I've just joined the forum today, but have been scanning the various threads for info on white smoke, injectors, and fuel pressure regulators.

My 02 Duramax [LB7, I presume] currently has 182K miles, within the new 200K warranty limit, but several months over the 7 year limit for replacing the injectors. In any case, the injectors were replaced under warranty at 102K. [Would be interested to know if anyone has had a second injector replacement under warranty?]

It was smokin' back at 102 and is smokin' again now. I presumed it might be the injectors and reluctantly drove into the local dealership, Lawley's in Sierra Vista, AZ. They got a P 0089 diagnostic code which indicated a bad fuel pressure regulator which they changed [for a mere $1032 and change] and my Duramax still smokes!

Back for more tests... the injectors were found to be "within tolerance," i.e., GM would not replace them IF my truck were still under warranty. Nonetheless, fuel was found in the crankcase; part of the $1032 was for an oil change, as well as an air filter replacement. Oddly enough the dealer didn't change the fuel filter, though I found an article on this site that says the fuel filter should be checked/replaced for any DTC related to fuel rail pressure.

Late last week the dealership -- which seems to be "working with me"-- did a compression check w/o charge. Passenger side bank: 285/280/282/280 Driver side bank: 260/250/270/280. Thus, driver side is low and uneven. I think this is bad news, but not sure just HOW bad.

Sorry for this long, long post...

So now what? Any idea where the white smoke might be coming from? The only major repair other than the injector replacement at 102K was a water pump replacement 2,000 miles back. It was leaking from a weep hole, indicating worn seals...? The coolant is holding steady.

Any advice out there? I don't want to replace the injectors and find it still smokes. Is there no definitive test to determine the reason for the smoking? I've experienced no loss in power, but the smoke screen is embarrassing and not doing the environment any good.

In any case, what's the "life expectancy" of a diesel engine. Someone suggest to me that it should last to 300K and beyond. Yes? No? Maybe...

Any and all advice appreciated.