Flint

Intermittently, definitely not consistently, I will have to rev the engine very high to get any momentum going. Little power off the line and through the gears. It feels almost exactly as if the clutch is slipping (this is a manual car), complete with a burning metal-on-metal smell.

However, I will stop, turn the engine off, and start it again and the car will drive perfectly normally; good power throughout the RPM range, from a stop and through all the gears. I have not spotted a pattern (like, every other time I drive it), if that matters. I did just replace the throttle body boot, which was pretty shot, and it briefly seemed to drive better, but the issues with the TBB may have been masking this for a while.

I haven't found any exactly similar issues searching here, and the most similar ones were from automatic-transmission cars, so it's not quite an equal comparison.

I have a CEL, and I have a generic code reader, but no VAG-Com or whatever it's called now, but I'll see if I can get and/or clear any general codes when I get home from work. Until I do that, anything I should keep a look out the next time it does this? I know without codes it's not too much to go on, but any preliminary guesses would be great as well.

Thanks,

Flint
2001 2.7t 6-speed

Devin

robsa6

You could take the car somewhere you can get to 40 mph or so and put it in 6th. and hold it to the floor while paying attention to the tach to see if the clutch is slipping or not. If it is slipping I cant see it being good one time and slipping the next unless there is something wrong with the pp or something in which case the problem will become apparent quite quickly. As far as the rest goes the generic code reader should pull the codes it probably just wont erase them. post the codes it shows

Flint

I should also say it's had a new clutch within the last 5 years as well. Yesterday, it drove completely normally. And this morning it drove fine on my way out to drop my kids off. But when I went to leave, the car could barely make it up the hill in 1st gear. Luckily, my kids are watched by my parents, so I was able to leave the car there and borrow one of theirs. So it likely won't be till tomorrow that I can get codes off it.

And I have no idea if this is related, but sometimes it is very hard to get the car out of first gear. 2-6 shifting is fine. Reverse is sometimes "sticky" as well.

robsa6

Does the check engine flash when this is happening? engine rev unusually high? Codes?

Flint

The CEL is on constantly.

I actually spoke to a local independent mechanic who's familiar with these and he said the symptoms sound just like the Dual-Mass flywheel is going out. He said that would explain why it's intermittent, and the smoky-burnout/hot-brake smell when it's happening.

SloopJohnB@mac.com

Just do it. Figure out whether the dual flywheel is toast or the pressure plate is defective or the clutch plate is worn or a throwout bearing or clutch fork or slave cylinder is toasted or all of the above, but the longer you wait the more change you have of being stranded and having to flatbed the car to a repair shop.

It's unfortunate the clutch was replaced in the last five years, but 'clutch replacement' covers a lot of territory, sometimes it's only the clutch disc itself that is replaced (a case of too cheap IMHO) while the pressure plate, TO bearing/fork/slave cylinder and/or flywheel/pilot bearing, etc., should have been replaced as well.

What exactly was done five years ago for the 'clutch replaced'?

BTW…there are lots of videos on youtube showing worn/failed dual mass flywheels. Most of them indicate there should be rattling/gnashing noises when the dual-mass flywheel is worn/failing.

Flint

The car was owned by my parents when the clutch was done, I'll see if I can find the receipt. It was done by the former head mechanic of the local Audi/Porsche dealership, so I imagine he'd do it properly.

The only noises I was getting was a whine while it was dong it.

mobsTTa

clutch

Flint

Except the clutch wouldn't be going out one day, then working perfectly for two days, then out again.

Could it?

johnkk

This is a guess, but perhaps your slave cylinder is hanging up and not retracting consistently when you release the pedal. Brake fluid flushes often overlook the clutch and I wonder if the slave has developed some corrosion. When it acts up the next time, try pumping the clutch several times to see if that action temporarily fixes the slipping. While not a snap, at least you can replace the slave without pulling the transmission.

I suppose the clutch master could also cause problems like this, but first guess is the slave. Release bearing could be hanging up, but out comes the tranny to check and then you redo the whole works anyway.