I've been trying to pinpoint a noise that I hear under WOT, but no load. I got this on leakdown:
1-15%-OK
2-15%-OK
3-15%-OK
4-80%-BAD

I pulled the turbo/manifold and it is leaking from the exhaust port. So, before I pull the head, I am probably looking at a bent valve, correct?

I have to admit it was quite a while since I last did the valve adjustment. 170K on the stock block/head currently. Last adjustment was at 140K.

Are replacing the valves as easy as it is on a chevy v8? Compress the springs, remove the retainers, pull the valve, etc...
Thanks for any input.

 

bent or burned. burning exhaust valves is common on oil burning not adjusted engines. a chip missing from one of the exhaust valves happens all the time around 170k. rings are probably fried too which is why you have 15% on the others. new rings, a hone, a valve grind, valve seals and 8 new exhaust valves should have you going for quite awhile longer.

 

Thanks for the response. I'm going to check the pistons while I have the head off. If they look bad, then time for new rods and pistons, as well as valves and springs. It was about time for the stock block to give out anyway. The rings might also be ok, I had a new civic engine with about the same readings on my gauge, where 10-40% is in the green, 40-60% orange and >60% red.

 

15% is excessive for a healthy engine. however. it could be valves. you're correct about that. it's just these engines are famous for eating rings. when you consider OE rings are $100 and a hone at the shop is $50. even if you do nothing else it's $150 well spent down there.

 

Here are the valves, #4 and #3 exhaust are pretty corroded:

#4 exhaust valves are not even seating.


and the plugs (10k+ on these plugs)


I was looking at some Brian Crower stock size valves (intake and exhaust)and springs w/ steel retainers. Other brands I was checking are Supertech and Ferrea. I don't need to rev out to 10K or run an agressive cam. Not really sure on which direction to go there.

I am assuming I will need to take the head for machining work to get the valves to seat properly again. Does anyone know how much that costs? Or should pull the valves out first and look at the damage myself. Sorry, I don't know much about valve work. :D

 

Anyone? I know there are some valvetrain guru's out there

 

yes, the head does have to get machine work, and i would replace the valves, and check the valve guides, theres alot of measuring and calculation involved with these sorts of tricky problems, your plugs and cylinder head look pretty fouled up there too, running rich it would seem

 

appears rich but isn't, the ash fouling is from oil burning. when oil enters the combustion process it basically reduces octane and promotes detonation. running flat faced valves would give you a slight bump in compression. supertech makes these. as far as the VT goes. if you're using stock cams. more spring rate isn't needed. share your plans for the engine and the springs can be better spoken of. what you do need to have checked is guide to stem clearance with the new valves. just make sure no guides are out of spec. you'll need new seals and a valve job. they are normally $150. make SURE the shop you use knows what they are doing or you could use endyn.

lastly, you might need new piston rings and a hone as well.

 

It's not running that rich, it might dip to 10.5 or so but stays steady around 11.5-12.

I'm going to pop the #4 piston out and take a look.

Thanks for the advice, I'll start calling around the local shops for pricing on valve replacement.

My plans, for now, are to continue to run 10-12psi of boost on a stock compression engine and stock cams. This is my commuter car and it sees alot of miles. I'm just looking forward to getting it back on the road.

 

oh, if you're going to run boost you might not need the extra compression. ferrera has a really nice valve that slightly drops your compression compared to stock. it would help keep you around stockish compression levels when you consider material might need to be shaved from the head or block after you check for warpage. again it depends on your combo and you're more in turn with what you want to run compression wise than we are. often times your bottom end can be done with just rings and a hone....literally. i've seen two engines with great bearings, shot rings and 170k miles. i have no idea what it is with so many gsr's and 170k

if you're keeping stock cams one cheap trick you can use to get more VT stability is moving your blue gsr intake springs to the exhaust valves and buying ITR intake springs for the intake side. you now have dual springs on both sides and could easily rev to 8500 without worry. it's also less than $50 since it all works with your existing locks and retainers.

btw: the ferrera valves are 2-3g lighter than OE

 

And here is #4 piston. The rings look ok to me, what do you guys think.

 

Anyone think the rings are good or bad? They look ok to me.

 

My apologies for bumping an old thread, but since I am going through some valve issues myself I am curious as to what ended up happening with this. The issue must have been resolved by now.