Autobox gone silly

[jonnyred]

Hi, I recently bought a 2001 xc70 with 150k on the clock, having only driven it for a total of 250 miles faultlessly, today it started dropping in and out of gear, when it wasn't doing this the change became clunky.

Has any body experienced similar or have any idea why this is happening?

Many thanks for any assistance...

[mikealder]

Have you checked the autobox fluid level with the yellow dipstick, best done with the unit up to temperature after a 20 to 30 mile drive using the side of the dipstick marked HOT, engine running.
Also when you check the fluid what colour is it and does it smell burnt - Mike

[Slackey]

Is it losing fluid? Could be the torque converter seal. I had exactly the same symptoms on an auto Granada about 15 years ago. I took a gamble and bought the car for a song guessing what it was and it cost me the princely sum of 49p for the seal and a few hours hard work removing the box, stripping it down and refitting.

Could be the seller topped up the fluid before the sale, it will run faultlessly until the level falls, which explains 250 miles trouble free.

[SonyVaio]

With the dropping in and out being described I would check the gearbox torque mount, you may well find it is in need of replacement, especially given age and mileage.

[jonnyred]

Thanks all and particularly Mike for the phone call.

Having slept the night dreaming about being dismantled the car woke in a much better frame of mind and did not repeat the same, instead it started to cut out first thing, but then had the foresight not carry on.

Box oil change and parts cleaning is my next mission.

Many thanks guys.

[mikealder]

I have sent you a PM with a few links in it that should be of interest, from our conversation I would tackle the car as follows:

1/ Check autobox fluid level and fluid condition, if blackened or burnt smell change the oil, if low top it up, remember only 200ML of fluid from min to max using the hot side of the dipstick and only use fluid that meets JWS3309 which can only be introduced to the box via the dipstick tube.

2/ Remove and clean out the inlet tract on the Electronic Throttle Motor as they can carbon up and stick causing rough idle, if the internal parts of the ETM have worn out then it can be repaired by a forum member based in London for around £100. Cleaning out the ETM is the best start point though.

3/ Check all the air pipes including the small bore hoses for cracks/ splits as an air leak on the inlet will also lead to lean mixture codes and can cause rough idle issues - Mike

[jonnyred]

Hi Mike I cant remember if you said the yellow sticker or the white sticker is the original part for the ETM? my one is yellow. Going to give it a go this weekend weather permiting.

Fluid level ok

Thanks for the link to the Canadian site, havent figured out how to order on it yet but will keep trying. As for the box behaviour whils I was away, it would appear its only clunking and droping out after a sustained run, probable because the fluid is hot and lost its viscosity, I hope.

Best regards Andy

[mikealder]

A white sticker on the ETM is the original unit, yellow sticker indicates it has been replaced, I would still consider removing the ETM and cleaning it out as they do suffer from carbon build up that makes the butterfly valve stick.

The fluid from Petro-Canada can be obtained from somewhere near Newcastle, I am sure if Andy (Thantoes) spots this he will let you know where it came from.

A regular fault with these boxes tends to be when changing from 3rd to 4th and it will drop 3rd but not catch 4th for a while leading to the engine revs increasing so when it does go in to 4th it does it with a bang, this could be the B4 servo cover within the box or it could be dirt within the solenoids causing them to stick - Mike

[jonnyred]

Thanks, I will give the ETM a bit of attention.

Its first and second that seem to be the only gears that are affected.

Lets see what happens after a clean through.

[jonnyred]

Not got round to doing the jobs yet, garage is now a bedroom and its to windy outside.

Had the Emission warning come on yesterday, put the ebay scanner on it and got PO172 rich bank 1.

If your reading this Mike, from searching the forum it would seem that the ECM that you have pinpointed could be the reason for this code, would you agree?

Thanks