Trevace
New member
Hi,
1st Thread, and sorry, its another tapping question.
I know there are 1 million threads on this topic (because I've read them all, some more than twice!). I just can't find one which describes the exactly the tap I have! And i know ultimately, I'm probably not going to get a definitive answer here, its going to need a professional and probably a boroscope to diagnose.
The car is a 1998/99 996 3.4 C4. Just over 100K miles. All standard except exhaust. I did find in the service history that its running an aftermarket ECU map. 75K of main dealer service history with the remaining in the main at specialists. Runs great, no drop in performance I can feel. I bought it last summer and have never topped up the oil which shows full on the in car electronic gauge and mid way between upper and lower limit on the dipstick. Oil pressure looks all good and does what you'd expect with engine temp/ revs. But its tapping!
I don't drive it often at all, its garaged and I take it out for a (usually spirited) drive when I can. I didn't notice the noise when I bought the car, or for many drives. But then I noticed it and had the usual new 996 owner panic. There is a reason i hadn't heard the noise and that is that it only does it under specific circumstances.
Before I bought the car, my research made me think that the 3.4 versions were less prone to bore scoring? But I'm keen to hear from anyone who has had similar (particularly if its a good news story).
Many thanks for taking the time to read this. Hopefully you can put my mind at ease until the car gets serviced and an expert opinion in spring.
Trev
1st Thread, and sorry, its another tapping question.
I know there are 1 million threads on this topic (because I've read them all, some more than twice!). I just can't find one which describes the exactly the tap I have! And i know ultimately, I'm probably not going to get a definitive answer here, its going to need a professional and probably a boroscope to diagnose.
The car is a 1998/99 996 3.4 C4. Just over 100K miles. All standard except exhaust. I did find in the service history that its running an aftermarket ECU map. 75K of main dealer service history with the remaining in the main at specialists. Runs great, no drop in performance I can feel. I bought it last summer and have never topped up the oil which shows full on the in car electronic gauge and mid way between upper and lower limit on the dipstick. Oil pressure looks all good and does what you'd expect with engine temp/ revs. But its tapping!
I don't drive it often at all, its garaged and I take it out for a (usually spirited) drive when I can. I didn't notice the noise when I bought the car, or for many drives. But then I noticed it and had the usual new 996 owner panic. There is a reason i hadn't heard the noise and that is that it only does it under specific circumstances.
- Only when the engine is hot is the noise constant. Although, sometimes sounds like a standard sticky tappet on start up which fades/ stops in seconds.
- Only at idle with AC off
- Disappears if the AC is on (which might be why I didn't hear it to start with, or it wasn't there). Turning the AC on increases the revs slightly, enough that one you've pressed the throttle once the sound goes.
Before I bought the car, my research made me think that the 3.4 versions were less prone to bore scoring? But I'm keen to hear from anyone who has had similar (particularly if its a good news story).
Many thanks for taking the time to read this. Hopefully you can put my mind at ease until the car gets serviced and an expert opinion in spring.
Trev