Sorted misfire on M50 525! Any suggestions please about bucking problem?

[Steve525]

I had a misfire problem on my 1992 525 with M50 engine(mainly when pullingaway at low revs). I replaced all 6 of the coil packs (they were the Zundspule type which are reported to give problems) with 6 second hand Bosch coils and the probem vanished instanty.
Now I wonder if anyone can help me with a "bucking" problem . This occurs when I am slowing down and take my foot off the "gas". If I hit the gas again the problem stops! The car is manual and is running perfectly otherwise and is well serviced on all routine things!
Thanks in advance for any suggestions!

[Kalevera]

Howdy Steve. Check the driveshaft/guibo/center support and flywheel/clutch. Also, see if you can replicate the symptoms by manually manipulating the throttle at the engine (without the car in gear/hood open) -- this will tell us if it's an engine problem or something further back in the drivetrain (more likely, I think).


best, whit

[632 Regal]

also check the engine and trans mounts..this has to be done manually by looking from under the car. Also check the rear end differentail mounts...any play can add to the "bucking"

[Randell]

i'm currently experiecing a similar type of 'buck' when i lift the off the gas, except mine is an auto... i suspect an incorrectly rebuilt torque converter, which along with my pretty tired driveshaft is causing a mild buck (just one, with maybe a second 'aftershock') upon throttle release

your clutch could be grabbing a bit like my TQ, and/or your driveshaft joints aren't flexing enough to take the pressure from the gearbox when you give it a rest

[632 Regal]

again check all the mounts and then go to the guibo and inspect,...simple stuff once you know where to look.