2003 Golf Mk4 BFQ engine Auto Tranny Excessive acceleration 1st and Reverse

[Bill1]

Hi folks. I need some advice please. When I put it in drive my car has recently started to shoot forwards, and sometimes backwards, frighteningly fast. It is extremely intermittent and seems worse from cold. It happens more often in 1st gear than in reverse. When you try to correct by letting up on the gas it creates a kangaroo effect like a learner in a manual car. Otherwise the car performs perfectly and the tick over is sweet as a nut. There are no fault codes or any other indications. Any ideas? Thanks in advance, Bill.

[itavaltalainen]

Checked ATF level?
If this is full enough you can try to get it flushed and refilled in a garage.

[Bill1]

Hi, thanks for your reply. Yes, I had the ATF flushed and refilled but, if anything, the problem has got a bit worse (less intermittent). I have a horrible thought that it is going to be expensive to fix.

[itavaltalainen]

I would take it to an automatic gearbox specialist.

[Bill1]

Yes but in Cyprus the "Specialist" is the guy with the largest lump hammer.

[Bill1]

Some good news on this. After closer inspection found that the ATF cooler had been bypassed. This suggested that sometime in the past the cooler failed and caused ATF and G12 to mix. Replaced the ATF cooler and routed the coolant pipes properly, flushed the ATF and replaced the filter and all is now good as new. It is possible the G12 in the ATF might have caused some damage to the transmission which may shorten its life but, for now, I'm happy to have the old girl safe and driveable again.