XC70 D5 poor MPG

[Kev0607]

Originally Posted by lotuscorty

Looks to me to be a fair bit of work. It is a complete unit round the back of the engine, egr and related gubbins need to be removed to access. Unless someone knows any different??

Yes, I’d be intrigued to know. Thermostat replacement on earlier P2 models looked a doddle. I’m not sure about the euro 4’s though (2008 onwards), but I can’t find any videos on the job in hand.

[Tatsfield]

The later engines have a complete thermostat manifold which has to be replaced. The days of undoing three bolts, pulling out the old thermostat and replacing it with a cheaply bought new one are gone and it seems that Volvo do not expect you to routinely change the thermostat to ensure that it always is working at its best but to wait until it fails before getting involved with a lot of spannering.

[Kev0607]

Originally Posted by Tatsfield

The later engines have a complete thermostat manifold which has to be replaced. The days of undoing three bolts, pulling out the old thermostat and replacing it with a cheaply bought new one are gone and it seems that Volvo do not expect you to routinely change the thermostat to ensure that it always is working at its best but to wait until it fails before getting involved with a lot of spannering.

When you say ‘later engines’, what years do you mean? Or do you mean the P3 shape in general?

[Tatsfield]

I only speak from what I have read on the forum while worrying about the high cost of changing the thermostat on my 2012 XC70 which I would do routinely if it wasn't for the expense and great difficulty in doing myself. I don't know exactly when the change in design happened but it seems to go back as far as 2009. See this for information: https://www.volvoforums.org.uk/showthread.php?t=197671

[V70Zig]

Originally Posted by Kev0607

Yes, I’d be intrigued to know. Thermostat replacement on earlier P2 models looked a doddle. I’m not sure about the euro 4’s though (2008 onwards), but I can’t find any videos on the job in hand.

According to Vida replacement instructions it's a doddle on mine

But for lotuscorty it'll be a pain as yes the egr, throttle body, air box, battery etc have to be removed according to vida.........

The guy on here has some useful videos, sadly stat change isn't.....be cheeky and message him to do one....stat change that is.

[Kev0607]

Originally Posted by V70Zig

According to Vida replacement instructions it's a doddle on mine

But for lotuscorty it'll be a pain as yes the egr, throttle body, air box, battery etc have to be removed according to vida.........

The guy on here has some useful videos, sadly stat change isn't.....be cheeky and message him to do one....stat change that is.

Would you mind posting the Vida instructions?

[Kev0607]

When searching for the thermostat for my Dad's V70 P3 D5 (57 plate), it brings up the attached image as being the correct part. It looks like the one that's a pain to change?

My Dad's car is the same as yours V70Zig (No Polestar though, standard 185bhp D5). Its six months older, but its the facelift shape. Does this look like the correct part?

[V70Zig]

Originally Posted by Kev0607

When searching for the thermostat for my Dad's V70 P3 D5 (57 plate), it brings up the attached image as being the correct part. It looks like the one that's a pain to change?

My Dad's car is the same as yours V70Zig (No Polestar though, standard 185bhp D5). Its six months older, but its the facelift shape. Does this look like the correct part?

It does look the same as mine, you can get Vida without the Dice from the bay for as little as £1.49 and run it on your pc or less than a tenner if you want the disks.
It's a pain to print them from my lappy, scan and then upload to here so as a quicky here are just the pics....the only special tool is a 19mm deep socket to remove the sensor. Just follow the rad top hose it's front left hidden by the engine cover.

[Gazdkw]

Just to be clear, how do we know if it needs changing at all?

Its just a case of monitoring the coolant temp? I have a bluetooth reader attached to the car so it's pretty easy to read

[V70Zig]

Originally Posted by Kev0607

When searching for the thermostat for my Dad's V70 P3 D5 (57 plate), it brings up the attached image as being the correct part. It looks like the one that's a pain to change?

My Dad's car is the same as yours V70Zig (No Polestar though, standard 185bhp D5). Its six months older, but its the facelift shape. Does this look like the correct part?

D5 is just a badge denoting a 5 pot engine, there are engine variants for the D5 and might not be the same, putting the correct info into Vida should give you the right info.

Originally Posted by Gazdkw

Just to be clear, how do we know if it needs changing at all?

Its just a case of monitoring the coolant temp? I have a bluetooth reader attached to the car so it's pretty easy to read

I too have a bluetooth reader, because I don't have a temp gauge ! I have the torque and the car scanner apps on my phone to see actual temp.
From lotuscorty's posts it looks like his has unfortunately stuck in an open position which will fool the ecu into over fuelling.
Quickest way to to check without any apps or diagnostics connected is to start up from cold (overnight) and feel the top hose from rad to engine as it should remain a lot "cooler than the bottom hose" if it's getting warm after a couple or 3 min it's more than likely stuck open or partially open.

Welcome anybody's views on this post just in case I'm wrong....oh and there is a thanks button if I'm right...............