Lag and knock on acceleration

[Paul33]

Hi Guys,
I recently brought a 2012 XC60 (D4) - 100k miles (just over) - and it was great until about an hour ago.

When I stop at lights, I press the accelerator, nothing happens and then about a second later it's like the gearbox has decided that it's alive again and it accelerates off (normal performance).
When the gear box decides to start doing something there's a clunk (it's really like the gear box spun up and suddenly got to a biting point).

I do not have the solenoid problem of slowing down, dropping down gears and then accelerating to cause the clunk - it really is only when I come to a complete stop (on the flat or hill, it's the same everywhere).

I don't know how to check the gearbox oil on this car (as there's no dipstick) and I'm new to this model.

Any ideas what it could be or what I can do to further diagnose the issue?

I'm about to go for the large service (new cam belt and water pump) on Monday - but I don't think that this is related to the current issue.

Thanks in advance,
Paul.

[Adrian B]

First make sure your battery is fully charged.. It's virtually free to do. No fault messages showing on clocks one hopes!
My car is a 2012 D5 manual. I had the same recently when gently pressing the accelerator in 5th and 6th gears.
I have been doing small trips for the last 2 months all under 15miles!
Today I bit the bullet, got on the motorway for 30 mins with cruise control on!
Dpf sensors must have done a recirc and reset sommat. Problem solved for now. Let's see!
Having said all that the systems on these cars do have gremlins from time to time! that come and go with no reason.

[Paul33]

Hey Adrian,
thanks for the response.

I had the problem after a 200 mile motorway trip.
However, I took the car out to try and make sure exactly when the problem happened and didn't - and I couldn't get it to happen again.

and I tried for about an hour (including motorway time).

At least that means I can rule out the engine mounts as the source of the clunk (glass half full right).
It also proves it can't be the solenoid (I had that before and it does not go away).

I'm driving into the mountains tomorrow morning - so lets see if it happens then.....

I really hate miracle fixes.
If I manage to create the issue again or diagnoses it I'll post it here.

Or if the car is wedged into a mountain side tomorrow I'll post a picture :-)

and thanks again,
Paul.

[The Thong]

Before you go any further, is your software up to date on the motor? Has the box ever been serviced? Get it linked to diagnostics and get the box reset. The TF80 has a few gremlins that can be fixed and some that can’t. You’ll be amazed what an oil change and reset can do. But….. diagnostics first.
Good luck.

TT