Stock WG valve guide failure
09-24-2009, 10:36 AM
#1
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Stock WG valve guide failure
Had mine chunk apart and a piece stuck the valve open. Somewhat typical failure for factory waste gates or is this a possible symptom of excess EGTs?
Since the guide is ceramic, I am assuming no way to replace it (so valve body is junk).
Since the guide is ceramic, I am assuming no way to replace it (so valve body is junk).
Last edited by Oddjob; 09-24-2009 at 10:53 AM.
09-25-2009, 11:22 AM
#2
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John
09-25-2009, 04:10 PM
#3
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Thread Starter
This same failure happened to a friend of mine at the track driving my old '89 Turbo S. It is stock with the exception of weltmeister chips and minor headwork. Car has 220K miles! As only the ceramic part that protruded below the cast metal of the wastegate housing chunked off, it was reassembled and it works fine.
John
John
This was on a Lindsey Clubgate, so who knows where the core came from or the mileage. I had a spare stock WG along, so installed that at the track. Have not torn down the "busted" one, so dont know the extent of the guide cracking.
Symptom was that at 4k rpm, zero boost, but would actually start building boost over 5k rpm and was at full boost at approx 6.5k. That gives a good indication of the WG valve actuation - should be fully closed at 3-4k rpm, and will be approx 1/4" open at redline (depending on boost level).
