2003 2.9L Transmission problems - jatinder
My 2003 XC90 T6 started behaving strangely about 6 months ago (shortly after converting it to use LPG), and I received a Transmission Service Urgent warning message a few times. The car drove perfectly well with no further errors until about 2 months ago - when I noticed the transmission felt like it was slipping (no increase in road speed when the engine speed was increasing, and then finally the transmission engaging and the car would shoot off).

At this point, I received transmission service urgent warnings about once a week. The codes referred simply to "incorrect gear ratio". I had the car seen by Volvo who recommended a new gearbox (no surprise there 7-) and I contacted Volvo UK to see if they would help pay for the gearbox as they have done in the UK & throughout the world as my car had only done 61K miles. Their final offer was to give me a discount of about £1K on the £5K bill.

Since then, I've had the gearbox reconditioned at an independent transmission specialist for a total cost of £1600. They said that the gearbox had a sticky solenoid and that one of the clutch plates was worn down almost to nothing.

The car now drives well and the gear changes are smooth etc.

The only problem I now have is that the car doesn't seem to behave properly in certain instances as follows:

When driving at low speeds (<40mph) and I take my foot off the gas pedal, the engine revs drop down to about 600rpm, when I then press on the gas pedal again, the revs shoot up to say 1500rpm and the car accelerates properly and feels quite normal. If I press harder on the gas pedal, it kicks down as per normal.

When driving at slightly higher speeds (45-70), and I take my foot off the gas pedal, the engine revs stay the same or drop quite slowly. If I press on the gas pedal, then sometimes the car will immediately kick-down a gear and accelerate normally. Other times the engine revs will go up and the car accelerates normally.

Finally, sometimes the rev counter will go up say 200revs and immediately go back down again to where it was (like a spike/blip) and the car won't kick down or speed up. If I press harder on the gas pedal, then the car will begin to pick up speed or kick down and then accelerate. Whilst I'm pressing harder on the gas pedal, I can feel a slight vibration in the car. To get the car to kick down or feel as though it's accelerating, I sometimes have to press the gas pedal down quite far (if it was driving perfectly normally I'd be going at say 90mph by the time it kicks down or speeds up).

I've spoken to the transmission specialists about it and demonstrated it to them. Their response was that the gearbox and gas pedal were working correctly and that kick-downs were happening at the right revs etc. They said that my car just drove like that and there wasn't anything they could do about it.

Does anyone know what might be causing this?

I'm no mechanic - but it seems to me that either the kick-down is not happening correctly or that the gearbox/engine is not responding to the gas pedal position.

In either case, shouldn't the transmission specialist have noticed this (they test drove it for 100 miles before giving it back to me), and should they have fixed this as part of the gearbox reconditioning?

The transmission specialist has suggested that I drive the car for a few weeks and then get back to them if I'm still concerned. They've said that this problem won't damage or adversely affect the gearbox - but I'm not so sure.

Any info/help etc appreciated.