Has anyone heard of the #4 cam bearing turning and not letting oil flow to the turbo? I read this in a tech colum for "MOTOR" Magazine June issue. It seems that there were some 2002 - 2004 Dmax Vin #1 & 2 that were comming in with fried turbos. GM found that the #4 cam bearing that oils the turbo was turning ,"spinning", and blocking the oil port to the turbo. GM supposidly issued a tech tip ,to pull the oil tube and look in to see if the cam bearing had spun. If it had the only recourse was to tear down and install a reman engine. If not Replace turbo.
My question is what is GM doing about this are they being proactive or reactive. My Dmax is just over a year old and I have called the dealer and they will say is "we haven't heard any thing about it and there are no recalls....". Any info on this subject would be appreciated.

FYI, I just checked online and there were no recalls for my DMax. There may be some tech bulletins, though.

Dave
05 Silverado 2500HD Crew Cab

There is a service tip for the techs to check this when they have a turbo failure. This was done due to a few spun/moved bearings. Bearings have spun ever since engines were put together, it's not a problem but yes some have spun/moved. GM is just keeping the techs informed as to what to look for and if the truck has less than 100,000 miles GM foots the bill for a complete engine.

Thanks for the info. I have a GM Tech that is still working checking this also. A friend of mine that just retired from GM is having his tech friend checking into this.
I enjoy the forum and will continue to support it.

P.S. Before I bought my DMAX I contacted my friend who put me in touch with the dyno guys at GM. At that time Jan 2004. they had a DMAX on the dyno that had been there for aprox 4 months. It had 370,000 miles on it and had only been stopped for routine maintainence. NO PROBLEMS !!!
That convinced me right there.

Thanks guys Keep on MAXIN.

The environment on a dyno CAN be very controllable, ie; load, room temperature, plenty of cooling, etc. I would expect a completely controllable environment from R&D. It may not be a good indicator of some real world environments it they did not specifically test for it. Dyno's are only a tool! In 04' it may have also been a LB7.

What is the LB7? not up on the latest lingo for the new fangled vehicles. The dyno test was started in Jan. 2004 and ws still running at last check when my friends buddy retired from GM. I was wrong it had 570,000 miles on it and it was controlled as they say in a "semi mid eastern environment test"?
That is what I was told.

Lb7 is the first generation 6.6 duramax engine.... I forgot the exact month in 04' when it changed, but the 2004.5 6.6 Second Generation Duramax engines are called LLY's. They changed horsepower/torque and some other stuff.