engine vibration

[RICHBLUEBOX]

hello all, i have a strange vibration at around 3200 rpm when slowing down. the car is a 1999 2.5 manual uk car. i hope this is not a possible engine prob. the car car has done 90k. give me some good news please.

[geza]

Check the CV joints and the suspension bushings - vibrations can be difficult to pinpoint - but a process of elimination of suspension bushings & wheel alignment/drive shafts/and other non engine items will help a lot.

[Chris_in_NH]

do you feel the vibration through the steering wheel, from your seat, through the brake pedal?

does it happen in all gears at 3200 RPM?

are you stepping on the brakes when it happens, or does it happen if you just let the car decelerate on its own?

is it a very fast vibration that changes with speed?

does the vibration also make a noise or is it just vibration?

if you had to guess, would you say the vibration is coming from the front or rear of the car?

it could be a number of things. warped flywheel, exhaust mounts, motor mount, unbalanced wheel(s), etc.

here's a pic of the exhaust system and part #6 is an additional support bracket that has lessened a similar decelerating 3K RPM vibration for some Boxster owners. it's ~$40 USD.

and here's a really good thread on DIY motor mount replacement.

http://www.ppbb.com/boards/ppbbphp/showfla...true#Post116527

[rushrevisited]

Rich,

What was the diagnosis on your vibration at 3200 RPMs?

I have the same issue going on and the dealer tells me it is the DMF and want about $1000 to replace it. I am very leary of this and would like other's input on it...

[lightrail]

Rich,

What was the diagnosis on your vibration at 3200 RPMs?

I have the same issue going on and the dealer tells me it is the DMF and want about $1000 to replace it. I am very leary of this and would like other's input on it...

I have a 2002 Boxster 2.7 with 30k miles. I had noticed a little vibration in the drivetrain when de-accelerating from around 4000 rpm. I mentioned this to the dealer during a 30k maintenance. A tech drove it and diagnosed a bad DMF. I had them change it. I got the car back and found a new and annoying vibration around 3000 rpm. This vibration occurred each time the tach hit 3000, even when there was no load. I took it back to the dealer, the service manager revved the engine to 3000, and noted the vibration. The next day, the dealer called and advised I needed a front motor mount. I had them do it. I got the car back, and it still had the 3000-rpm vibration. I returned the car to the dealer, they re-replaced the DMF, and installed a clutch kit. Still, there was noticable vibration at 3000 rpm. The dealer has requested advice from their support, I've been without the car for 5 weeks, and I'm a little worried.

[spongebob]

Rich,

What was the diagnosis on your vibration at 3200 RPMs?

I have the same issue going on and the dealer tells me it is the DMF and want about $1000 to replace it. I am very leary of this and would like other's input on it...

I have a 2002 Boxster 2.7 with 30k miles. I had noticed a little vibration in the drivetrain when de-accelerating from around 4000 rpm. I mentioned this to the dealer during a 30k maintenance. A tech drove it and diagnosed a bad DMF. I had them change it. I got the car back and found a new and annoying vibration around 3000 rpm. This vibration occurred each time the tach hit 3000, even when there was no load. I took it back to the dealer, the service manager revved the engine to 3000, and noted the vibration. The next day, the dealer called and advised I needed a front motor mount. I had them do it. I got the car back, and it still had the 3000-rpm vibration. I returned the car to the dealer, they re-replaced the DMF, and installed a clutch kit. Still, there was noticable vibration at 3000 rpm. The dealer has requested advice from their support, I've been without the car for 5 weeks, and I'm a little worried.

I have the same problem.

I've done all the tricks that are mentioned on the boards

1. New front motor mount

2. New flywheel (and clutch)

3. Optional exhaust bracket

And none has made any differance at all

From what I have seen on all forums, this is a common problem whithout solution

I have no more ideas how to get rid of this and do not want to spend a fortune at the dealer

[DANDAN]

If I were you guys I would stop trying to figure this out. I had a 2001 5 spd,which had a strong vibration at 3000 RPM's especially when decelerating. The dealer was unable to pinpoint this. I traded the car for a 2001 S which I still have. This car also has a hint of a vibration but to a much lesser extent. As far as I can tell most Boxsters I drove have this malady. I think it is perhaps a select group of owners like ourselves who are more in tune with the behavior and handling of our cars. My previous car was sold to a nice gent whom I spoke to, who has no issues with any vibration.

I drove my friends 2003 today and discovered a hint of vibration- he does not pick it up.

Bottom line is it is not really curable ( in my experience) and you could go nuts and broke trying to figure this out.

Hope this helps.

[pomocanthus]

Can someone please describe these vibrations; where they're coming from, where it is felt, any associated noise.

[rushrevisited]

Can someone please describe these vibrations; where they're coming from, where it is felt, any associated noise.

I would be happy to, because I am at a loss of what to do on this as well after reading the posts here and other areas as well. I am being told my dual mass flywheel is out of balance and it will cost $950 + labor to fix... Not sure if it is worth it if it may not fix the problem as someone has said here.

If I rev the engine in neutral, I feel a slight vibration between 3000 and 3200 RPMS.

If I am accelerating I feel it breifly in the same range too.

The BIG problem is when I am decelerating. If I am, for example, coming down from 5000 RPMS, I will hit 3,200 - 3000 range and it is almost random - sometimes absolutely nothing, sometimes it is the feel of a semi truck using his engine to break (same sound almost). It goes away by the time I hit 2900ish RPMS. My best description is a truck engine break.

Do you have any input or suggestions on this? They have check my engine moutns and say they are fine. They told me changing my spark plugs would fix it) paid them $760 for the 60,000 mile service 10000 miles early to have them changed thinking it would fix it - it didn't.

I am at a loss. I know my clutch needs to be replaced anyway, but to add $950 in parts to change the flywheel without knowing it will fix this bothers me...

My estimate from the dealer is $2980 for a new clutch, RMS (easy since they are in there already) and a new flywheel.

[pjslowik]

You should not feel the vibration, rather the resonance, you are experiencing. Something is imbalanced and you feel the resonance at the 3 - 3.3k range.

These engines are naturally balanced 360*/180*/6cyl. I'm sure Porsche goes to great lengths to fine-tune individual component balance too. They should be silky smooth.

I have had three engines in my 03. The first two were indeed silky smooth. After the third, I felt the same resonance you describe. Sometimes you might expect some increase in vibration after removing and replacing the flywheel/pressure plate. Things don't always get reassembled exactly the same. I expected to remove the transmission and reassemble everything myself, perhaps rotating it 180*, but I decided to pursue a warranty complaint. Dealer replaced DMF, clutch and pressure plate. DMF was shot - I can't understand why - 35K miles. This greatly reduced the resonance. Almost as smooth as the other two times. If it doesn't get worse, I'll be content.

When I get some spare time, I might remove the DMF and pressure plate, bolt them together, index it, and send it out to be balanced as an assembly. Some performance clutch mfgrs sell kits preindexed and balanced.

[lightrail]

Can someone please describe these vibrations; where they're coming from, where it is felt, any associated noise.

My '02 2.7 experienced a little mechanical vibration when deaccelerating from above 4200 rpm. The source was the drive train, and the vibration could be felt everywhere. I told my dealer about it during a 30k service. A tech drove it and diagnosed it as a bad DMF. I had the DMF replaced.

After the replacement, the car experienced mechanical vibration from the drive train everytime the tach hit 3000 rpm. It didn't matter whether the car was moving or not, I could rev the engine to 3000 rpm, and the vibration was present. When I talked with the service advisor about this, he placed his hand on the dash and revved the engine to 3000, then acknowledged the mechancal vibration.

The dealer then replaced a motor mount. -- No change, vibration still there, so

They pulled the transaxle and found the DFM they replaced was faulty ("flywheel will not return as per tech bulletin"). They re-replaced the DFM. (They also installed a clutch kit.) -- No change, vibration still there, so

They contacted Porsche tech support and performed several checks concerning the oil pressure relief valve and valve train. No problems anywhere. They compared like cars and found mine did not have the additional muffler support (the wire support shown as #6 in the diagram of this thread). The part number is 996-111-242-01.

With the repairs, as far as driving experience, I'm satisfied.

Porsche picked up the the costs. The dealer provided a loan car and was super.

Here's the parts list. Can anyone explain the "window adhesive"?

1 As Dual-Mass Flyw.

6 Screw M8 x 16

1 Clutch Repair Kit

8 Screw 10 x 50

7 Cyl Head Cup Seal

1 As Ignition Coil

2 ORMD-Window Adhesive (pn 000-043-203-73)

1 Exhaust Support

2 Hex.-HD Screw 8x25

2 Nut M8

1 Retaining Plate

2 Hed-Head Screw 8x30

[rushrevisited]

So are you saying the additional muffler support is what the final problem ended up being with the vibration?

[Tool Pants]

Can anyone explain the "window adhesive"?

It is a silicon sealant used for such things as the oil pan. When I saw it being used the mechanic told me it was also used for the windshield.

[lightrail]

So are you saying the additional muffler support is what the final problem ended up being with the vibration?

The vibration that occurred during acceleration went away when the DMF was replaced. (The dealer told me mine had a crack in it (?).) The vibration that occurred when the engine revved at about 3000 rpm was repaired by the additional muffler support.

[uabchris]

So are you saying the additional muffler support is what the final problem ended up being with the vibration?

The vibration that occurred during acceleration went away when the DMF was replaced. (The dealer told me mine had a crack in it (?).) The vibration that occurred when the engine revved at about 3000 rpm was repaired by the additional muffler support.

OK, explain this one. 00 Boxster, bought at 25 K with extreme 3000K vibration, replaced DMF...no change. Engine died at 95K, thats bad but at least I get rid of the vibration...yes and no. New engine(same DMF) was smooth as silk for the 1st 5K on the new engine then it cam e back but not quite as bad. So that rules out the exhaust bracket and all other drivetrain with wear. All Boxsters I have tried since have one form or another of a vibration except fot the S. I think the the engines have balance issues. I am driving mine until the wheels fall off...currently 149K.

[fasterjames]

I get the same vibration at 3000 rpm only when decellerating. I read on another post that this is a very common occurance. I had never heard of the muffler bracket before, I'm going to check mine this weekend. Thanks for the direction.

[UKCDC]

So are you saying the additional muffler support is what the final problem ended up being with the vibration?

The vibration that occurred during acceleration went away when the DMF was replaced. (The dealer told me mine had a crack in it (?).) The vibration that occurred when the engine revved at about 3000 rpm was repaired by the additional muffler support.

OK, explain this one. 00 Boxster, bought at 25 K with extreme 3000K vibration, replaced DMF...no change. Engine died at 95K, thats bad but at least I get rid of the vibration...yes and no. New engine(same DMF) was smooth as silk for the 1st 5K on the new engine then it cam e back but not quite as bad. So that rules out the exhaust bracket and all other drivetrain with wear. All Boxsters I have tried since have one form or another of a vibration except fot the S. I think the the engines have balance issues. I am driving mine until the wheels fall off...currently 149K.

[UKCDC]

I have a 2000 Boxster 2.7L Manual. Bought it with 71K on the clock and vibration at 3000 Rpm it was quite loud in gear out of gear accelerating braking always the same, since then replaced all motor mounts which dropped the noise to about 30% also later the water pump as this was starting to fail and contributing to the vibration noise. Now I have 77K and still the vibration, I have added the exhaust bracket with no affect. Garage says next think to try is the DMF $3000 and no guarantee it will work! Anyone any ideas? Spark Plugs, exhaust system, crank shaft bearing?

Edited September 27, 2007 by UKCDC

[david44tn]

I have a 2001 Boxster with the same symptoms as stated in the earlier posts. My vibration starts on acceleration around 3000-3200 in any gear and quickly goes away after the engine is out of this range. The vibration cannot be felt in the shifter or clutch pedal. It is very brief and can be felt through the seat, while accelerating during normal driving. When accelerating hard, the vibration is rarely felt (I suspect because the range passes by quickly). Deceleration is very different with the vibration much more pronounced in the exact same rpm range, and quickly goes away, starting around 3200 and gone under 3000 rpm, with any gear, although seems more pronounced in the lower gears. Some things to add. I have a new front motor mount. Also,the vibration cannot be felt with the vehicle stationary or rolling, with the transmission out of gear, clutch in or out with running the engine in the 3000-3200 rpm range. The vehicle has to be in an acceleration or deceleration (driving) situation in gear with the vibration to occur. I feel if I had a flywheel/clutch imbalance problem the vibration would be felt when the vehicle is stationary and reved to 3000-3200 rpm, it definitely doesn't happen then. I am now suspecting the rear/transmission motor mounts. I'm curious if anyone has replace theirs because of this vibration. Also to add, I haven't heard of anyone with a 996 with this problem, the dual mass flywheel/clutch is the same configuration, my thoughts are the difference of how the engine transmission assemblies are suspended comparing the Boxster and 996, maybe it doesn't occur in the 996. I would appreciate any thoughts to add to this. Thanks.

[catmanluge]

I have a 2001 Boxster with the same symptoms as stated in the earlier posts. My vibration starts on acceleration around 3000-3200 in any gear and quickly goes away after the engine is out of this range. The vibration cannot be felt in the shifter or clutch pedal. It is very brief and can be felt through the seat, while accelerating during normal driving. When accelerating hard, the vibration is rarely felt (I suspect because the range passes by quickly). Deceleration is very different with the vibration much more pronounced in the exact same rpm range, and quickly goes away, starting around 3200 and gone under 3000 rpm, with any gear, although seems more pronounced in the lower gears. Some things to add. I have a new front motor mount. Also,the vibration cannot be felt with the vehicle stationary or rolling, with the transmission out of gear, clutch in or out with running the engine in the 3000-3200 rpm range. The vehicle has to be in an acceleration or deceleration (driving) situation in gear with the vibration to occur. I feel if I had a flywheel/clutch imbalance problem the vibration would be felt when the vehicle is stationary and reved to 3000-3200 rpm, it definitely doesn't happen then. I am now suspecting the rear/transmission motor mounts. I'm curious if anyone has replace theirs because of this vibration. Also to add, I haven't heard of anyone with a 996 with this problem, the dual mass flywheel/clutch is the same configuration, my thoughts are the difference of how the engine transmission assemblies are suspended comparing the Boxster and 996, maybe it doesn't occur in the 996. I would appreciate any thoughts to add to this. Thanks.

I have had the same vibration on decelation at 3000 rpm. If you take off the muffler section of the exhaust it goes away. Placed an extra bracket on the muffler and it is still has the same vibration. It is something within the muffler itself on my Boxster...

[spongebob]

I have had the same vibration on decelation at 3000 rpm. If you take off the muffler section of the exhaust it goes away. Placed an extra bracket on the muffler and it is still has the same vibration. It is something within the muffler itself on my Boxster...

I have similar experiences. When I disconnected the muffler and made a test run the vibration was gone. I can't tell if it "drowned" in the exhaust noise or if there where a real differance.

But when I take my car out of winterhibernation next spring I will do some tests whith flexible exhaust pipe and try to hang the muffler direct in the bottom instead of the gearbox.

This is the step before a lightweightflywheel!

[david44tn]

This is very interesting and food for thought. At this point, since the complete exhaust system, muffler, cats, etc. are all suspended by the rear transmission/motor mounts, when removing the muffler some suspended weight is removed from the rear mounts. Maybe with soft or defective mounts, removing weight such as the muffler, will raise the rear of the engine/trans assembly up, keeping the mounts from being at a limit, therefore not transmitting a vibration? Just a thought.

[seafeye]

This is very interesting and food for thought. At this point, since the complete exhaust system, muffler, cats, etc. are all suspended by the rear transmission/motor mounts, when removing the muffler some suspended weight is removed from the rear mounts. Maybe with soft or defective mounts, removing weight such as the muffler, will raise the rear of the engine/trans assembly up, keeping the mounts from being at a limit, therefore not transmitting a vibration? Just a thought.

I have quite a vibration as well.

Replaced tires, brakes, wheel bearings and had a 4 wheel alignment. Still no difference at all. And i have the extra muffler support.

If i drive say 85mph, put the car into neutral i still have the vibration. So what do i try next?

[spongebob]

This is very interesting and food for thought. At this point, since the complete exhaust system, muffler, cats, etc. are all suspended by the rear transmission/motor mounts, when removing the muffler some suspended weight is removed from the rear mounts. Maybe with soft or defective mounts, removing weight such as the muffler, will raise the rear of the engine/trans assembly up, keeping the mounts from being at a limit, therefore not transmitting a vibration? Just a thought.

I have quite a vibration as well.

Replaced tires, brakes, wheel bearings and had a 4 wheel alignment. Still no difference at all. And i have the extra muffler support.

If i drive say 85mph, put the car into neutral i still have the vibration. So what do i try next?

This is not the 3krpm vibration discussed earlier in this thread.

Your problem is probably somewhere at the wheels.

Try a "roadforcebalancing" at a reputable tiredealer, it's a big differance compared to the standard balancing.It made a big differance on my car.

I bought new tires a while ago (Bridgestone RE050 something) and two of the tires where impossible to balance in the roadforce machine. The first time it said nothing in a regular balancing. But the tires had to be replaced at the end.

[RFM]

@ seafeye

Look at your wheel rims for deformations.