Joe_H
Well-Known Member
Hi all,
Finally ! - we got to the bottom of the oft' reported symptom of a quite heavy drive train vibration between 1700 and 2000 rpm (on an L series diesel)
There has been much talk on here and other places about egr valves / map sensors etc etc.
Some have found that removing the boost (turbo) from the circuit 'cures' the problem but also makes it as slow as a slow thing - yes, because you are reducing the torque. EGR (on an L series) reduces power especially if the egr is not 100%!) so 'replacing' a 'removed' egr will likely reduce power - hence torque - hence masking the issue.
As for MAF sensor - on an L series diesel, the MAF ONLY controls the egr - nothing else. so nothing at all to do with that if the egr is removed.
Well, here is what definitely cured mine.
NEW CLUTCH ! - the issue is clutch judder.
The L series develops max torque at about 2000 rpm. Any issues in the clutch will cause a judder that is felt through the whole drive train. With mine, I also had a leaking rear crank oil seal - which certainly didn't help matters clutch wise.
You could see the blue marks on the flywheel and cover plate. - the driven plate was in fairly good condition.
We fitted an OEM clutch and new rear oil seal and sleeve. 100% cured.
There was absolutely no evidence of clutch slippage at all.
Engine was out for a block leak at the back under the exhaust (core plugs changed) - so decided to have a quick gander at the clutch.. glad I did, the vibration was driving me crazy.
Hope it helps someone. ALWAYS use a quality clutch I think is a good adage. Also, any slight rear crank oil seal issue and your existing clutch is probably screwed. Usually, you would not know unless you check ! - if you have the dreaded heavy vibration in high gears from around 1700 to 2000 which then seems to clear above 2000 - I am 100% confident this will be your issue.
Joe
Finally ! - we got to the bottom of the oft' reported symptom of a quite heavy drive train vibration between 1700 and 2000 rpm (on an L series diesel)
There has been much talk on here and other places about egr valves / map sensors etc etc.
Some have found that removing the boost (turbo) from the circuit 'cures' the problem but also makes it as slow as a slow thing - yes, because you are reducing the torque. EGR (on an L series) reduces power especially if the egr is not 100%!) so 'replacing' a 'removed' egr will likely reduce power - hence torque - hence masking the issue.
As for MAF sensor - on an L series diesel, the MAF ONLY controls the egr - nothing else. so nothing at all to do with that if the egr is removed.
Well, here is what definitely cured mine.
NEW CLUTCH ! - the issue is clutch judder.
The L series develops max torque at about 2000 rpm. Any issues in the clutch will cause a judder that is felt through the whole drive train. With mine, I also had a leaking rear crank oil seal - which certainly didn't help matters clutch wise.
You could see the blue marks on the flywheel and cover plate. - the driven plate was in fairly good condition.
We fitted an OEM clutch and new rear oil seal and sleeve. 100% cured.
There was absolutely no evidence of clutch slippage at all.
Engine was out for a block leak at the back under the exhaust (core plugs changed) - so decided to have a quick gander at the clutch.. glad I did, the vibration was driving me crazy.
Hope it helps someone. ALWAYS use a quality clutch I think is a good adage. Also, any slight rear crank oil seal issue and your existing clutch is probably screwed. Usually, you would not know unless you check ! - if you have the dreaded heavy vibration in high gears from around 1700 to 2000 which then seems to clear above 2000 - I am 100% confident this will be your issue.
Joe
Last edited:
