This morning I took the evo out for a drive to the shopping center. When I got back in the car after shopping I tried to start the car and I heard some loud pops while cranking and it wouldn't start. I took the timing cover off and noticed the timing had skipped because there was a good bit of play on one side.

My question is - what is the proper procedure for diagnosing valve damage? Should the head be removed and inspected, or would a passing leakdown test with a new timing belt service be suitable?

 

you have valve damage 100%, it is an interference engine.. you probably also have valve guide damage (ask me how I know.. ) If you are lucky you did not break a valve as this will lead to more head and block damage..

 

best thing is to get boroscope trough the plug holes and see if there is broken valves evident inside.. but I would take the head off (after confirming that the timing is off)

 

Okay thanks I'll take the head off and inspect, sounds like the safest course of action. How did you diagnose valve guide damage?

 

the guides like to crack in the port... it doesnt have to happen but happened to me..

what you can do without pulling the head off is to take cams out and measure valve stem tip height.. those that are lower are bent...

I would avoid cranking the engine over anymore as it risks breaking off a valve head..

 

Dont jump the gun.
Reset timing and do compression test.
Leak down test if compression is low.

I dont think you bent valves. Dont just start tearing it down without resetting the timing. Also why it jumped. Failed tensioner?

 

if you want to try a new timing belt first, then please take the cams out and measure the valve height first, and take a look inside the cylincers with a boroscope.. you do not want to crank an engine with bent valves..

 

Just taking a lunch break now. I've got everything off except the intake manifold at this point, so I think I'll just keep on with removing the head. I've got an FP red and I've been thinking about getting a built shortblock for a while now so I can tunr up the boot. Maybe I'll just take this opportunity and ship it off for a build.

I've been waiting to have the head removed before I try to identify a point of failure in the timing system just because the clearance in there is such a pain in the ***. However there's so much slack in the belt I expect the tensioner must have given up? I'll find out and post here

Thanks for the input guys.

 

So if you get the head off and find the valves to be ok. Your cool with all the wasted time?

 

Yes. If I get the head off and find there's no damage whatsoever, I'm fine with that.

 

I guess....

A new head gasket and valve seals wont hurt anyway....

 

I'm confused - why are you acting like I'm asking you to remove the head for me?

 

Ill paypal you $20 the valves are not bent. How bout that

 

This is a first for me. I've never had someone be so adversarial towards me about taking my own car apart - especially after thanking them. Maybe you've done this a hundred times and have never seen valve damage. Maybe there won't be damage. I don't care. I have plenty of time and I would like to learn how to do it. I opened this thread for advice and to share with others what I find, but god damn.

 

Your car and time. Do as you please. Just asked for opinions and you got some. And mine is dont take it apart until you know its got damage.

Dont fix if it aint broke.

Your the one asking for advice.

Might as well drop your trans,tcase and diff and tear them down for inspection.