Odd sensation of being "nudged along" (200TDi Auto)

[John_R]

If I drive along at a steady 50MPH, throttle held steady also, I get this weird feeling of a kind of nudging sensation, or of being pushed along in short shoves.

The 200TDi engine note never falters, nor do the revs on the counter appear to shift at all. If I drop down out of Drive into 3 the effect seems to stop, but I wonder if that is just because the throttle has to held wider open, revs higher etc. and maybe I should test to see if it happens somewhere else in the rev range in that gear.

It is a very odd feeling though, like a push-me-pull-you effect.

Mileage is high at 178000, so lots of things could be worn. I do get transmission whine as I get up to 25/30 MPH which rises in pitch a little before all the other noises drown it out.

Any clues as to where I should be looking?

[TEMPL4R]

First thing,check the level in the box.

Then try to drive as a Manual, go through the gears yourself and see if it still does it.

If it holds OK, it might want a clean out in the valve block and pick up filter.

Chris

[FALCON]

The over-drive kicks in at 50MPH on my V8 - its a noticeable event when the disco starts to slow and the overdrive switches back to 4th. Does the kick down work ok ?? ;)

[Widget]

The torque converter should lock at that speed to supply straight-through drive. Is it possible that it could be engaging and disengaging giivng the feeling you describe?

Just a thought - I'm no expert.:D

[John_R]

Thanks all for your help so far. :)

This has been happening all the time I owned the car (since October) and has not changed after having the gearbox fluid and filter changed.

Kickdown works just fine.

I had just yesterday begun to wonder in my own mind about lockup, so maybe widget has the right idea.

I have tried driving like a manual, and when I do that I do not get this happening, howver there is no harm in further study.

I have driven a few automatics over the years, and never really noticed when lockup occurs. Perhaps, as those other cars were all much later, newer models the effect was too subtle to feel.

[NomadABC]

My last auto Tdi definitely gave a nudge as it locked up at 53MPH. Is this what you are describing?

[John_R]

Nomad, that's what I am hoping to figure out! :)

If I drive as described in the root message, and definately at 50, not 53, I get the "nudge" over and over again. I guess the frequency is every few seconds, not that regular though. So maybe one nudge, then another within two seconds, then a gap of four seconds, then two nudges in quick succession.... pretty random but never long between them.

I am stuck on site work-wise now for a little while, so cannot go for another test-drive, but this lock-up idea does seem favourite so far.

That in itself could be comforting, as surely this is not a fault, just a case of driving just on the point where it wants to and it is locking and dropping out again... maybe...

[Widget]

If I drive ... at 50, not 53,

The lock-up speed will differ between cars because of gearbox construction tolernaces and wear. Tyre circumferences will be different also - and make an allowance for tyre wear and speedos.

[NomadABC]

If I was to drive at 53MPH and hold it at that speed on the flat, the box would lock and unlock all the time. If your starts at 50MPH and then stops as your speed increases then it's simply the torque converter locking up. Likewise if you hover around 50MPH then it will do as mine did. This is the drivetrain doing as it should. Don't worry.

[Cannonball Bob]

As an aside my 300TDi manual suffered the same symptom. One damn good engine service later and it's silky smooth again. Possibly clogged up injectors and valve clearances contributing to the nudging?

[John_R]

Thanks everyone, this really does sound like the best explanation for what I have been experiencing.

What really shows it up is a long stretch of the A3 near home, which is posted to 50MPH speed limit with a good few GATSOs.

Now to get on with the rest of the faults! :)

[QUINN]

This sound s like mine was doing it felt like i was towing checked everything found nowt , but next day the bottom intercooler hose blew off , new jubilee clip and been fine since if thats any help

[freelanderPX54]

Tis the hand of god thanking you for buying a Landrover