I just purchased a 2009 Tahoe with 4.8 liter engine. Current mileage is about 128000 miles just received a phone call from the dealership that it needs an engine replacement low compression on cylinders 1 3 and 5. Is it reasonable to ask why an engine would have a failure or catastrophic failure at 128000 miles?

 

That all depends on how it was treated for those 128,000 miles. Was regular maintenance done on it such as regular oil and filter changes?

 

yes regular maintenance was performed.the engine just died going down the highway.

 

Currently I am tearing down the engine. The dealer wanted 7000 for a new engine. Should be pulling the heads tomorrow. The cam is turning because the rockers are moving when the engine is spun over. These new engines are easy to work on.
The engine did not knock or make any noise of any type when it died. Any ideas on what could be a fix?

 

u should determine that before tear down. do wet and dry compression tests then cylinder leakage tests ...its can be:
headgasket
rings
valve train related

 

I wonder why a certified Chevrolet technician told me I needed an engine? He did a compression check. Once I pull the heads I will see what the extent of the damage. The Tahoe does not blow oil burn oil. But to have a severe drop in compression. Something is wrong.

 

phone the dealership and ask what was caused the low compression. Why do you need a new engine; was coolant in the oil.

nothing worse than tearing something down and not finding the source of the problem. that is why you test before teardown.

 

Found some of the issues causing no compression. Bent intake push rods. Removing heads to look at damage to pistons. Sending heads out for repair Monday.

 

I have a question for the techs. Does the engine have a crankcase pressure sensor?

 

bump no response nice