CLunking noise

[mr5296]

hello all, new Porsche owner new to the forums if you haven't guessed already, so i have a 86 944 Na auto transmission, about 150K miles timing belts recently adjusted.

just today as i was getting it smogged i put it into drive and i heard this loud clunking noise kind of what a diesel motor makes, well when i accelerate the noise goes away it only makes this clunking when i put it into drive and reverse at idle, no noise when its in neutral or park or when accelerating.

any thoughts would help

thanks

[John_AZ]

MR5296 hello and welcome,

I may be the bearer of bad news and I hope I am wrong.

It may be your automatic "flex plate" that needs replacing. The part alone is about $1150-$1200. It sounds as if your "make it home tabs" on the plate are clicking.

Here is a recent link member tidybuoy just put up and finished his replacement. He would be the current expert on your car and noise.

Holy Crap Batman! Shredded Flex Damper Photos


GL & welcome
John

[Tidybuoy]

Originally Posted by mr5296

just today as i was getting it smogged i put it into drive and i heard this loud clunking noise kind of what a diesel motor makes, well when i accelerate the noise goes away it only makes this clunking when i put it into drive and reverse at idle, no noise when its in neutral or park or when accelerating.

I haven't finished my project yet but I'll be done within a week.

On my car, an '88 Automatic, everything was fine and then suddenly a loud clanking sound started coming from the engine. It was a horrible noise and sounded like a bolt had come lose inside the engine.

The noise was only present at idle and went away as soon as I started driving. I was able to drive slowly and get home. I started the engine a couple of times and the noise was back - loud clanking and very disturbing.

I had read about the "Flex Damper" but I did not think this was the problem in my car because this noise sounded like it was from inside the engine & I only have 49k miles on the car - it's still 22 years old though.

To confirm the flex damper: jack up the front of the car (put on stands) and get under the bell housing where a clutch would be on a manual. Ther are inspection holes that are covered with a rubber plug. It's almost impossible to see the flex damper thru the holes but rubber crumbs should fall out when you remove the plug. Also, with the plug removed, if you start the engine, small chunks of rubber will fall out of the hole.

Unfortunately, it's an expensive repair and I was quoted by my local shops to be around $2500 to fix. I chose to do this myself and the new damper was $1200. This is, unfortunately, a part that needs to be purchased new as an old used part could go bad and the labor to install is about 20 - 30 hours.

There are virtually no directions on the net to replace this part as everything I could find related to manual cars. But, the procedure is similar to doing a clutch. I was very worried about doing this job but now that I have done it, it was not nearly as bad as I was expecting - go to Search Results for "clarksgarage.com" and find the procedures for doing a clutch. I used the directions like a checklist and just went thru each step. I also referred to the 944 shop manual. You really have to use multiple sources to get a full understanding - the shop manual is great but assumes you are working out of a certified Porsche garage and refers to many tools, jacks, lifts, etc.. that most home mechanics don't have.

I found that removing the transmission completely was the way to go and gave me plenty of working room to move the torque tube out of the way, enough to get the damper replaced. Just realize that this job will take time. I spent about 3-4 hours a day and had everything disasembled in a couple of days. Putting everything back is taking a little longer but only because I'm doing some additional repairs while I'm at it (i.e., new exhaust gaskets, new power steering reservoir, replacing some hoses & bushings).

Good Luck.....Vern

[mr5296]

yeah i looked under theree today and saw little cracks in the flex damper, no rubber was falling out or when it was started but i stuck my finger in there and noticed a chunk missing about a quarter size, so yeah i am going to have fun with this. So how long do you thing it could go before totally blowing out? So i was looking up some stuff and i read that you can use a manual flywheel and clutch plate to replace the rubber flex damper. anyone care to elaborate? is there any special modifications that need to be done for this to work?

[mr5296]

so after a long and arduous journey replacing my shredded flex plate i finally got everything back together and it all works..thank god., but just one problem, the clunking noise is still there, i am going to jack up the front of the car and try to find out where its actually coming from, but f*ck this is awesome....lol any suggestions to what else it could be?

[83supercarrera]

If it's coming from the engine a clunking or pots and pans type of sound may very well be a spun bearing, which should be fixed asap

[mr5296]

well it sounds like maybe its coming from the front bell housing area, but i will check sometime to night just to make sure.

[mr5296]

well i changed out the transmission fluid and let the car run and found out the noise is actually coming from the read where the torque tube connects to the transmission,
any ideas, it sound like a clanking noise

[John_AZ]

GL
John

[mr5296]

so is there anything else it may be, it sound like it is coming from the front bellhosing and the rear?

[arttrout]

I have been told that the clunking sound could be the torque converter, aobut $800 new for the parts.

[mr5296]

but what ppart of the torque converter could be causing it, since its just a casing filled with fluid. like i said it sounds like it coming from bothe the front and the rear but i cant tell since sound travels easy through metal. the sound does go away when you drive its just at idle that the sound starts, it sounds like my car is a POS...lol

[arttrout]

Not sure but had heard from other boards and also cause the local Porsche dealer charged me 800 to replace the motor mounts to cure a similar sound, and then told me it was probably the converter. Never going back to him again!

[KEV951]

check motor mounts, put in drive, hold breaks , revv up and check each mount, then do the same in reverse, otherwise , it totally sounds like your torque converter is acting up

[mr5296]

so does anyone know exactly what part of the torque converter could be causing this, if it is it. I mean there aren't that many parts on it, i did replace the torque converter seal before i put it back on. but i will check the mounts today.

[KEV951]

the converter itself can go bad and probably did, there is no repair kit for a torque converter

[mr5296]

So i took the advice of all and put the car on ramps and listened and noticed it was predominatly coming from the front bellhousing, i i took off the inspection cover by the starter and looked in and to my amazment the was about 1.5 inches of clamping screw sticking out and spinning with the drive shaft, ha nice. So i'm thinking that its come loose this whole time right? Wrong, my dumba$$ put it in the wrong way...hahaha i know, so it wasn't counter sunk like its supposed to be,
well atleast i didn;t drop the 500 on a torque converter huh, or on engine mounts..nice...heres a pic of the bolt just incase someone else replaces their flex damper and wants to double check....

[mr5296]

[89s2]

having my flex plate replaced. dealer will do it 4 $700 for labour 51/2 hours labour wounder why tidyboy took 20-30 hrs

[mr5296]

when i called the dealer they said its anywhere from 13-16 hours of work and thats with the people that have done it before, lifts and the right tools.
it took me about 25 days working on and off of it, a couple of hours here and there. Whatever dealer you are going to hook it up i want that guy cause i called around and a lot of places it was 2-5k for labor and parts...