Today while idling in traffic, the engine developed a miss and stalled. It started immediately, but was rougher than usual and would not idle with the air conditoner on. I was 100 miles from home, so I drove it and it had a funny deep sound and lacked low end power. Gas mileage dropped to 12 mpg. Normal is about 25mpg.

My first thought was that my opti finally took a crap. Got home, changed the plugs and started it up again. Still running like crap. I detected a small tapping noise that I did not recognize. After three hours of messing with it, I took a compression test on the cylinder that had a very wet plug (with gas). No compression buiild up at all.

Removed the passenger side valve cover and found this.

BROKEN VALVE SPRING AND DAMAGED KEEPER



BENT EXHAUST VALVE AND MISSING ONE VALVE STEM LOCK


ONE BENT PUSHROD




My question is.....could that missing valve stem lock have done some engine damage? Could the bent valve have done some damage? I plan to overhaul the engine next winter. . . . .and stroke it. Should I just fix that head, or could I get away with some performance bolt-ons that would work good with the stroker next year.

You might ask....well how did this happen? It happened after I removed the factory rev limiter using a hypertech programmer. I know I have banged into 6500 rpms a few times. . . especially last weekend. Any direction would help. My budget is limited right now to 1k.

 

That valve "hit" something to bend the stem, IMO. That means there could be damage to the piston. I don't think you will know the story till you pull the head and do some inspection. Good luck.

Was that with OEM valve springs and keepers??

 

No, they were the springs that came with the GM hot cam kit. now that I think about it, I am going to change all of the springs if I go the route of keeping these heads.

Saw a pair rebuilt Aluminum Lt-1 heads for 400 bucks on ebay. That may be the way to go.

 

Souds like a good plan.

BTW, did you install new keepers with those new springs??
If not do it during the repair.

If you like to push the rev limit maybe it'w worth a set of Ti retainers and 10deg locks?? If those springs are the tapered cone-shaprd style the Ti won't be nearls as expensive as the full size ones for my stock style springs...

 

Brand new keepers. I remembered that I downshifted accidently on Saturday to such a degree that the back wheels completely stopped. I thought I was going to break a driveshaft. Car ran fine though on Sunday. Drove it 50 miles on Sunday no problems whatsoever.

BTW, did you install new keepers with those new springs??
If not do it during the repair.[/QUOTE]

 

I have one question which I do not mean to hijack your thread with. Back in April I also broke an exhaust valve spring on my A4 92. I must have got lucky as a **** house rat because I drove mine for 15 miles and I had no other damage but a broken spring. This normal?