Do I need a new DMF?
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From: Bologna, Italy
Do I need a new DMF?
I am worried! When I press the throttle right after changing gear I hear a clunk. Somtimes in 5th gear when lugging the engine I hear some drivetrain noise (not really any vibration though).
I have never had any rattles after starting the car or turning it off either. Just want to confirm my own suspicions. Are there any other "tell tale" clues that would indicate a DMF failure?
Andy
I have never had any rattles after starting the car or turning it off either. Just want to confirm my own suspicions. Are there any other "tell tale" clues that would indicate a DMF failure?
Andy
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From: Parafield Gardens
Dear Andy,
I am sorry to say this but your description could account for a million things. I would certainly not tell you that your DMF is gone. A clunk tends to suggest something is loose or out of alignment but falls into place, hence the clunk. The DMF normally causes a shudder and in 5th gear at low speeds you will certainly feel this shudder. It could be a sign of a very early stage of a failing DMF but I would hate to say this and it is something very simple. I think the clunk needs to be explained in more detail. What happens when you back off the throttle quickly. Because you are worried out this, maybe such amechanical problem needs the attention of a local expert.
Please understand that over cyberspace, noises and their causes are tough to work out. We do try our best but miracles can take a little longer and putting a cause to noise that one cannot hear is not easy,
Ciao,
Adrian
911C4
I am sorry to say this but your description could account for a million things. I would certainly not tell you that your DMF is gone. A clunk tends to suggest something is loose or out of alignment but falls into place, hence the clunk. The DMF normally causes a shudder and in 5th gear at low speeds you will certainly feel this shudder. It could be a sign of a very early stage of a failing DMF but I would hate to say this and it is something very simple. I think the clunk needs to be explained in more detail. What happens when you back off the throttle quickly. Because you are worried out this, maybe such amechanical problem needs the attention of a local expert.
Please understand that over cyberspace, noises and their causes are tough to work out. We do try our best but miracles can take a little longer and putting a cause to noise that one cannot hear is not easy,
Ciao,
Adrian
911C4
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From: Bologna, Italy
Adrian,
Thanks for the quick reply! I am planning on taking my car in to have a few things checked out on July 1st.
Regarding the clunk, I've just been out on a quick test drive, I do not get a clunk when I quickly lift off the throttle. What I have noticed, is that it seems to happen each time I floor the throttle, not just when changing gear. ie. Floor it, Clunk, lift on quiet, floor it, clunk etc.!
Any more ideas?
Andy
Thanks for the quick reply! I am planning on taking my car in to have a few things checked out on July 1st.
Regarding the clunk, I've just been out on a quick test drive, I do not get a clunk when I quickly lift off the throttle. What I have noticed, is that it seems to happen each time I floor the throttle, not just when changing gear. ie. Floor it, Clunk, lift on quiet, floor it, clunk etc.!
Any more ideas?
Andy
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From: Parafield Gardens
Dear Andy,
I will need to think about it and maybe dig back in the data. I cannot remember, do you have a C2 or C4. I am thinking more rear diff, rear axles, rear wheels, brake caliper loose. Throttle on also means acceleration. I know it could also mean something in the engine but I do not want to think about that right now.
Do you have a LSD or standard rear diff (C2 only of course). Mind you I admit I am still guessing because, well it is very tough. I had a funny clicking sound on my C4. I removed the rear spacers (see post earlier this week) and the sound went with the spacers. Gone. I have no idea what it was. I had a failed wheel lock nut as well. Could have been the tumbler I suppose. Anyway back to your problem, I think you at least need a second opinion from somebody on the spot,
Ciao,
Adrian
911C4
PS: Years ago I had really weird nosies coming out of what I thought was the front. Horrible sounds. I could have sworn the noise was a front end problem. I took it to my mechanics and it turned out to be both the bearing in the rear drive axles completely failed. Lubricant was gone.
I will need to think about it and maybe dig back in the data. I cannot remember, do you have a C2 or C4. I am thinking more rear diff, rear axles, rear wheels, brake caliper loose. Throttle on also means acceleration. I know it could also mean something in the engine but I do not want to think about that right now.
Do you have a LSD or standard rear diff (C2 only of course). Mind you I admit I am still guessing because, well it is very tough. I had a funny clicking sound on my C4. I removed the rear spacers (see post earlier this week) and the sound went with the spacers. Gone. I have no idea what it was. I had a failed wheel lock nut as well. Could have been the tumbler I suppose. Anyway back to your problem, I think you at least need a second opinion from somebody on the spot,
Ciao,
Adrian
911C4
PS: Years ago I had really weird nosies coming out of what I thought was the front. Horrible sounds. I could have sworn the noise was a front end problem. I took it to my mechanics and it turned out to be both the bearing in the rear drive axles completely failed. Lubricant was gone.
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From: Bologna, Italy
Adrian,
Thanks for you input. I have a 1990 C4. Any ideas are appreciated but I do plan on a visit to my mechanic on July 1.
Regards,
Andy
PS. The clunk only happens when the engine is under load, ie when in gear. It never happens if I rev the engine when in neutral.
Thanks for you input. I have a 1990 C4. Any ideas are appreciated but I do plan on a visit to my mechanic on July 1.
Regards,
Andy
PS. The clunk only happens when the engine is under load, ie when in gear. It never happens if I rev the engine when in neutral.
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From: Parafield Gardens
Dear Andy,
I am still thinking rear diff, rear axles area. I would get it up on a lifter, get the covers off and have a look or naturally wait until you get to the mechanic. I am not comfortable with clunks and continued driving but that is just me. You know it might be just something external that is loose. I think a pre check by yourself is in order.
Ciao,
Adrian
911C4
I am still thinking rear diff, rear axles area. I would get it up on a lifter, get the covers off and have a look or naturally wait until you get to the mechanic. I am not comfortable with clunks and continued driving but that is just me. You know it might be just something external that is loose. I think a pre check by yourself is in order.
Ciao,
Adrian
911C4
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From: Bologna, Italy
Just to let everyone know what was wrong with the car. My mechanic confirmed that it was the DMF on its way out. He said though that it did not need replacing yet & that I should get some more miles out of it befor ehaving it done!!
He checked the rear diff & drive shafts & everything was OK.
At least I now know to start saving the pennies for the DMF replacement!
Andy
He checked the rear diff & drive shafts & everything was OK.
At least I now know to start saving the pennies for the DMF replacement!
Andy
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From: Butler,N.J., USA
High,
Andy, my DMF went about 5000 miles ago and that was the first thing I started hearing before it went was the clunk, I did get a few thousand miles more after the clunk started, and one morning I let the clutch out and away it went, then the shudder started, I was able to limp to my shop for the repair. Start saving. sorry to say.
Andy, my DMF went about 5000 miles ago and that was the first thing I started hearing before it went was the clunk, I did get a few thousand miles more after the clunk started, and one morning I let the clutch out and away it went, then the shudder started, I was able to limp to my shop for the repair. Start saving. sorry to say.
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