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1996 993 Targa - Rough Idle caused by worn valve guides?


Vehicle Information: Model: 993; Year: 1996; Body Type: Targa; Total Mileage: 75,000 miles;

I have looked over all your responses concerning the all-consuming valve guide issue on the 993's, thanks for taking the time to answer all the questions! My car has all the symptoms ; relatively high oil consumption (I don't have the exact usage numbers tracking it now), CEL lights indicating emissions problems, high hydrocarbons in the exhaust, especially pistons 4-6. I am a consumate DYI kindof guy and will likely do a top end job myself (after taking Bruce's course and a lot of study of course). Already did all the suspension, clutch, etc. and am not afraid to try this. The heads will be sent out to be reconditioned and new guides put in. However I have one symptom that has not been mentioned...I have a rough idle. The car idles rough enough to cause a random misfire ODBII code. The exhaust has a ""phut**phut** sound on warm idle. It is random but you can feel the misfire with your fingers in the exhaust stream. I had a local mechanic do a diagnosis on the engine and he concluded that the valves were not seating well due to the guide wear, and that caused the rough idle.Have you seen any occurances where worn valve guides cause a rough idle? I want to make sure I am chasing (and fixing) the right problem. I know the guides are likely toast but is there another problem as well?If I am going to replace the guides I would like to get the best ones ; have you encountered any third party ones that are better than others? I will likely go with your recomendation to remove the springs off the seals to they get more oil...I am sure it will be a topic when I take Bruce's rebuilding course.I am peeved at Porsche for putting crappy guides in a very expensive figure the problem is prevalent enough to get something done about it (likely not!).Thanks in advance!Region: Canada WestTotal Mileage: 75,000 milesCar Use: Combination Street and Track

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