What the hell would cause this????

[95formula383lt1]

A buddy of mine bought a 2000 caviler 2.2 4cyl 110,000 miles. He bought it super cheap had no compression in 1 cyl figured it was ether valve seals or head gasket maybe rings. So tore it down got the head off flipped it over an found a valve was completely cracked. No damage to the piston or signs of contact, car ran good but rough at idle and anything off idle ran perfect. Any ideas on what happened? he ordered a new valve gonna install it an throw it back together.

http://i619.photobucket.com/albums/tt273/95fomula383lt1/1007101314b.jpg

http://i619.photobucket.com/albums/tt273/95fomula383lt1/1007101314a.jpg

[Tarheel'Z']

anything in the oil pan?

[95formula383lt1]

Not that i know of he didnt pull it off or drain the oil yet. im not sure how it could be since it was a exhaust valve and no cyl damage so nothing got passed the piston an into the crank case.

[gregrob]

I bet someone tried to run it on E85. Those valves been HOT

[95formula383lt1]

yea i think all the exhaust valves have been hurt imo. hes only going to replace the one.

[razor02097]

That motor was run for a long time on that bum valve... just look at that erosion! :face_shocked:

Hopefully the new valve can be lapped in without having to machine the valve seat...

[95formula383lt1]

im thinking he should have the seat re done for sure, cuz def was run a long time like that.

[BlueBottleZ]

Detonation will cause that. I was told once that it takes 5 sec of continuous detonation (bad fuel, timing, stuck or non functioning egr valve) to glow an exhaust valve cherry red! I would def make sure the egr valve passage is clean and the valve itself is operating properly!

[BlueBottleZ]

WOW! I just ckd the date this was originally posted Im WAY BEHIND!!!!

[popo8]

WOW! I just ckd the date this was originally posted Im WAY BEHIND!!!!


Its all good, just glad to see your posting.

[Fixxer99TA]

Still an interesting topic, thats one hell of a burnt valve for sure :D