grinding sound under load...

[porsche996tt_tpe]

My car is 2002 tt with tiptronic. On the 3rd or 4th gear, when RPM is slightly under 2000, when I hit the gas, I hear a short grinding sound underneath the car that lasts only about a second, otherwise the car goes just fine. When the engine is reving pass 2000RPM, this never happens. Or when the car is in 2nd gear, this doesn't seem to happen either.

Anyone knows what this grinding sound is??

Thanks.

[Sunnyside]

My car is 2002 tt with tiptronic. On the 3rd or 4th gear, when RPM is slightly under 2000, when I hit the gas, I hear a short grinding sound underneath the car that lasts only about a second, otherwise the car goes just fine. When the engine is reving pass 2000RPM, this never happens. Or when the car is in 2nd gear, this doesn't seem to happen either.

Anyone knows what this grinding sound is??

Thanks.

Apparently its a common thing to have and actually says a little bit about your driving style.

The TCU adapts to your driving style and if you have been driving the car in a very relaxed manor for an extended period the TCU adapts to that style. The way to stop having that grinding noise is to either have your adaption values reset ( disconnecting the battery does not do this). Or take the car for a very spirited drive for a lengthy period.

Don't ask my the nitty gritty info as to exactly why it does it but the TEC info says to reset adaption values!!

I have had similar and used my PST2 to reset the values, I do believe last time I checked that Durametrics can do that as well.

Apparently its nothing to get excited about.

:drive:

[700Turbo]

I have a similar issue.

you can view my thread here

http://www.6speedonline.com/forums/996-turbo-gt2/264174-bad-grinding-when-accelerate-up-3k.html

[Sunnyside]

I have a similar issue.

you can view my thread here

http://www.6speedonl...rate-up-3k.html

Is your Car a Tiptronic.......if not stop confusing the issue as Tips dont have light weight flywheels they have Torque Converters. I presume you are H8T WP on 6 speed and take it your car is a manual???

The OP has described a typical tiptronic trait and now has the Porsche remedy for that problem.

[Sunnyside]

This is what POSES Tek Info says: however just reset your adaption values.

Technical Information

© Dr. Ing. h.c. F. Porsche AG 18.11.2002 tu3052e.doc

Printed in Germany Page 1 of 1

911 Turbo

5/02

E 37013

After Sales

Tiptronic noises

Vehicle Type:

911 Turbo (996)

Model Year:

As of ’01 (1)

Equipment: Tiptronic transmission

Concerns:

Tiptronic control unit

Situation:

Driving noises/jerking during acceleration.

Grinding/rattling noise when accelerating from a standstill or when driving at low speed in third

gear (30 - 50 km/h).

Irregular/hard gear changes and jerking during acceleration also occur occasionally.

Information: The reason for this is the adaptation of the torque converter lockup clutch in the Tiptronic control

unit. If the vehicle is driven in a restrained manner or is frequently driven in stop-and-go traffic, the

Tiptronic control module adapts itself to unfavourable values that cause the aforementioned complaints.

This problem arises only if the car is driven in a comfortable/economical manner and not when it is

driven in a sporty manner.

Procedure: Install a new Tiptronic control unit with modified software.

Part Nos.:

996.618.180.04 New Tiptronic control unit

Introduction: 12th November 2002

99 Z3S 68 0865 RoW

99 53S 68 5844 USA

Procedure: 1 Install and code the new Tiptronic control unit, part No. 996.618.180.04, as described in the

Technical Manual, Group 3, Chapter 37 30 19.

2 Carry out a test drive, making sure that all upshift and downshift points are reached. Do not

switch the engine off after the test drive, but instead let it idle for 10 minutes. The adaptation

values will be written into the transmission control unit only after this time has elapsed.

Working Time:

37 30 55 06 Removing and installing control unit 130 TU

Includes: Removing and installing rear side-panel lining

Programming the control unit

References: 911 Turbo (996) Technical Manual, Group 3:

> Repairs: 37 30 19 - Removing and installing the Tiptronic control unit

[700Turbo]

I have a similar issue.

you can view my thread here

http://www.6speedonl...rate-up-3k.html

Is your Car a Tiptronic.......if not stop confusing the issue as Tips dont have light weight flywheels they have Torque Converters. I presume you are H8T WP on 6 speed and take it your car is a manual???

The OP has described a typical tiptronic trait and now has the Porsche remedy for that problem.

yup thats me :) and thanks for the clarification

[Sunnyside]

I have a similar issue.

you can view my thread here

http://www.6speedonl...rate-up-3k.html

Is your Car a Tiptronic.......if not stop confusing the issue as Tips dont have light weight flywheels they have Torque Converters. I presume you are H8T WP on 6 speed and take it your car is a manual???

The OP has described a typical tiptronic trait and now has the Porsche remedy for that problem.

yup thats me :) and thanks for the clarification

lol :thumbup:

[porsche996tt_tpe]

Thanks Sunnyside for the tip. I use the car as a daily driver, so stop-and-go is common in the city. Spirited drive is thing of a rarily as people here are equipped with in-car recorders and that they are happy to report to the police a Porsche-driver who does crazy moves... The mechanic told me that this is a problem with the Torque Converter and most people have this without fixing it.

I remember reading somewhere that resetting adaptation is turning the key to ON position without starting the engine for 60 sec??

Thanks.

d.

[Sunnyside]

Thanks Sunnyside for the tip. I use the car as a daily driver, so stop-and-go is common in the city. Spirited drive is thing of a rarily as people here are equipped with in-car recorders and that they are happy to report to the police a Porsche-driver who does crazy moves... The mechanic told me that this is a problem with the Torque Converter and most people have this without fixing it.

I remember reading somewhere that resetting adaptation is turning the key to ON position without starting the engine for 60 sec??

Thanks.

d.

No , I think you might be getting confused with the throttle adaption/calibration.

Get some one with a Durametric to reset them for you. Did you read the second post where I copied from the Porsche Tech Manual. That explains why you get the noise. However it says change the TCU.......But , resetting the values will also fix the problem. Of course, after an extended period of driving slowly again you will eventually get the problem back.

I would ask your OPC if your old TCU should have been changed for the the modded TCU before now FOC.

If you havent got a Durametric , I would strongly advise you to invest in one.

Edited January 5, 2012 by Sunnyside

[porsche996tt_tpe]

oh, ok. I'll take the car to the local mechanic and try to explain to him the problem and the fix. He's got a PIWIS and can probably reset TCU free of charge.

Thanks again.

d.

[porsche996tt_tpe]

Hi,

Just had TCU reset (Using PIWIS, Tiptronic>Reset Adapater Values), still had the grinding sound, but less and shorter in duration. I did carry out the test drive and 10-min idling instruction as above. I don't know if it's the test drive that wasn't aggressive enough or maybe the torque converter itself needs some sort of servicing. I've read a bit and understood somewhat about how torque converter and the lock-up clutch work; is there a serviceable part in the converter that require regular maintenance? I believe the grinding sound I'm describing is from the lockup clutch at the moment of contact?

This is just a bit annoying but otherwise fine without causing me additional problem.

Any comments? Thanks.

D.

[Sunnyside]

Hi,

Just had TCU reset (Using PIWIS, Tiptronic>Reset Adapater Values), still had the grinding sound, but less and shorter in duration. I did carry out the test drive and 10-min idling instruction as above. I don't know if it's the test drive that wasn't aggressive enough or maybe the torque converter itself needs some sort of servicing. I've read a bit and understood somewhat about how torque converter and the lock-up clutch work; is there a serviceable part in the converter that require regular maintenance? I believe the grinding sound I'm describing is from the lockup clutch at the moment of contact?

This is just a bit annoying but otherwise fine without causing me additional problem.

Any comments? Thanks.

D.

I reset mine not long ago and it hasn't come back, however the weather here has been truly awful so didn't get out for that long. Mind you, mine only did it when in too high a gear on a slope, drop down a cog before the auto shift down and it didn't make any noise under load.

In my extract from the Tech Manual, it does say replace the TCU for a later unit. Do you know if your TCU falls in the category of being the older type. Perhaps the change over has not been done and you still have the troublesome unit??

Just a thought.

[porsche996tt_tpe]

Car was mfg'd 7/2002, very close to the release of the .04 version, which according to above was 11/2002. Is the TCU difficult to get to? I'd make a visual of the sticker on the TCU. And also it has been silent for 15K miles since I owned it and only recently started to make that noise; this sort of weeds out TCU being the main (or only) culprit...

Reading the POSES again, my car didn't jerk under acceleration and didn't have the noise when moving from standstill. The noise only occurs momentarily on 3rd gear at low rpm (2000).

PIWIS did not give any error messages on the Tiptronic.

D.

[Adana996tt]

On 1/11/2012 at 9:10 PM, porsche996tt_tpe said:

Car was mfg'd 7/2002, very close to the release of the .04 version, which according to above was 11/2002. Is the TCU difficult to get to? I'd make a visual of the sticker on the TCU. And also it has been silent for 15K miles since I owned it and only recently started to make that noise; this sort of weeds out TCU being the main (or only) culprit...

Reading the POSES again, my car didn't jerk under acceleration and didn't have the noise when moving from standstill. The noise only occurs momentarily on 3rd gear at low rpm (2000).

PIWIS did not give any error messages on the Tiptronic.

D.

 

@porsche996tt_tpe did you find out the issue to this problem? I’m having exact same symptoms. Reset TCU w Durametric but still have slight grinding noise from the engine compartment when gradually accelerating. Actually occurs in 3rd and 5th gear and not while switching.