Lil bastard

TRANSLATION: Pooping in my pants... Help!!

Background:

1990 Carrera 4 Cab. Bought it two months ago at 20k mi. from orig. owner after thorough PPI from Champion Porsche who gave the car an A+, and subsequent inspection by Randy Edersole along with an oil change at Autoworks, Inc. in Macon, GA on my way home from picking up the car in West Palm Beach to MSP. Randy couldn't believe the car's excellent condition. In addition to the oil change, Randy (a friend of a friend), also removed all the underpanels and inspected the drivetrain which was all sealed and dry, incl. front diff.

The trip home went flawlessly, the car tight and everything working properly (except the Cruise Control, which worked once you jiggled the clutch pedal with your foot).

Have put nearly 4k flawless miles on it since ranging from City driving to Interstate and highway driving, touring around the state. I do not drive the car hard, don't beat it, but have driven it at 7/10ths a couple times, not recently. Never any 'launches'. Only replacements I made were a new battery (it still had the orig. 20 y.o. battery) and a new set of tires (still had the originals), and topped up the oil.

BTW, I just came from 6 yrs. in a Boxster and have a 911T and an SC in my past so I am familiar with the breed, just not the 964 or AWD.

Today:

Actually checked oil today prior to driving the car in town about 7 mi. to meet a friend for lunch - car ran perfectly, weather sunny, mid-70's. Finished and detoured on my way home to another friends taking a scenic drive, steady 30 mph, 3rd gear. Ahead is a very Senior Citizen (not that there's anything wrong with that) running between 15-20 mph. On a long straight, with no oncoming traffic, I shifted from 3rd to 2nd and passed the older guy, hitting maybe 55 before pulling back into my own lane. Seemed like a smooth maneuver, no hanging clutch or over-revving whatever.

Since that pass, whenever I shift, the clutch goes in smoothly, shift is smooth, but when I let the clutch out, after it engages, there is an audible 'click' from what seems the tranny and I can feel the 'click' in the clutch pedal. Also, when I unload the engine, as in decelerating, I again hear the 'click' even though I'm still in gear. If I baby the shifts with no load, the click is gone. No warning lights, car runs smoothly, starts right away. I did notice that when taking a curve, if I accelerate slightly, I get what's best described as a slight 'whirring' sound from the outside rear. Oil level is good, and there are no leaks from the car. Clutch pressure is same as before and shifting is the same.

Ideas?

Major? Minor? I have my own idea what it may be, but don't want to prejudice any responses. I'm not over the sticker shock from the purchase yet and hope I don't have a major repair in my near future - wife won't be happy as we altered our vaca plans to purchase the car and bring it home.

I have a friend who's a major wrench in town, not Porsche specific, but all high-end stuff - Ferraris, Lambos, did a 3.8 rebuild last week on an '86 SC when I was there. I'll have him check it out, but would like some ideas before I do.

TIA!

Cheers!

Indycam

Your low mileage 1990 clutch has started to come apart because its 20ish years old ?
That's my guess .

Lil bastard

That's a good thought Thanks!

But, I don't think so because it grabs well, has no slippage and all is fine if I don't have the motor revving high enough to load things up during the shift.

Still, I'll have my friend (wrench) consider that possiblity.

Btw, I'm not trying to 'stump the band', it's just that people here are waay more smart when it comes to the 964 than I am, the learning curve looks fairly steep from where I'm sitting right now.

Cheers!

IanR

Might be the flywheel. The dual mass flywheel uses rubber dampers between the 2 parts - after 20years that rubber can't be in very good shape.

springer3

+1. Almost every 964 experienced early DMF failure. That and the leaking cylinder head seals gave the model a bad reputation. Ironically, 964s are now getting a reputation for being nearly bullet-proof, because there are few problems after those got fixed.

PO's records show my DMF was replaced under warranty in January 1997 at 23,958 miles. If the DMF has not been replaced, that if very likely the problem. I do not know if Porsche will honor the warranty based on the low miles.

Nader Fotouhi

I do not have experience with the DMF, but clanking after letting the clutch out is a classic sign of bad rubber centered clutch. For what its worth, I drove the car (a 944 S2) home from track and to the shop (>250 miles). As long as the pieces of rubber does not come off and get jammed between things, the car shifts fine.

Jim Richards

Dual Mass Flywheel. This is exactly what I experienced in my old '95 993. A new flywheel (and clutch kit while I was in there) solved the problem. The old (bad) DMF rubber between the two steel "masses" Was allowing too much movement, hence the click (or clunk, if you will).

Jon Hansen

Your symptoms mirror my experience before DMF failure. You should plan on a clutch job in the near future.

Indycam

5 votes for a clutch .
A very rare agreement on rennlist .

Indycam

The clutch is not a old style normal clutch .
The 1989 had a normal clutch , from 1990 on they used a clutch that has a failure that is unusual , the clutch does its job fine while coming from togetherness and making funny noises .

Lil bastard

OK - Thanks for the replies.

Well, here was my thought, Motor Mounts. Even though it hasn't affected the smothness or alignment of the shifter, the fact that the symptoms occur when the engine/drivetrain is loaded and not when unloaded says to me the engine torque moves the whole assembly.

But, I see where the DMF would pretty much do the same thing. Interesting that the group hates the DMF and that the DMF is such a problem.

The Boxster uses a DMF and while it frustrates many because they cannot reface it when swapping the clutch, it has few reported failures, in the Boxster, it is not cited as one of the model's weak points. Is there that much difference in the engineering of the two? The Boxster has about the same HP as the stock early 964, but I admit that due to displacement (or lack thereof), it has a much lower torque rating.

OK - assuming you are all correct, that indeed it is the DMF. Do I replace it with another DMF or do I go to a single mass unit, even though these have experienced issues such as engine idle and deceleration problems? My inclination, given that this is a non-track Sunday car is to go with the DMF. But, I'm interested in what you all have to say.

In the meantime, the car drives great after the shift, and evcen that isn't an issue if I don't load it up while shifting. I guess I'm asking can this be driven as is for a while, if not, even to the mechanic? What will a total failure be like, or will it fail totally? Will it just get noisier and more obnoxious? I want to address it, but it sounds like a $2500-$3k proposition, and that's not going to be pleasant right now.

TIA!

Cheers!

Jim Richards

I went through this stage, too, where I kept looking for alternative possibilities for why my car was making this clunk. I must have spent a year or more going through "denial." In the end, I decided I should do something about it. When I replaced my DMF, I used that opportunity to replace the clutch kit, and also perform the 60K service on the engine. It was so much easier with the engine on the stand...getting to what would've been nearly impossible to reach places if I had tried doing the service in car. I ended up putting in a new DMF. I think that engine drops aren't all that hard (BTW, it's worse on a 993 than 964), so I would've been fine replacing it again sometime down the road had I had kept the car.

Indycam

I don't hate the DMF , I have an 89 .

No problem , imho , the two parts that are smacking into each other will not care .
My guess , and it is only a guess is that you could drive it for thousands and thousands of miles with no real problem .

Have you seen that you can put a single mass into your car ?

Jim Richards

Yes, you can go for quite some time.

Lil bastard

Guys,

You've dropped my blood pressure a bit with your replies.

It's terrible to me not having a car that's perfect, and I will tend to this asap. But, as things usually have it, issues crop up at the worst possible times.

A BMW 2002 restoration right now has been feeding on my wallet pretty well, and almost complete, but now the Porsche seems to be competing for resources.

I'm in the midwest, meaning the car will go into storage within 60-70 days. My wife travels 50% of the time, incl. weekends, and given the possibility of some inclement weekends, that probably leaves us with maybe 3 or 4 where we can go out and enjoy the car, see the leaves, etc. Knowing it's current condition, I'll baby it until I can get it repaired next early spring.

I am a fairly accomplished wrench having done engine/tranny rebuilds, brakes, bearings, suspensions, etc. on past cars - 240Zs, Lotus Turbo Esprit, 911T, as well as my '02, not to mention my motorcycles and numerous friend's cars of every make/model. Maybve by spring, I'll have researched the issue enough to gain the confidence to tackle the job myself, but right now it's all scary and new.

Thanks again!

Cheers!