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1999 996 Valve spring /Stem ?

Engine

Vehicle Information: Model: Carrera 996 C2 coupe "Tiptronic S"; Year: 1999; Body Type: Coupe; Total Mileage: 73000;

1999 C2 coupe "Tiptronic S" with 73k miles. Purchased used in May of last year. PPI yields no real problems except MAF sensor and compression test is good. Replaced MAF soon there afterI brought it in 1.5 weeks ago for a CEL on. Was told that a solenoid (helps control cam exhaust) on the back right was leaking oil. We put it up on the hoist, looked and saw the mild leak. Porsche fixed the solenoid & it's seal. A few days later I noticed a low idle one time at a stop light. I thought nothing of it as the computer corrected it within no time. It ran fine for a few days. Then this sunday night about 1 mile from my house the enginge starts sputtering and dies. The CEL is now flashing. I restart it and the CEL is flashing for a few seconds, then steady on. I drive it half a mile towards home and when I come to a stop light it dies. I am scared to death so I go one more stop light and it dies again. Same thing. I call AAA and have it towed (flat bed). Porsche has had it now for 2-3 days. The first day they checked the oil for metal... It looks clean. They hook it up to the computer and describe to me that the catylytic converters are sending the computer errors. They checked the intermediate shaft and it looks good. Perplexed the tech said from the the outside everything looks great. No oil leaks, no broken hoses, belts are fine. So I ask the tech and he said something to the effect that the car is runing "rich" and to let him look at it for a few more days. ____________________________________Ok here is the next update:Cylinder leakage & compression tests were done... & #4 is dead. The tech pulled half of it apart and thinks it is the valve, but waited for my approval before pulling the engine. He is hoping that it is just a simple replacement the spring and praying that there was no damage done to the rest of it... He still says that he has to take the engine out because there is no room to remove the parts necessary due to the fact my car is a tiptronic and takes up more space in the engine compartment. If he pulls the engine out though he will go through all of them (4,5,6 on the right side for me and check them out too)Here is the list of fault codes:75- Misfire damage to cat66- Cylinder 4 misfire with damage to cat68- Cylinder 6 misfire with damage to cat53- Cylinder 4 misfire emmisions relevant115 - Hot films MAF sensorEstiamte for repair: $3800 +/-Estimate for factory refurbished engine $9200 with 2 year waranteeNext I asked around if the removal and replacement of the solenoid & it's seal could have caused a timing problem and bent/broke the valve/spring and he said no way... In my car 99' C2 Tiptronic, it is located onthe same side but controls the upper portion and not the lower where the #4 valve is located.... They (3 techs) said that they has only seen this before 1 or 2 times and it was on a boxster - 6 speed and never a 996 tiptronic._____________________________Update #3I have spoke with a very knowledgable guy (from 6speedonline.com) who used to be a Porsche Dealer mechanic for 3 years and now has his own performance shop...His recomendations were to have them pull it all apart and first see if it is a bent valve and if there are any marks on the pistons. (if it is bent, then there are some big decisions I will have to make... I will then have to weigh the costs vs. a re-furbished motorIf not, then replace all the springs #1-6 and thus paying a little more for preventative measures. He said that parts are only $100-200, and to see if Porsche will work with me on some of the labor to bring down the $3000 estimated price as a good will gesture. Feedback? Thoughts? anyone??? Region: San DiegoCar Use: Street use only

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