C6owners :: Forums :: C6 Support :: The Garage |
<< Previous thread | Next thread >>
|
2.7 hesitant vibration |
Please Register to enjoy additional Member Benefits |
Author | Post | ||
2ilent8cho |
|
||
Joined: May 11 2016
Member No: #2626
Location: Stoke on Trent |
Not really sure how to describe this but hopefully if somebody else has had this they will understand. I can be driving along at say a constant 45mph and the car feels shakey from the power, it feels like hesitation of engine power going on and off continually. If i go into manual mode and drop the car a gear it goes away. If i floor the car power comes on very smoothly and it this feeling goes away. The rev line's stay stable when its doing this shakey feeling so my gut is telling me its more to do with the gearbox than the engine. Is this sounding familiar to anyone else with a 2.7 V6 ? Car is currently on 109,000 miles and i see no sign of any gear box oil changes , could it be something as simple as needing a few changes? |
||
|
|||
C6Dave |
|
||
Member No: #1
Location: Northumberland |
Definitely worth giving a fluid change a try as it could be dirt in the fluid causing sticking in the valve chest. | ||
|
|
||
Hattershaun |
|
||
Joined: Dec 19 2010
Member No: #320
Location: Bedfordshire, UK |
It could also be the torque converter starting to break up. I've driven a C6 with this symptom. It was as if you were driving over a rumble strip at the edge of a motorway. |
||
|
|
||
2ilent8cho |
|
||
Joined: May 11 2016
Member No: #2626
Location: Stoke on Trent |
Yes it feels a little like that but without the noise. I get the feeling this might be expensive. | ||
|
|
||
arconell3 |
|
||
Joined: Jun 28 2012
Member No: #922
Location: Kalkar |
2ilent8cho wrote ... Not really sure how to describe this but hopefully if somebody else has had this they will understand. I can be driving along at say a constant 45mph and the car feels shakey from the power, it feels like hesitation of engine power going on and off continually. If i go into manual mode and drop the car a gear it goes away. If i floor the car power comes on very smoothly and it this feeling goes away. The rev line's stay stable when its doing this shakey feeling so my gut is telling me its more to do with the gearbox than the engine. Is this sounding familiar to anyone else with a 2.7 V6 ? Car is currently on 109,000 miles and i see no sign of any gear box oil changes , could it be something as simple as needing a few changes? You say the revs stay stable when this happens? That is somewhat strange, because in that case and without the car speed changing either, (I assume the cruise control is engaged) how can you tell there is a power hesitation? However, these power hesitations at just under 2000 RPM and at constant speed are well known. They are mostly caused by a dirty air intake tract (air filter, LMM's, butterfly housing). That causes a change in the power/RPM/accelerator-position matrix values being just outside the values acceptable by the gearbox controller, and resulting in a rhythmic opening and closing of the torque-converter lock-up. Clean or replace those parts and it should be OK again. Regards, Robert |
||
|
|
||
2ilent8cho |
|
||
Joined: May 11 2016
Member No: #2626
Location: Stoke on Trent |
arconell3 wrote ... 2ilent8cho wrote ... Not really sure how to describe this but hopefully if somebody else has had this they will understand. I can be driving along at say a constant 45mph and the car feels shakey from the power, it feels like hesitation of engine power going on and off continually. If i go into manual mode and drop the car a gear it goes away. If i floor the car power comes on very smoothly and it this feeling goes away. The rev line's stay stable when its doing this shakey feeling so my gut is telling me its more to do with the gearbox than the engine. Is this sounding familiar to anyone else with a 2.7 V6 ? Car is currently on 109,000 miles and i see no sign of any gear box oil changes , could it be something as simple as needing a few changes? You say the revs stay stable when this happens? That is somewhat strange, because in that case and without the car speed changing either, (I assume the cruise control is engaged) how can you tell there is a power hesitation? It just feels like engine power wanting to go forward then coming off, then back on, a bit like when you are about to stall in a manual how the power still lurches you forward but extremely subtle version of this. Its just one of those things thats hard to describe without feeling it. |
||
|
|
||
arconell3 |
|
||
Joined: Jun 28 2012
Member No: #922
Location: Kalkar |
Yes that describes the phenomena I was referring to pretty well. Except, as I mentioned, you would see the revs changing every time it happens, ever so slightly, but they do. Regards, Robert |
||
|
|
||
User Colour Key: Head Administrator, Administrator, C6 owner, Technical Expert, C6 Premier Discount Club |