D3 TDV6 revs hunting under light throttle

[winaje]

Hi all. My new-to-me D3 TDV6 hunts up and down the rev range by about 300RPM when under light throttle in traffic, and seems to make a light vibrating sound at the same time. I see the tacho needle cycling up and down about every 1.5 seconds, and feel the vehicle surging softly in time with it. Runs well otherwise, plenty of grunt etc.

Has anyone seen this?

[Rich84]

First thing to check is the level of your auto trans fluid. Plenty of info on here for how to do that - make sure you read it first. If that's good, next step is to try doing a double flush & replace filter/pan of the transmission. Plenty of info on here re: that too.


Failing that, your symptoms suggest a worn/damaged torque converter lockup clutch - very common on these cars (very heavy vehicle with a torquey diesel behind it) especially the ones used to tow very frequently. To be honest if your revs are cycling and fluid level is ok, worn TC is the usual culprit. You would want to take it to a specialist for firm diagnosis, who will probably tell you the whole trans needs refurb at around $6K, but many people have just replaced the TC and cured the symptoms.

[John58]

My 2007 D3 TDV6 was doing the same thing, most noticeable when the engine was cold. Haven't noticed it since the last service (which included an auto transmission service, i.e. replace trans fluid and adjust everything). My service agent (British Off Road) recommends a transmission service every 100 000km if the vehicle is being used for towing.
Cheers, John.

[Redback]

Hi all. My new-to-me D3 TDV6 hunts up and down the rev range by about 300RPM when under light throttle in traffic, and seems to make a light vibrating sound at the same time. I see the tacho needle cycling up and down about every 1.5 seconds, and feel the vehicle surging softly in time with it. Runs well otherwise, plenty of grunt etc.

Has anyone seen this?

Give it a major service Will, everything, I will say with all confidence the auto probably hasn't been done or if it has, probably only once, check to see if the steel pan is there, that will give an idea.

Baz.

[camel_landy]

I'd also suggest looking at the gearbox oil...

M