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Old 60's Porsche Tech
Join Date: Jan 2009
Posts: 369
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Exhaust valve guide causing oil consumption
I am using a quart of oil every 470 miles. I have good compression, car runs strong. Leak down result of 35% to number three into exhaust. 5 and 6 20% into exhaust. Other cylinders are around 5%. Compression 160 all but # 3 145. I have been told by s couple forum members that I risk dropping the valve on # 3 if I keep driving the car. Plugs read nice tan ash all cylinders. I have decided to do a top end job as soon as I have the money 3.2 95k miles. What is the downside, other than some smoke and having to add oil. Am I causing any damage except potentially plugging the converter. some engine gurus please chime in, thank you
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1987 911 Cab TRE engine  1952 356A sold  ,1960 356B totaled hit by drunk totaled  1979 911 sc Targa sold,1984 911 3.2 Targa sold,1985 911 3.2 Coupe sold 1987 3.2 coupe sold to my son PARTS ENDLESS WORK $$$$$ PREPARING and driving your PORSCHE anywhere with confidence PRICELESS!!
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05-20-2016, 08:06 PM
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Registered
Join Date: May 2003
Posts: 3,346
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Unfortunately you are risking a broken valve. The loose guides don't allow the heat to escape from the valve and the head breaks off.
-Andy
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72 Carrera RS replica, Spec 911 racer |
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05-20-2016, 08:48 PM
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Registered
Join Date: Feb 2007
Location: Northeast
Posts: 463
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Eagle is spot on. And you risk burning a valve and or seat=which I'll be happy to repair for you of
course-but cheaper to do the top end before that-like you didn't already know that.
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Mark www.exotechpower.com 1981 Targa-messed with. 91 C2 supercharged track rat Radical Prosport-irritates the GT3 guys 40 years of rebuilding services |
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05-21-2016, 04:21 AM
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Registered
Join Date: Mar 2004
Location: Windsor, CT
Posts: 2,119
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Yes, the #3 exhaust valve is no longer sealing properly. The guide is worn. Both will contribute to overheating the valve and stem. At some point in time, that valve will break off and destroy at least that cylinder and head. And at worst put a big hole in the piston and spray debris throughout the engine and oil system. And will happen at anytime, but likely as you are hauling a** and can't quickly shut it down.
So you have a very tough decision. How long do you want to push it. Fixing it now, by yourself will run a few thousand dollars. All the heads need to be rebuilt with new valves. About $1300-1500. Gaskets and seals another 200-300. If you don't touch anything else (which is IMPOSSIBLE) maybe you are done. Letting it go to failure. Well now you are getting on a 10-20x factor. Like $15000-$20000 easy. Everything will be replaced or repaired. And that is without labor. Not trying to scare you. But you should be.
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Mike '82 911SC, SSI, 22/29 tbars, 22F/22R Adj swaybars, Bilstein Sport, Elephant polybronze & monoballs, Cambermeister bar, turbo tierods, Carrera oil cooler, front brake cooling ducts, Sparco Sprint 5 & Recaro SRD PAX seat, Teamtech harness, DAS Sport rollbar. |
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05-21-2016, 04:23 AM
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Old 60's Porsche Tech
Join Date: Jan 2009
Posts: 369
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Thanks guys, I will leave it parked until I can come up with the money.
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1987 911 Cab TRE engine 1952 356A sold ,1960 356B totaled hit by drunk totaled 1979 911 sc Targa sold,1984 911 3.2 Targa sold,1985 911 3.2 Coupe sold 1987 3.2 coupe sold to my son PARTS ENDLESS WORK $$$$$ PREPARING and driving your PORSCHE anywhere with confidence PRICELESS!!
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05-21-2016, 06:06 AM
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Old 60's Porsche Tech
Join Date: Jan 2009
Posts: 369
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In Los Angeles area best recommendation for 911 engine work, I am looking at TLG in north Hollywood and TRE in Van Nuys any comment or other recommendations?
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1987 911 Cab TRE engine 1952 356A sold ,1960 356B totaled hit by drunk totaled 1979 911 sc Targa sold,1984 911 3.2 Targa sold,1985 911 3.2 Coupe sold 1987 3.2 coupe sold to my son PARTS ENDLESS WORK $$$$$ PREPARING and driving your PORSCHE anywhere with confidence PRICELESS!!
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05-21-2016, 06:44 AM
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Old 60's Porsche Tech
Join Date: Jan 2009
Posts: 369
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Bump
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1987 911 Cab TRE engine 1952 356A sold ,1960 356B totaled hit by drunk totaled 1979 911 sc Targa sold,1984 911 3.2 Targa sold,1985 911 3.2 Coupe sold 1987 3.2 coupe sold to my son PARTS ENDLESS WORK $$$$$ PREPARING and driving your PORSCHE anywhere with confidence PRICELESS!!
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05-22-2016, 09:28 AM
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