as some of u know i had an 09 yukon denali with heads and cam.. stock bottom end, drove it everyday for 2 years did 40k miles on it , always babied it just do a couple WOT runs when the temps arnt 110+ outside.. it was tuned by some idiot 11.0-11.2 afr WOT and very low timing, then i got it tuned through a guy in the US he leaned it out and increased timing by atleast 7 degrees. so we opened up the engine today cause im doing forged pistons and rods planning on going boost.. a few things i found.. the engine was running perfectly fine the only downside is that its using alot of oil probably because of the way it was tuned glad the cylinder was still fine the oil scraper was toast lol

dual livernois springs 690lift the inner top part was broken only very odd



cam bearing im using the durabond ones now



crankshaft journal




any idea what caused those scratches on the cam journal and bearing? any recommendations about the crank? should i go with a forged one or just keep this and change the bearings

 

Did it ever run low on oil?

 

Yeah once, i never knew it was using up oil when i checked the dipstick i found nothing on it there was no weird engine sound or indicator on the dash about the oil but since that day i always checked the oil level

 

It doesn't matter if it's only like 5 minutes with it that low on oil it will damage parts. If u think about how many rotations take place in only a few minutes. So unless u found metal fragments (small like dust size)in the oil all sources would point to running low in oil doing the damage. Either way that sucks and I hope u the best with the rebuild.

 

Low oil level won't damage things, low oil pressure will. The dash will warn you of low oil level long before it gets to the point of starving the pump.

 

If you are running low on oil an you abuse the motor you will actually starve the pump/parts. I know of a guy with that same issue and his 6.2 that was ran low on oil. Yet still ran it even though it showed 40psi. It ate up the cam, an spun main bearings.

 

starvation issues

 

Apparently 6.2s need oil! Mine usually showed 40-60# and one day it dropped down to 10 in the middle of a turn and then came back up. Ever since then I had problems with it making noises. Now its broke! Spun a rod bearing.

 

Those of you with low oil issues aren't getting warning lights or anything indicating low oil?
I wonder if the oul pan sensors on some of the 6.2's aren't sensitive enough to provide enough warning before damage is done.

 

GenIV oil pans dont have low oil sensors :jerkit:
GM fail