echo999

So I've been trying to figure out why at idle, I get intermittent thumps/pops
in my exhaust (AEM EMS, 550ccs). I don't have any problems at higher rpms.
I've concluded it's not in the tuning, but
definitely either engine or ignition problem. I've changed out all of my ignition
components, and unless it's some strange EMF interference causing the misfires,
ignition is not my problem.

I've noticed a louder than normal clicking sound in cylinder 1, and I'm somewhat
certain that my problem may be a broken valve spring or bent/sticking valve.
I plan to do a compression test when I get back this weekend, but:

1) Can I tell if I have a bent/sticking valve without taking the head off?
2) What is the purpose of inner springs vs outer springs for valves?
3) How much work is it to pull off the head?

Also, when my idle studders, I notice a puff of white smoke.. faint. I heard that
engine oil is quite combustive.. I'm hoping all I have is a problem with 1 valve, and that oil is getting combusted because of the not-totally closed valve.

Any opinions?




[Modified by echo999, 3:46 PM 2/5/2003]

MiraiZ

clicking valves suggest valve tap...you should have to pull th head off to inspect it...just removing the valve cover might be enought see whats going on.

Second, I had low RPM popping sounds too. I had a warped head gasket which contributed to the problem..

hope this helps

echo999

Well, is there a way to know that a valve is bent/sticking without pulling the head
off?