 4th gear if on a hill. Keep your revs up over 2000, back off the throttle, slow down, make sure you are using tow haul. I had been pulling my 5th wheel on I-80 in Wyoming somewhere west of Laramie, cool day, wind blowing with me, and my CTS2 temp was 235, I was very concerned, but I just slowed down a little, downshifted, kept going, temp didn't spike any further, and eventually the fan locked up and temps came down quickly. I was so surprised that the conditions would ever cause the engine coolant to get that hot, but it did.

You replaced a lot of parts, I hope you cleaned everything in front of the radiator.

When you get to 230, and is that from the gauge or from some other source? , does the fan do a full lockup, sounds like a roar from the fan?? If it does, and the engine cools down, you're probably OK. Might try changing to a 20lb coolant recovery tank cap for a little higher boiling point.
It was from my edge. The gauge on the dash isn’t very accurate. I am pulling across the desert 115-120 ambient air temp. I usually have to drop to 4th gear about 50mph. Trans temp runs about 205. As soon as I crest the top of the hills temps drop down to under 200.
 

·
Premium Member
Joined
·
327 Posts
It was from my edge. The gauge on the dash isn’t very accurate. I am pulling across the desert 115-120 ambient air temp. I usually have to drop to 4th gear about 50mph. Trans temp runs about 205. As soon as I crest the top of the hills temps drop down to under 200.
Then what you’re seeing is normal.
 
1 - 4 of 4 Posts
Top