Shaking when accelerating
#1
Shaking when accelerating
When cruising in comfort mode at 5th or 6th gear, if I press the paddle the car starts to accelerate but shakes pretty noticbaely. It feels like the engine is lugging because the transmission isn't downshifting and all that torque is just accelerating the car by force. I've done transmission resets, checked the selenoids etc. has any of you experience similar problems?
#3
#4
MBWorld Fanatic!
If you step down further so it actually downshifts, does it feel ok?
It does lug the engine at low rpms with light throttle, because it's more efficient and helps gas mileage. But you can easily override that with sport mode, or slightly more throttle.
It does lug the engine at low rpms with light throttle, because it's more efficient and helps gas mileage. But you can easily override that with sport mode, or slightly more throttle.
#5
yes if I press it hard enough it will downshift 2 gears, and the problem is very very rare in sport mode. It's just it gets annoying when trying to pass on highways
#7
Senior Member
When cruising in comfort mode at 5th or 6th gear, if I press the paddle the car starts to accelerate but shakes pretty noticbaely. It feels like the engine is lugging because the transmission isn't downshifting and all that torque is just accelerating the car by force. I've done transmission resets, checked the selenoids etc. has any of you experience similar problems?
Hope this helps.
Bill
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#8
When cruising in comfort mode at 5th or 6th gear, if I press the paddle the car starts to accelerate but shakes pretty noticbaely. It feels like the engine is lugging because the transmission isn't downshifting and all that torque is just accelerating the car by force. I've done transmission resets, checked the selenoids etc. has any of you experience similar problems?
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Bigg Willi (11-28-2023)
#11
#12
Update: after installing Weistec TCU - the issue disappeared completely. As a matter of fact, it even changed the car. The transmission is more fluent and much less harsh during normal driving, and much more aggressive and quick during aggressive driving. I now finally understand why TCU is one of most critical upgrades. Much recommended.
I haven’t measured acceleration differences, will do so when my BlackBoost intake arrives and is installed.
Are you modded or bone stock? I started having these issues only after ECU tune.
I haven’t measured acceleration differences, will do so when my BlackBoost intake arrives and is installed.
Are you modded or bone stock? I started having these issues only after ECU tune.
Last edited by GMBALL; 08-12-2022 at 09:06 AM.
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PiotrD (04-29-2023)
#13
Actually, I have to reverse my opinion. After many months of driving with this Weistec TCU and a lot of measuring of the acceleration times, all I can say - there is no improvement acceleration wise. It's literally the same. Maybe 5% at most, but that can be to elevation, outside temperature, small differences of the angle of the road, etc. I believe my positive opinion was based a very subjective feeling right after I've bought it. What it really did that it made shifting less harsh and much more fluent with a modded car and a high torque (1150NM). Other than that, don't expect what guys are saying here - that TCU tune is actually better than ECU tune and car with TCU tune is almost as fast as with an ECU tune. That is a total BS.
#15
MBWorld Fanatic!
Actually, I have to reverse my opinion. After many months of driving with this Weistec TCU and a lot of measuring of the acceleration times, all I can say - there is no improvement acceleration wise. It's literally the same. Maybe 5% at most, but that can be to elevation, outside temperature, small differences of the angle of the road, etc. I believe my positive opinion was based a very subjective feeling right after I've bought it. What it really did that it made shifting less harsh and much more fluent with a modded car and a high torque (1150NM). Other than that, don't expect what guys are saying here - that TCU tune is actually better than ECU tune and car with TCU tune is almost as fast as with an ECU tune. That is a total BS.
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chassis (05-08-2023)
#16
The Weistec TCU tune results in faster and more firm shifts. This is accomplished with faster target shift times and running higher line pressure which also has the added benefit of reducing slip and increasing the torque capacity of the transmission. With higher line pressure, the clutches in the transmission are clamped harder making for better grip which directly allows the transmission to hold more torque. With less slip and faster shifts, the lifespan of the transmission is typically improved as well.Key Features
- Faster Shifts
- Firmer Shifts
- Increased Line Pressure
- Increased Torque Capacity
#17
MBWorld Fanatic!
My understanding was that TCU increases torque limits in lower gears, where it is limited and thus allowing for a slightly better acceleration. At least, this is what Weistec says:
The Weistec TCU tune results in faster and more firm shifts. This is accomplished with faster target shift times and running higher line pressure which also has the added benefit of reducing slip and increasing the torque capacity of the transmission. With higher line pressure, the clutches in the transmission are clamped harder making for better grip which directly allows the transmission to hold more torque. With less slip and faster shifts, the lifespan of the transmission is typically improved as well.Key Features
The Weistec TCU tune results in faster and more firm shifts. This is accomplished with faster target shift times and running higher line pressure which also has the added benefit of reducing slip and increasing the torque capacity of the transmission. With higher line pressure, the clutches in the transmission are clamped harder making for better grip which directly allows the transmission to hold more torque. With less slip and faster shifts, the lifespan of the transmission is typically improved as well.Key Features
- Faster Shifts
- Firmer Shifts
- Increased Line Pressure
- Increased Torque Capacity
#18
Member
Mine does that too, feels like the transmission is hitting air bubbles in the fluid? Gonna try a trans update with the BenzNinja.
Now I know it's a Car issue.
Now I know it's a Car issue.
#19
Member
Yes Sir! Replaced the coils and plugs, and the shudders are completely gone, car is back to being just stupid fast and smooth. I really though it was the transmission, but I'm glad it wasn't. Already got more new plugs as they seem to last only about 40kmi, gonna get new coils too as you'll tear them up on removal. The joys of owning a super car..lol
#20
MBWorld Fanatic!
Guys.... Get ahold of Peter... AKA BenzNinja. Buy the computer, multiplexer and a membership. Have Peter give your car some software changes. He offers one that makes for an additional mode for the transmission (Sport +) that also changes how it behaves in sport. Before that my transmission was slow to downshift, would ‘thump’ a 2-3 shift and generally felt like it could be a lot better. Couldn’t be happier with the results. Be sure to also give it Intelligent Lighting. Another of those things not enabled due to our friends in government. He offers a long list of software changes and will gladly assist anytime you have an issue with the car. My car also got ‘remember last mode’ so I don’t have to disable Stop-Start every time I start the car.
#21
Junior Member
Yes Sir! Replaced the coils and plugs, and the shudders are completely gone, car is back to being just stupid fast and smooth. I really though it was the transmission, but I'm glad it wasn't. Already got more new plugs as they seem to last only about 40kmi, gonna get new coils too as you'll tear them up on removal. The joys of owning a super car..lol
#22
Member
In a word YES.. These engine are hard on plugs, I'd say change them every 40 - 60kmi. Also the Beru OE coils don't seem too robust, I switched to TRQ, they seemed to have addressed all of the OE coils faults. Bad O2 sensors can also cause our issue so that's next on my list. Good luck!
#23
Junior Member
In a word YES.. These engine are hard on plugs, I'd say change them every 40 - 60kmi. Also the Beru OE coils don't seem too robust, I switched to TRQ, they seemed to have addressed all of the OE coils faults. Bad O2 sensors can also cause our issue so that's next on my list. Good luck!
#24
Member
So the plug and coil replacement didn't fix your issue fully? I'd imagine a bad O2 sensor would throw a code a scanner would pick up, no? My current issue seemingly isn't throwing any relevant codes (transmission or engine). Also the car has 65k miles/104k km and I don't believe the plugs have been changed yet. I just bought the car and noticed the shaking on acceleration on the highway on the 3 hour drive home. It wasn't apparent to me on the test drive and the PPI i had done on at a MB dealer did not mention anything about it. Pretty concerned/angry to say the least.
Funny thing is, my CarFax said the plugs had been changed at 42kmi, but looking at them with now 60kmi I don't think they were. Change your plugs, it just can't hurt.
O2 = I had a 2003 G35, when I replaced all 4 O2 sensors one was completely broken off, it NEVER threw a code. O2 sensors can also get slow over time and not throw a code so I change mine every 60 - 70kmi.
Last edited by Bigg Willi; 10-23-2023 at 09:01 AM.
#25
Junior Member
Yes the coil and plug change did 100% fix my issue, just giving you what could be another cause of the issue with the O2 sensors.
Funny thing is, my CarFax said the plugs had been changed at 42kmi, but looking at them with now 60kmi I don't think they were. Change your plugs, it just can't hurt.
O2 = I had a 2003 G35, when I replaced all 4 O2 sensors one was completely broken off, it NEVER threw a code. O2 sensors can also get slow over time and not throw a code so I change mine every 60 - 70kmi.
Funny thing is, my CarFax said the plugs had been changed at 42kmi, but looking at them with now 60kmi I don't think they were. Change your plugs, it just can't hurt.
O2 = I had a 2003 G35, when I replaced all 4 O2 sensors one was completely broken off, it NEVER threw a code. O2 sensors can also get slow over time and not throw a code so I change mine every 60 - 70kmi.