I'm a little confused about the turbo cool down thing. I installed an EGT gauge and I know that you need to wait untill 300 degrees before shutdown. As I understand it has to do with bearings in the turbo and the fact that they need to be below a certain temp. before shutdown. By running the engine at idle the temp comes down and then it's ok to shutdown. What causes the cool down of the turbo and why does running it at idle lower the temp. Would like a complete and factual understanding just so that I know once and for all.

 

Idling produces the least-hot flow of exhaust through the turbo while maintaining the flow of oil which also cools the bearings. Therefore, if the turbo is above that temp, it will cool down while idling.

 

So oil will flow thru the turbo which removes heat from the bearings while the engine is running and the engine must run in order for the oil to flow and while idleing the exhaust gasses are the lowest they can be.<br><br>I was a little unsure about the oil flow through the turbo because I was told by someone who has been driving a CTD a loooong time that oil does not flow through the turbo and that had me perplexed.<br><br>Thanks for the info.

 

Pull the oil line off the bottom of the turbo and see how long it takes for the oil in the crankcase to deplete with the engine running. Amazingly enough with all the extra guages we put on nobody runs a post turbo temp guage for the oil, this could prove to be interesting. PK