Misbehaving V70 Geartronic

[Phil Croxley]

Originally Posted by bananarama

Could this be a fluid flush of ~10-12L instead of a simple change of ~3-4L?

Sorry, I should have said, this is for a flush and software update.

[GrahamBrown1]

Originally Posted by Phil Croxley

Sorry, I should have said, this is for a flush and software update.

I think that price is pretty reasonable. They have men to pay at the end of the day!

[Kev0607]

Ahh, full flush... that's a good price. It would have been dear if it was just a sump dump though.

[Phil Croxley]

Originally Posted by Kev0607

Ahh, full flush... that's a good price. It would have been dear if it was just a sump dump though.

I thought that as the car has low mileage and I hope to keep it for as long as possible it makes sense to have it done this way.

[apersson850]

You symptom is down to each and every letter identical to the problem I had with my D5 from 2012. It had nothing to do with the gearbox at all. Instead the fault was with the TMAP sensor. That's a sensor that's mounted on the outlet from the intercooler, where it measures the temperature and pressure of the air fed into the manifold.

My particular TMAP sensor claimed there was a charge pressure even before the engine was started. When the sensor reported a higher charge pressure than really present, it doesn't want to increase the power output from the engiine, since it's already supercharging, or so it thinks. Not until you hit the floor, or nearly so, is the desired pressure higher than the falsely reported one, and only then does the injection increase.

The car's diagnostic system doesn't detect this, so you get no error codes. The good thing is that it's much cheaper than a troublesome gearbox. My car recovered completely after changing the sensor.

[Auldgit]

Originally Posted by apersson850

You symptom is down to each and every letter identical to the problem I had with my D5 from 2012. It had nothing to do with the gearbox at all. Instead the fault was with the TMAP sensor. That's a sensor that's mounted on the outlet from the intercooler, where it measures the temperature and pressure of the air fed into the manifold.

My particular TMAP sensor claimed there was a charge pressure even before the engine was started. When the sensor reported a higher charge pressure than really present, it doesn't want to increase the power output from the engiine, since it's already supercharging, or so it thinks. Not until you hit the floor, or nearly so, is the desired pressure higher than the falsely reported one, and only then does the injection increase.

The car's diagnostic system doesn't detect this, so you get no error codes. The good thing is that it's much cheaper than a troublesome gearbox. My car recovered completely after changing the sensor.

Very interesting. I took the car in to my dealer last Thursday, and his diagnosis was a faulty sensor in the turbocharger. This had shown up many times in the error codes apparently. Whether it's the only cause remains to be seen. They're also going to install upgrades for the engine and transmission so hopefully all that effort (and expense) will be rewarded.. I'm waiting now to get it back early next week, following which I'll update on results. Thanks. AG

[Rcdean]

Originally Posted by Auldgit

Very interesting. I took the car in to my dealer last Thursday, and his diagnosis was a faulty sensor in the turbocharger. This had shown up many times in the error codes apparently. Whether it's the only cause remains to be seen. They're also going to install upgrades for the engine and transmission so hopefully all that effort (and expense) will be rewarded.. I'm waiting now to get it back early next week, following which I'll update on results. Thanks. AG

I had similar symptoms with mine, lack of power sometimes when overtaking on the motorway.

Can't remember the exact codes but would read as overboost and underboost of the turbine at the same time.

This is the one I bought.

Bosch 0261230293 Pressure and... https://www.amazon.co.uk/dp/B0068M86...p_mob_ap_share

Not the easiest sensor to access, I used a 1/4 ratchet with many extensions to undo the torx.

Then coated my gloved hand in fairy liquid to squeeze down the cap to pull the sensor out

[apersson850]

Originally Posted by Rcdean

This is the one I bought.

That's the same kind of device as I replaced.
My car sometimes has problems keeping the speed constant on the road. It was really annoying to tow my 1700 kg caravan with it.
But replacing the sensor made it as new again.

There is a Technical Journal from Volvo saying that if the car is loosing performance for now obvious reason, without clear diagnostic codes pointing to the problem, they should try replacing the TMAP sensor first.

[Auldgit]

Originally Posted by apersson850

That's the same kind of device as I replaced.
My car sometimes has problems keeping the speed constant on the road. It was really annoying to tow my 1700 kg caravan with it.
But replacing the sensor made it as new again.

There is a Technical Journal from Volvo saying that if the car is loosing performance for now obvious reason, without clear diagnostic codes pointing to the problem, they should try replacing the TMAP sensor first.

Very useful. We'll see what next week brings... Thanks AG

[apersson850]

It should have been like this, but in this forum you can't correct mistakes unless you spot them immediately.

Originally Posted by apersson850

My car sometimes had problems keeping the speed constant on the road.