After taking my head off to change my gasket and timing belt (timing belt snapped) I looked under the head thinking I would find bent valves. The valves were not bent at all but there were divets in the pistons from the vavles hitting them when the belt snapped.

Is it ok to drive a car with divets in the pistons. Will it cause problems for me? If so what are they?

Thanks,

Dean.

I would have a profesional check out the valves and have them vacume tested id bet they are bent and you cannot see it...

the divets in the piston wont hurt much, if the divets are big enough to make burrs you can deburr them with a file and make other things...

are these stock or forged pistons? as long as you didn't crack the piston you should be fine, although you could have weakened the pistons and if boost is in the future i would think about forged units cause the cast units will more then likly fail now...

Bill

one easy way to check if your valves are bent is to lay the head on it's side ( intake or exhaust port facing up, whichever you are checking)and pour a cup of water in that port, fill it up but try not to spill.

If you get immediate leakage past the valve seat area, the valves are bent in that port , don't reuse them.

if you can let the water sit in the port and does not leak at all in 5 minute period, they are fine.

If they take a while to leak thru , 5 minutes or more , they are still ok....... as long as it is a mere TRICKLE, like a DROP or two and not the whole content.

Dump the water out, blow dry it with compressed air and spray with WD-40.

Must use water though , becasue if there is a leak , water will find it and get thru.

Motor oil or WD-40 because of the molecular attraction to metal and vicousity compared to water, might give you a false seal.

that sounds like a pretty sound idea, im not 100% sold on it but it should work...

Bill

If there are divets in the pistons, the valves are bent, period. Don't argue, don't try to save them, just buy some new ones and move on. As far as the pistons go, If all you need is for the car to get back on the road, polish the divets out with some sandpaper to make them smooth, check the piston for cracks and other damage, and go.. If you expect it to perform, and want the most out of it, just get new stock pistons.

Yeah the guy at the machine shop suposedly did a vacuum test on my head but I don't know if I trust this guy. This is really weird though because as deep as these divets are you would think that the valves would be noticebly bent. The divets are so deep that it seems like if I were to sand them down it would drop my compression. Of course I've never really dealt with shit like this before so I don't really know.

Is it possible that this vehicle had this problem before and the previous owner or his mechanic just replaced the valves and not the pistons?

Thanks for all the info I really apreciate it,

Dean.

well if thats the case then there would be carbn buildup in the divets and it could be challenging to see the divets...

post pics and that will help us...

if it made these big divets the valves would have to be bent atleast a couple...
Bill

This is probably much simpler than I'm making it, but unfortunatly I don't have a digital cam. The first and the last piston have carbon build up on the pistons but the middle two seem pretty clear.

I hope I don't need pistons. I was just looking at howell and they're like 500 bucks.

have you had problems with your timing belt before?...

no, no problems. I bought the car with like 65,000 miles on it and it has like 130 now, so maybe the last owner did.

I had my timing belt changed at 65k and the autoshop, that did it didnt change out the idle tensioners, and the belt came loose. skipped cogs, and WHAM! 1400 dollars later. (oh yeah they denied responsibility, this all happening within 3000k) but the point being that they did a vacumm check on my engine and they though I got lucky and missed the valves..I started to drive the car all seemed fine. well the valves spin when they get hit by the cams and all of a sudden my car started shitting out on me. took it back and they checked it again. I had bent valves, and they put the valves on a grinder to show where they had been bent. I think I still have some if you want a few pics them x(

Well, like I stated earlier, the water method is pretty safe, I also double check with a leakdown tester.
If anybody has a head that was recently fixed or or ported , try the water test and I guarantee you will be surpised by the results.

If you want to make make sure, before you go to all the trouble of putting everything back together and finding out that the vavles were bent, here is another thing you can do..........

Put the head on the block with out the cams or plugs, use a cylinder leakdown tester with the heade torqued down to 40 ft Lbs.
If you have a too much leakage, you can remove the head and redo the valves that were bent, that should help the most cautious owner ever.



sorry for the big pic , but it is an old pic I had on my website.

This is a pic of my cylinder head leakdown test when I installed one of my P&P heads on my own car, if you can read the dial it is around 5% leakage, needless to say I went ahead and installed it , this head too also passed the water test.