Hi guy's !



I just had a few minutes free time last night to get one head off my 1991 6.2.

First , one of the pre combustion cup fell off by it self ??? Dont know if there are over sized ones available .... or if it dosent realy matter if it isnt press fit....


Second; there is only 3 valve seals on three exaust valves ???

Three is not normal i know, but why only on the exaust valves ??
arent thew suppost to be on the intake valves to keep oil from being sucked from up there ?? ....

And i would put some on exaust to to keep back pressure from exaust to get up in the valve covers.....


Third; valve seems are pickered or kind of rough, and they leak when i throw compressed air in the exaust EX:pt some liquid soap on the valve while the head is facing up, and there are bubles all around the valve when i put the air in the exaust port, the springs are all 2.080" free lengh, and the inner spring is ok to....

I posted a couple weeks ago for a bad idle, with louder bangs comming fron one side of my exaust pipe, and i changed all 4 injectors on that side and it didnt change nothing, so i came with the conclusion that it was a bad exaust valve or spring that would let a part of the explosion come out while the piston is going down...

I think i was pretty close of an issue by taking off the valve cover to inspect under there...

I didnt see anything anormal , but when i put 100psi in the glow plug hole, there is a draft of air comming out of the tail pipe ???

Dosent sound normal to me any way...

So.....


What are your thoughts for all these questions,


Your advice is realy apreciated !!!

Thanks.

As far as I know, which could be nothing, the precup shouldn't fall out so that to me means the head is junk.

The other stuff I know, your heads are worn out, you need a valve job or new valves or new heads based on the above. Some engines don't run exhaust valve seals and theres no pressure there, its all suction. If you only have 3, the other one(s) probably got old and broke off and are sitting in the pan.