Stranger than strange noise!!
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Joined: Feb 2003
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From: Chicago
Stranger than strange noise!!
1998 C2S 15,000 miles...we had found 2 totally collapsed lifters and 3 that were "squeezable". We had excessive buid-up on driver's side exhaust valves. We replaced the lifters and removed the build-up and checked the valves and valve travel....BUT after putting car together we still have valve "slapping" and what sounds like the valve hitting the rocker and the rocker "slapping" the cam. Has anybody run into sticky valves (intake valves) and exhaust valves on a car with 15,000 miles. What recommendations other than a complete tear down????
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Joined: May 1998
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From: Somewhere....
Hmmm........ Couple of things....
The rocker shafts - you torqued them to spec, so none have pulled away from the CAM..???
When you cleaned the "crud" off the valves - none fell into the seat - so that the valve won't fully close? A compression test would point that out pretty quickly....
When you replaced the lifters - did you prime them with oil???
Hmmmm - still thinking, but those are off the top of my head....
The rocker shafts - you torqued them to spec, so none have pulled away from the CAM..???
When you cleaned the "crud" off the valves - none fell into the seat - so that the valve won't fully close? A compression test would point that out pretty quickly....
When you replaced the lifters - did you prime them with oil???
Hmmmm - still thinking, but those are off the top of my head....
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Joined: Feb 2003
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From: Chicago
The noise now is a valve slap....the noise comes and goes...could we sticky valves from sludge from the intake runners on a car with 15,000 miles? (primed the lifters for 3 days with oil, torqued to spec..etc.)
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Joined: May 1998
Posts: 10,005
Likes: 60
From: Somewhere....
Honestly - if it were me - at IDLE ONLY - I'd take a mechanics stethascope (sp??) and try to pinpoint exactly which bank and which valve.. Once you have that, remove the cover and take a close look at the clearance and remove that rocker/shaft to check that the shaft oiling hole is correctly aligned to the rocker. If that looks good, then I'd suspect a lifter issue (Steve W. - have you seen a new one fail)> Also - I'd pull the lifter and be CERTAIN that none of the old sealing ring in lodged into the rocker arm...
Any one else on-line have other suggestions that I've probably missed???
Any one else on-line have other suggestions that I've probably missed???
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Pro
Joined: Jan 2004
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From: NYC
Originally Posted by Pablo
Has anyone come across a car with sticky valves at 15,000 miles?
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Burning Brakes
Joined: Oct 2003
Posts: 921
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From: Wilton, CT
From what I understand, excessive heat can cause the lifter seals to give out regardless of mileage. Also, the tiniest little fleck of debris in the oil can jam up a lifter, which also would have nothing to do with the mileage. I assume that, because our engines are high performance, air-cooled, and are therefore prone to higher operating temperatures, there is a high incidence of lifter failure.
(Based on what I've seen, it definitely seems common on this board.)
I can't imagine, however, actual valve/valve guide wear at 15,000 miles.
(Of course, it's possible the car has never had an oil change...
)
(Based on what I've seen, it definitely seems common on this board.)
I can't imagine, however, actual valve/valve guide wear at 15,000 miles.
(Of course, it's possible the car has never had an oil change...
)
