kkim

This happens after the car is fully warmed up... when I turn off the ignition and the engine comes to a stop, there is sort of a "rattling/clatter" noise. Seems like it's internal to the engine and only for a split second after shutoff.

Does anyone else experience this? Normal or not?

chris walrod

Some have reported this to be attributed to a worn DMF. Do you still have the standard DMF in the car?

kkim

Hmmm.. Yes... original DMF.

This has nothing to do with the clutch? The clutch seems fine.

Thanks, Chris... I'll do a search and try to find more info.

mleds

I shut my engine off a few times this week trying to pinpoint the same noise. I definitely have the same noise but had it on my 2 prior 993's too. I too have the DMF original clutch setup. Is the noise that you are referring to sound metal-to-metal?

kkim

Yes. Sort of a "clatter"??? Definitely sounds like it's coming from the lower engine area, so DMF it might well be

Mine only occurs when the car is nice and hot and I turn it off. Restarting and turning it back off while hot will almost always result with the sound.

mleds

Same sound here. I will be playing the stereo until I shut off the car from here on out.

jrgordonsenior

Give it a small rev then turn it off....
JRG

JohnJL

I sense a LWF purchase coming....;-)

kkim

I've read what I could from the archives, but no one has said if they have had an outright failure of the DMF even while having this shutdown noise. Wonder how long before it self destructs???

Anyone know of other signs of a bad/failed DMF or how to check it?

kkim

What does that do?

mborkow

i got my 993 right before the original clutch was about to fall apart and depressing the clutch was a serious workout for my leg. after i had the LWF installed depressing the clutch became much easier. i never drove the car new so i am not sure (and i could be 100% wrong) but maybe the extreme stiffness of the clutch was a symptom of its immanent failure?

kkim

Do you remember if yours made the engine shutdown noise prior to you changing to the LWF?

chris walrod

Last week I helped a good friend install a RS LWF. When we removed the original, ~48K mile DMF, there was a lot of radial freeplay between the two masses of the DMF. Although he never noticed anything abnormal or heard any weird sounds..

jrgordonsenior

Good question and I'll try to make some sense of it.
If you give it a small rev (1500rpm max) and then shut it off as it's coming back down, it seems to "catch" better without the occasional clatter. Whether or not that's the DMF I don't know, but by trapping some compression in the cylinders it appears to stop the engine faster when you eliminate the spark. A manifestation of that procedure is that the "rattle" disappears. Give it a shot...
JRG

Mike J

You can live with a "loose" DMF for a while but eventually it could cause the generation of some CEL code like "random misfire" etc. Essentially the DMFis rattling around causing the sensors to think the engine RPM is inconsitent and thus the engine must be missing.

BTW I think I might have a failing DMF because I get the shutdown rattle, a wierd noise on idle that sounds like a rattling DMF (especially when the car is hot), and the occasional "random misfire" code from the DME. All points to the same thing...

Gotta love over-engineered cars! ;-(

Cheers,

Mike