Surging and Jerking In Reverse 1st and 2nd

[bgidney]

Hello,

I have a 2003 996 manual transmission with 29,000 miles. I have brought the car into Beverly Hills Porsche several times and they tell me their diagnostics cannot find a problem with the car and they will not fix it if they cannot reproduce it. Which, of course, makes sense.

When I put the car in reverse or first, especially after having been parked for a few hours or more, it surges sometimes very violently. It does this only sporadically but at least every couple days and often many times on the same day. Sometimes it happens when in reverse and then again when put into first. Giving the car extra throttle even with my left foot completely off the clutch pedal usually does NOT help at all. The jerking is very violent and it will do this up to 5-6 times in a rapid succession of jerking. Is this the DME/egas software problem or is it the Variocam or is it something entirely different?

Incidentally, and I am unsure if this is related, I am intermittently getting very nasty gear grinding noise when going from 1st to 2nd and sometimes 2nd to 3rd. The noise is really unpleasant. When it happens taking the shifter back to neutral and then back into gear with clutch pedal still completely pushed down to floor does not help and I will continue to grind loudly each time I try to put it into gear without ever releasing the clutch. Finally, I am forced to put it in neutral, take my foot off the clutch, reengage the clutch, and it lets me get into gear. When merging onto the highway it can be pretty scary hearing the grinding and finding myself suddenly unable to accelerate stuck in neutral temporarily while I release and renegage clutch!

THANKS!

[Gator996]

How in the world are they unable to recreate that mess?

Why not leave the car with them for a week or two and ask them to drive it

everyday a couple of times?

[nycebo]

Your transmission sounds like it is fried, as well as the clutch. But if the service tech can't reproduce the problem, then ask him to accompany you while you drive the car around and point it out to him when it occurs. Perhaps you are just shifting incorrectly (I know, even if it's highly unlikely) and he could point out to you what you are doing wrong.

As an aside, you can always try another dealer. I can't imagine that Beverly Hills is going to have the most patient people. Here in New York, I drive the car 30 miles out of the city for service.

[rcg412]

Your transmission sounds like it is fried, as well as the clutch. But if the service tech can't reproduce the problem, then ask him to accompany you while you drive the car around and point it out to him when it occurs. Perhaps you are just shifting incorrectly (I know, even if it's highly unlikely) and he could point out to you what you are doing wrong.

As an aside, you can always try another dealer. I can't imagine that Beverly Hills is going to have the most patient people. Here in New York, I drive the car 30 miles out of the city for service.

Have the dealer or independent check the hydraulic slave cylinder for the clutch. I had this issue on another car, what happens is the hydraulic fluid (when the car is cold) is not as high as it should be, so the catch point on the clutch is very low (hence the violent jerking). Of course, after the car warmed up (and there was pressure in the system) it was fine. Being in beverly hills, I would gamble you realize it more when the temperature is real cold?

Agreed with nycebo... where do you take the car?

Edited December 29, 2005 by rcg412

[nycebo]

RCG412,

I go to Pepe Porsche in White Plains, NY. Have tried Manhattan Motorcars and New Country in Greenwich (which wasn't bad when it was independently owned) and they always seem to give me the runaround on service and screw me on pricing. That's what nice about Pepe: they're independently owned, the shop only services Porsche, and they handle my warranty needs. Maybe after warranty is up after two years, I'll try an indy, but frankly, Marc and John at Pepe have always been very responsive to my needs.

[viper501]

Have you considered cleaning the idle air control valve? Other vehicles of mine have experienced similar problems due to IAC not working properly due to contamination. Its a cheap and simple fix. Although, I'm not certain that the egas cars even have an IAC? Loren?

[Loren]

eGas cars do not have IAC - instead the throttle postioner opens the throttle butterfly just slightly at idle. It can get carbon'ed up too though.

[bbhelms]

Help! I am having this exact problem that Bagman describes in his first paragraph. As far as his second symptom, mine isn't really grinding as much, but the shifter as gotten more loose in the past day and it doesn't shift smoothly 1-2 and 2-3.

I'd like to know what the possibilities are before I take it in....

Did anyone find the outcome of Bagman's situation?

THANK YOU!

[Brian D. Barrett]

Hello,

I have a 2003 996 manual transmission with 29,000 miles. I have brought the car into Beverly Hills Porsche several times and they tell me their diagnostics cannot find a problem with the car and they will not fix it if they cannot reproduce it. Which, of course, makes sense.

When I put the car in reverse or first, especially after having been parked for a few hours or more, it surges sometimes very violently. It does this only sporadically but at least every couple days and often many times on the same day. Sometimes it happens when in reverse and then again when put into first. Giving the car extra throttle even with my left foot completely off the clutch pedal usually does NOT help at all. The jerking is very violent and it will do this up to 5-6 times in a rapid succession of jerking. Is this the DME/egas software problem or is it the Variocam or is it something entirely different?

Incidentally, and I am unsure if this is related, I am intermittently getting very nasty gear grinding noise when going from 1st to 2nd and sometimes 2nd to 3rd. The noise is really unpleasant. When it happens taking the shifter back to neutral and then back into gear with clutch pedal still completely pushed down to floor does not help and I will continue to grind loudly each time I try to put it into gear without ever releasing the clutch. Finally, I am forced to put it in neutral, take my foot off the clutch, reengage the clutch, and it lets me get into gear. When merging onto the highway it can be pretty scary hearing the grinding and finding myself suddenly unable to accelerate stuck in neutral temporarily while I release and renegage clutch!

THANKS!

May sound untechnical but I had this problem where you would start to go and the car would surge ahead and then jerk back almost like a bucking horse. Ended up being the springs on the throttle body and the gas pedal being weak and the cable would pull and then let some slack so your fut on the gas ended up making it go back and forth!

[bbhelms]

May sound untechnical but I had this problem where you would start to go and the car would surge ahead and then jerk back almost like a bucking horse. Ended up being the springs on the throttle body and the gas pedal being weak and the cable would pull and then let some slack so your fut on the gas ended up making it go back and forth!

Thanks for the info...I will have my shop check this out, along with the hydraulic slave cylinder for the clutch.

Any other ideas?