Thread: Auto hunting at low revs - 6 weeks in the shop with no solution

thanks sierrafery the CC has been working, but does cause the hunting to go nuts. Will check the voltage on the brake switch as described tomorrow.

If that works out ok a full trans flush is worth a crack, thanks CaptainJack.

dont bother to measure anything related to the brake switch as long as the CC is working cos the fault with the NC contact of the switch would not let the CC work...it means your problem is somewhere else

just updating after my mega trans flush, today i was in the city most of the day driving around to various places. Absolute no more hunting. Gears are real smooth, the slight whine noise i used to have is dropped a lot.

I'm not saying this is your issue, but flushing my trans very thoroughly to make sure all new fluid is in the trans has made a huge difference. A bit expensive as you will waste some trans oil (i did 5 flushes and I'm sure some will say this is way overkill), but so far its not hunting and running very smooth indeed.

For those interested, I also had a ticking noise which i know is common. The car was running Castrol Magnatec 10w40. I did a full engine flush and have changed to Penrite HPR10 GAS (although im not running gas), because of its Zinc rating and the fact is is a 10w50 - so stays a little thicker when hot - and no more ticking - in fact the engine is running a lot quieter now. Checked my oil pressure and its come back up - it was a little low when hot using the Magnatec.

Good luck - hope you find the solution to the hunting issue in your box.

Low fluid levels will cause it, and there's a very specific method to filling the D2 auto. Not followed (in other words just doing what the workshop would normally do) will result in destruction of the gearbox. I know.

Finally sorted the Auto hunting issue.

Took the car to 3 auto specialists, two of whom wanted to reco the box for $5K (you could argue it's due, but not yet)

Took the car to a Rover mech who after 6 weeks parttime run out of time to pursue it.

Nearly sold it.

Then had another crack.

Borrowed a Hawkeye and noticed solenoids 1 and 2 were changing up and down with the hunting.

That's electrical! the auto ecu is sending commands.

The Auto Ecu was replaced by the rover guy so it must be getting bad data or something.

Pulled apart the console and run some resistance tests on the auto loom to the solenoids. (Not conclusive)

Nearly ready to give up.

Stuck my head under the car and noticed the loom that leads to the xyz switch and the transmission plug, was bent over the back of the transfer case (from memory)

Stuck my hand up there, scrunched it flat and slid it back in it's mount.

Took it for a drive, thinking that wouldn't have fixed it.

Bloody hell all fixed. (That was 2 weeks ago)

Now needs a section of the loom replaced.

What was happening?

There were no M&S lights, so the wires weren't shorting.

The auto would run ok when cold, but as soon as operating temperature was reached it would hunt and play up at low revs (sub 2000)

I'm thinking that maybe the signals in the two wires running from the output shaft sensor in the Auto to the Auto ecu, were getting scrambled a bit by the heat being applied to the loom where it bent over the corner of the transfer case.

Sound reasonable?

Thanks for all the input

Regards