Valve job Question
05-04-2003, 06:03 PM
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Valve job Question
Still fighting the check engine light -- still getting misfires at 3 of 4 cyl. What's the best way to determine if you need a valve job? Leak down test?
How much should a valve job cost? labor and materials -- worst case
Thanks
How much should a valve job cost? labor and materials -- worst case
Thanks
05-04-2003, 06:42 PM
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Jeff,
Sorry, I can't address the cost of a valve job on our cars...and I want to keep it that way for a long while. But a Leakdown Test will help determine whether your valves are seated/sealing properly.
...OTOH, I'm not convinced that this is necessarily the source of your problem. Forgive me if this has been an on-going problem and I missed the discussion threads, but if your cylinders 3 (and?) 4 are "missing," have you addressed all ignition-related components such as plugs, wires, cap, rotor, and perhaps anything else I failed to mention?
Moreover, is your check-engine light reporting ONLY the missing cylinders? Seems to me a number of threads have mentioned the CE light in context to clogged passages in the head fed from the air pump. Therefore, this really is only a concern at registration time, though it's a nuissance.
But I also recall someone here designing a simple circuit to fool the DME (not the DMV...they're already fools) into "no fault" even if those nasty little passages are stuffed closed.
Still again, I remember someone swapping the O2 sensor (plural for you) and that cured it.
Disregard my ramblings if you've done all the above. It's just that I'd hate to see someone go in and do an labor-intensive (read: expensive)valve job when the source of the malady is elsewhere. Good luck.
Edward
Sorry, I can't address the cost of a valve job on our cars...and I want to keep it that way for a long while. But a Leakdown Test will help determine whether your valves are seated/sealing properly.
...OTOH, I'm not convinced that this is necessarily the source of your problem. Forgive me if this has been an on-going problem and I missed the discussion threads, but if your cylinders 3 (and?) 4 are "missing," have you addressed all ignition-related components such as plugs, wires, cap, rotor, and perhaps anything else I failed to mention?
Moreover, is your check-engine light reporting ONLY the missing cylinders? Seems to me a number of threads have mentioned the CE light in context to clogged passages in the head fed from the air pump. Therefore, this really is only a concern at registration time, though it's a nuissance.
But I also recall someone here designing a simple circuit to fool the DME (not the DMV...they're already fools) into "no fault" even if those nasty little passages are stuffed closed.
Still again, I remember someone swapping the O2 sensor (plural for you) and that cured it.
Disregard my ramblings if you've done all the above. It's just that I'd hate to see someone go in and do an labor-intensive (read: expensive)valve job when the source of the malady is elsewhere. Good luck.
Edward
05-04-2003, 06:44 PM
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Jeff,
I don't know what is up with your car but I would get it to a different shop for a second opinion. Call John at Wright Tuning (if you need the # send me an email) . My guess is it is not a "valve" issue but something electrical. You said you replaced the plug wires, did you also replace the distributor? Was your car one of the 993s that needed a wiring harness replacement? I now this wasn't just limited to the '95 models.
I don't know what is up with your car but I would get it to a different shop for a second opinion. Call John at Wright Tuning (if you need the # send me an email) . My guess is it is not a "valve" issue but something electrical. You said you replaced the plug wires, did you also replace the distributor? Was your car one of the 993s that needed a wiring harness replacement? I now this wasn't just limited to the '95 models.
05-04-2003, 06:54 PM
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Ed and Greg -- thanks for the response and thoughts.
I replaced all the electrical my mechanic could get his hands on -- plugs, wires, caps, rotors -- cost me a ton. The failure continues to be in cyls, 1, 2, and 3. I think I have to look at the DME and a valve job. The car only has 35K on it but the guy I bought it from never removed the engine pan -- I did. This may have caused a lot of heat leading to the valve job. I think the leak down test is the next locigal step.
I replaced all the electrical my mechanic could get his hands on -- plugs, wires, caps, rotors -- cost me a ton. The failure continues to be in cyls, 1, 2, and 3. I think I have to look at the DME and a valve job. The car only has 35K on it but the guy I bought it from never removed the engine pan -- I did. This may have caused a lot of heat leading to the valve job. I think the leak down test is the next locigal step.
05-04-2003, 07:21 PM
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Jeff,
Leak down test is obviously very sensible. However I tend to agree with Edward and Greg this has the ring of an electrical fault. I would if it were my car I would be getting it double checked by a seriously competent auto electrician. All the best with finding the cause, keep us posted.
Leak down test is obviously very sensible. However I tend to agree with Edward and Greg this has the ring of an electrical fault. I would if it were my car I would be getting it double checked by a seriously competent auto electrician. All the best with finding the cause, keep us posted.
05-04-2003, 08:27 PM
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I had a CEL (Cash Evaporation Light) problem at 47K miles with my 96 993TT. Repeated CELs and misfire codes ultimately led to $9000 valve job at dealer (undoubtedly less costly at independent shop). In cylinder leak down test, car tested out of spec in 3 cylinders. But runs great now. Labor would be less for NA 993 as don't have to deal with all the turbo stuff.
PS: I just got my Boxster back from the same dealer getting replacement engine on warranty, due to oil leaks they couldn't fix after repeated tries. Car had 9 months left on warranty. New engine comes with 2 year factory warranty.
30 years ago had engine failure on my '68 912. Wonder if I'm P car engine cursed?
--------------------
LeeR
1996 993TT
2000 Boxster
PS: I just got my Boxster back from the same dealer getting replacement engine on warranty, due to oil leaks they couldn't fix after repeated tries. Car had 9 months left on warranty. New engine comes with 2 year factory warranty.
30 years ago had engine failure on my '68 912. Wonder if I'm P car engine cursed?
--------------------
LeeR
1996 993TT
2000 Boxster
