Turbos and UOA

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Originally Posted By: DoubleWasp
Are turbochargers a factor in the wear metal results in a UOA, or are they just basically shedding so little (properly working) that it does not matter?


The bearings in a turbo are really small, and they can't wear very much at all before they are toast.

So, yes: "just shedding so little (properly working) that it does not matter?" is correct.

I have seen turbos with 5,000+ hours of operation show *NO* noticeable or measurable wear.
That's pretty good (assuming 5,000 x 60 mph = 300,000 miles equivalent)

Just today I talked to a trucker with a 2001 Freightliner with 1.6 million on the clock,
He says he replaced the original turbo at 1.2 million miles (60 Series Detroit)
100% Mobil Delvac 15W-40 it's entire life.
 
Originally Posted By: Linctex
Originally Posted By: DoubleWasp
Are turbochargers a factor in the wear metal results in a UOA, or are they just basically shedding so little (properly working) that it does not matter?


The bearings in a turbo are really small, and they can't wear very much at all before they are toast.

So, yes: "just shedding so little (properly working) that it does not matter?" is correct.

I have seen turbos with 5,000+ hours of operation show *NO* noticeable or measurable wear.
That's pretty good (assuming 5,000 x 60 mph = 300,000 miles equivalent)

Just today I talked to a trucker with a 2001 Freightliner with 1.6 million on the clock,
He says he replaced the original turbo at 1.2 million miles (60 Series Detroit)
100% Mobil Delvac 15W-40 it's entire life.



Are there major differences between diesel turbos and gas turbos? Many people seem to think that they will be the first thing to go on a turbo engine. I have always wondered how turbochargers on turbo diesels go much longer than gas turbos - I'm assuming that they do last longer since I do not hear complaints about diesels requiring turbocharger replacements.
 
A properly lubricated and cooled turbo will last just as long as any other bearing in the engine. Lifespan is compromised in several ways:
Low oil kills the bearing
Insufficient cooling lets the oil in the bearing coke after shutoff, next run sees oil starvation and kills the bearing
Improper oil choice promotes coking in the bearing
Remapping or chipping the ECU for more boost puts more heat into the bearing accelerating wear

There used to be a mantra in the early days of mass turbocharging, they said "spool, then cool" and saw good life.
People who are in a rush to go shopping/get home etc who cut the ignition as soon as they reach their destination without sitting idle for a while to let the turbo cool see one of the above listed problems.

Good maintenance and operating procedure is key to good longevity, and Id guess the big-mileage turbo diesels in America are truck drivers who know how to operate their machinery, where a lot of petrol turbos are consumer items driven by people who don't know or care (generalisation, I know you're not all like that)
 
Originally Posted By: Olas
Good maintenance and operating procedure is key to good longevity, and Id guess the big-mileage turbo diesels in America are truck drivers who know how to operate their machinery, where a lot of petrol turbos are consumer items driven by people who don't know or care (generalisation, I know you're not all like that)



This.
 
Most over the rood big trucks are driven a a fairly constant speed. Their turbos are designed for high efficiency at a constant speed. The gas engine turbo is small to reduce speedup time for quick acceleration. I think that is why Diesel turbos last much longer than car turbos. ed
 
Diesel engines also tend to run lower exhaust gas temperature compared to boosted petrol engines.

That said a modern turbo can last a long time with water cooling (most of them), quality oil, staying on top of OCI, and letting them idle to cool down after hard driving.

I'll be checking the bearings for play in the spring, but my car has the original turbo after 184k and it still works just fine. No noises, unusual oil consumption,or other common signs of impending failure.
 
Originally Posted By: VeryNoisyPoet
That said a modern turbo can last a long time with water cooling (most of them), quality oil, staying on top of OCI, and letting them idle to cool down after hard driving.

I'll be checking the bearings for play in the spring, but my car has the original turbo after 184k and it still works just fine. No noises, unusual oil consumption,or other common signs of impending failure.

It'll be fine. The oil cooled (only) turbo in my '86 Volvo 740 Turbo lasted a long time. Still going strong after 285,000 Km and 18 years. I then sold it to friends who drove it for 5 more years and the turbo was still fine.

Oil was not as good as today's (always conventional, often Pennzoil PZL Turbo) but changed every 3 months. And letting the turbo cool after hard driving.
 
Originally Posted By: Eddie
Most over the rood big trucks are driven a a fairly constant speed. Their turbos are designed for high efficiency at a constant speed. The gas engine turbo is small to reduce speedup time for quick acceleration. I think that is why Diesel turbos last much longer than car turbos. ed
I could easily get the turbo temps to the red line on the pyrometer on the class 8 trucks which was 1200*f .
 
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