Engine/Transmission (1994 - 1998) Turbo cooldown

[EWalshak]

Can anyone shed some light on the cooldown issue?Is it relevant for a stock truck?Any issight would be appreciated. Thanks

 

[TBartlett1]

Stock engines can get very hot also.

My 1990 is completely stock with no guages but when I work it hard I give it a 5 minute idle to cool. Normal running no but if worked yes.

It has 300k & never been apart except to replace the injection pump seals when low sulfer fuel came to town.

 

[BHanna]

I always wait until my EGTs get down to 350 to shut down and unless I coast downhill to a parking space it usually takes me about 30 seconds after normal in-town driving. If you've been climbing a hill or towing, it may take longer but I haven't had mine take longer than a couple minutes. One note, I turn the A/C off to make the cool down happen faster. It can take a while for EGT to get down to 350 with the compressor running.

I have a 3rd gen but I'd imagine they're similar as far as this goes.

 

[HBarlow]

Your owner's manual provided brief and clear instructions on turbo cooldown. The manual advises that if you are running at full load, full power on the interstate allow five minutes before shut down. Running around town at low speeds, low power, unloaded, use one minute. Other variations on power and load require a period between one and five minutes. The cooldown time recommendation corresponds with the time it takes a stock engine to cool to 350* to 400*.

The reason for exhaust temp/turbo cooldown is to prevent coking of oil in the turbo bearings. The turbo may continue to spin for a period of time after shutdown but oil flow stops when the engine is shutoff. Heat soak from a very hot turbo could coke the oil and damage turbo bearings.

 

[AClayton]

I heard from several members that when I've asked this question that 400 is a 'SAFE' mark. '350' is a better number to settle for and with upgraded injectors and 'magic boxes' and all the other stuff many of us add,it is 'YOUR' responsibility to cool the turbo and engine down. And without gauges on a modded truck,you are sincerely taking chances!



I added all the hardware that makes the Cummins smoke and create egt concerns... I have since added a small set of twin turbos that puts me right back to stock conditions. I added a larger intercooler to aid in towing prowess and turbo spool. Basically,I have a stock truck with very similar,if not better than stock,cooling and towing qualities. I also added a turbo-timer to help save time sitting in someone else's driveway or a parking lot,waiting for my turbo to cool.



May have over-answered the question here,but as mentioned in previous posts,it is routinely important to monitor and/or respect proper cool-down procedure..... stock and more importantly,modified.



Alan

 

[Harlacher]

"I added all the hardware that makes the Cummins smoke and create egt concerns... I have since added a small set of twin turbos that puts me right back to stock conditions. I added a larger intercooler to aid in towing prowess and turbo spool. Basically,I have a stock truck with very similar,if not better than stock,cooling and towing qualities. I also added a turbo-timer to help save time sitting in someone else's driveway or a parking lot,waiting for my turbo to cool. "



Alan,



I wish they came stock with all the great stuff you have added. Twin Turbos is my next investment along with the shut-down timer. I hate sitting there with the door open, one foot out of it waiting for temps to drop. My son just put a timer in his and he thinks he so cool when he comes over. Makes a point of jumping right out with the truck still running with a big smile directed at me. I know that it is cost prohibited to build a stock with the mods you have on yours but it sure would be nice.



Paul

 

[AClayton]

Thanks Paul... . it does come at a cost though. The better half only knows a small percentive of what has been actually spent... . I fear if she knew everything,I would be seeing Judge Joe Brown or Judy:-laf



Get a turbo timer from Geno's... . I believe it was a hair over the $100 mark. Saves a lot of time and the looks you get from people when you get out of the truck and they visually see you hit the door-locker,is Priceless!!







Alan

 

[EWalshak]

Man !!!!You guys are a wealth of info!!!I've just purchased EGT guages for both my CTD and my Suburban. That cooldown timer is on my list of things to get. Thanks again.