Thread: D2 TD5 Autobox diagnosis

I wouldn't rule temperature out just yet. Plotting the temp fields against speed fields and manifold turbo pressure, shows that the pattern you are concerned about occurs during the warm-up period and disappears once once the coolant temp (Brown line) has stabilized. (Note Y axis is logged and gaps in road speed are zero values).



I'm not full bottle on Auto transmissions or Turbos, but could it possibly be engine related or and an electrical comm issue rather than transmission???

Another idea is to log the data over the same route with the engine warmed up first.

Cheers

Steve

Pretty level, no discernable gradient.
I can't imagine getting the test without being in the warm up stage to some extent, just idling would take forever to get there.
There is a chicken and egg as well on some of that, if you replicate the revs, say go for a drive and keep it in second (I reckon that would give you 3000 for 60kmh) then the engine will be heating up.
I can actully stop this from happenning by just stopping and letting it work through the gears again, or by manuually changing to force a bit more action in the box.
I reckon I might try and ping Dave or his son over on LR4X4 to see if he has a definitive diagnosis.

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steve_a,

Is Rok_Dr's plots and analysis fair and consistent with your experience? That points to engine temp determining if the gearbox should go into lock or not. What other diagnosis are you looking for?

Originally Posted by slug_burner

steve_a,

Is Rok_Dr's plots and analysis fair and consistent with your experience? That points to engine temp determining if the gearbox should go into lock or not. What other diagnosis are you looking for?

Not really, the period of time/speed is not when lock is expected and I wasn't looking for it to lock, it's only 60kmh. I made a point on the way home last night of running the car is the first few seconds to a higher rpm in 1,2,3 and also coming to virtually a complete stop.
The same stretch then saw it behave and do the expected 2000rpm after that even though the engine would have been at the same temp.
This just points to hydraulic pressure to me, so crap in the solenoid seals or similar.
It may be that there is more than one issue, e.g. poor oil pump, worn clutches which makes a diagnosis tricky due to interactions.

Electrical issues are tricky, if it only happened in the wet say then I'd be thinking that maybe it is a loom issue, but nothing is pointing me that way at the moment.
Engine issue, not this fault, though I do wonder if it is putting out 100% power, my tuned-up-a-bit 300tdi would seem to give it a good run for it's money, till it runs out of gearbox


I was hoping (as in first post) that someone knew which area(s) of the box were the likely cause so I could see if triage or full fix was the way to go.

For once the Rover was helpful and did the same thing on the way in to work on the same stretch as out. Not as pronounced, but was accompanied by a surgeing feeling, it was like clutch slip in a manual but was oscillating.
Also accompanied by ATF smell. On checking, it had spat some fluid out of the dipstick (I added one a few months back).
Level is about right and the dipstick is the only source of ATF I can see.

So, more evidence for hydro but no idea of actual cause...

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On the plus side it has had lots of new fluid..., I flushed the cooler a few weeks ago and I did the filter as well before the pipe failure.

I am wondering if you have crushed/misplaced the o rings that connect the filter to the valve body and it is leaking. Spitting up the filler tube suggests that the fluid is getting back into the sump but not being sucked out.

It may be worth a look before you go spending big money.

I think you would have more than one symptom like flaring changes, slow engagement, etc if there was something mechanically wrong. Sometimes the best course of action is to relook at things you have recently touched.
Regards Philip A