My Tahoe I just got two months ago seems to be getting sicker. I took it to the only hybrid mechanic in town (except dealer) and replaced coil, spark and wire. Code popped up again. Mechanic said I had only 120psi in cylinder 8 so I put about a half can of Seafoam in the crank case to clean the lifters and valves and it ran beautifully for about three days. Still wasn't recovering mpg, but it was getting better and was certainly smoother. Then the code came up again.

At my wits end. Batteries all check out fine. My 12v battery from 11 - 14v. Hybrid getting full 300v.

Oh, and oil pressure at 60 psi!

 

Have you looked at all the plugs and done compression on all cylinders?

 

No. Not getting any other bad misfires. It'll probably be the next step before going to the dealer. All my OBDII data points to Cylinder #8.

I am a bit confused at why my oil pressure is so high cold. When it warms up, it's back to around 40 psi.

 

Well, perhaps I've received the worst possible news I could for my vehicle. Three independent shops all feel that it's probably a bad lifter or worn cam. Dealership wants $5,100 just to get to that part. Replacing the whole dang engine will cost about $9,100. Are there any other options?

 

A good used engine from a wrecked 2010 or newer. HOWEVER, several parts like fuel injectors and rails need to be swapped out from old engine.

 

OK - so rebuilts are being quoted by non-dealerships at $7400. I can find the engine (minimal warranty, using existing accessories) for the LOWEST at around $3k. Quoted labor time is 22 hours. Oh, and $1500 for the gasket, lifter kit. $750 for a camshaft...

Sound about right?

Verdict seems to be that the lifter on Cylinder 8 got stuck and that the camshaft got worn down.

 

You want a 2010 or newer "donor" or 100% new.

 

This is a common problem on these engines gm claims it isn't of course. My 6.0 has burned oil from the get go just did plugs and wires bc they plugs were foul terribly from blow by from the pcv valve. New RHS valve cover designed to help with this problem.

 

As much as I would like to do it "right", I simply can't afford it. I have a mechanic who says he can replace the camshaft and the offending lifters for $1,500. I feel like I really have no choice. Sure, a rebuilt long block would be a great solution. Maybe when I get this thing paid off. Until then, I'm going to take the gamble and hope he can do it. He's worked on this car before - he knows what he's up against.

I hope.

But - does it **have** to be the LFA? Will a steel block 6.0L (ie: LS2) work?

 

Not sure about iron block. Doubt it is compatible