idle down to cool turbo

it seemed to me you are not only are letting it 'cool' but giving it time to spool down or slow down so when the engine is shut down and the oil stops flowing the turbo is no still spinning at the speed it was running down the road.

 

I guess a person could find anything to substantiate his claims if they look hard enough.

A turbo has NO bearings, in fact there isn't a bearing made that spin 100,000 rpms. The turbo has a shaft and a bushing... the shaft is protected by a film of oil that surrounds the shaft within the bushing.

You will damage the shaft of the turbo if you rev up and turn off the engine as the turbo will be spinning without oil to isolate the turbo shaft from the bushing.

Oils are tougher then they were even 10 yrs ago, but considering that a turbo failure could take out your engine, is there any reason why you can't let your engine cool down for a few mins ?

 

some turbo's have bearings. turbonetics even has ceramic coated bearings in the hi end turbos.

 

That is quite the impressive turbo, but what does this product have to do with everyday diesel truck turbo's ? They don't even offer a turbo for commercial application that I could find.

 

Not all bearings have needles or balls. Yes that bushing is a bearing.


Also as oil gets loaded up with soot how does that affect it. If you run more than 300hrs or 15000 miles between oil changes you aren't doing the turbo bearing any favor by not cooling it down.


Clean oil under lab conditions might not coke. The real world is not in a lab.

 

The turbo's have a pair of bushings, they are about 5/8 of an inch and have holes in the middle the oil goes into the middle and out the ends. The bushings turn freely, in the housings and on the shaft. The shaft floats on a bath of oil. Turbo's spin at 140,000 RPM. That is why if you have waist gate turbo and clamp off the hose the warranty is void, even a mark on the hose it has ever been bent. Not returning the old hose and damage is good enough to void it.
Cat is especially hard on turbo cores.

 

I am all for embracing new technologies.
I just cant believe there is any turbo that will last if you cut the engine immediately after a long pull.
The exhaust shell can glow it gets so hot.

 

I had my truck shut off after 6 hours nonstop driving at hywy speeds turned key off at 1500 rpm's. that was 5 years ago. still original turbo 17 years old. over 1.4 mil miles still going strong. now as far as why I had truck turned off was not my intention. while going south thru Louisville ky years ago on i-65 traffic in my lane came to an unexpected stop. I got on my brakes & one of my 1/2 gal water bottles rolled from the sleeper & hit the key & turned the ignition off.

 

#### it clean those 100 or so water bottles out and you wont have that problem any more.

 

I have also had to turn off in an emergency and I only ever had one turbo fail.
That was due to a rag left in the intake , not due to the odd immediate shut off.
I'm talking about habitually cutting the engine when EGT are hot.