Pressurised coolant tank? Low coolant warning...D3 V60😐

[BobModulin]

Hi folks, just signed up after buying a 2013 V60 D3 that appears to have an issue with a low coolant warning and a pressurised reservoir even when the engine is cold. Magic how it took a couple of weeks to rear it's ugly head! Paperwork shows it was a known issue that was cleared by resetting the engine code and topping up the coolant a couple of months previous. I wonder if a bottle of coolant repair sealant stuff was accidentally on purpose applied before sale...
My initial concern was with the engine overheating so I bought a Bluetooth obd dongle and use it with Carscanner to give live telemetry however both coolant and engine oil temps show approx 88 and 95 celsius respectively once up to temperature. Can I ignore the low coolant level so long as these sensors report these kind of temps and I keep topping up coolant from time to time or might the sensors give a false sense of security? I really can't be doing with a head gasket repair at the moment 🙈 I was hoping that in the 136hp state of tune the engine might be quite understressed and maybe have a bit of headroom for my strategy 🤣 Any thoughts? And is head gasket the likely culprit or might it be a turbo hose or something? Where else can the coolant get pressurised from? 🤔
Many thanks in advance 🙏

[Japster]

Is it the 5 cylinder D3 or the 4 Cylinder?

[Kev0607]

Originally Posted by BobModulin

Hi folks, just signed up after buying a 2013 V60 D3 that appears to have an issue with a low coolant warning and a pressurised reservoir even when the engine is cold. Magic how it took a couple of weeks to rear it's ugly head! Paperwork shows it was a known issue that was cleared by resetting the engine code and topping up the coolant a couple of months previous. I wonder if a bottle of coolant repair sealant stuff was accidentally on purpose applied before sale...
My initial concern was with the engine overheating so I bought a Bluetooth obd dongle and use it with Carscanner to give live telemetry however both coolant and engine oil temps show approx 88 and 95 celsius respectively once up to temperature. Can I ignore the low coolant level so long as these sensors report these kind of temps and I keep topping up coolant from time to time or might the sensors give a false sense of security? I really can't be doing with a head gasket repair at the moment 🙈 I was hoping that in the 136hp state of tune the engine might be quite understressed and maybe have a bit of headroom for my strategy 🤣 Any thoughts? And is head gasket the likely culprit or might it be a turbo hose or something? Where else can the coolant get pressurised from? 🤔
Many thanks in advance 🙏

I wouldn't ignore the low coolant level. Make sure there's coolant in the reservoir as a minimum until you get it fixed. Keep your eye on it.

The only real way to figure out what's going on is to pressure test the system. It could be anything from a split hose,a leaking thermostat, water pump or head gasket being the worst case scenario.

Might be time for a trip to the garage.

[Clan]

Originally Posted by Kev0607

I wouldn't ignore the low coolant level. Make sure there's coolant in the reservoir as a minimum until you get it fixed. Keep your eye on it.

The only real way to figure out what's going on is to pressure test the system. It could be anything from a split hose,a leaking thermostat, water pump or head gasket being the worst case scenario.

Might be time for a trip to the garage.

It wont be the water pump but most likely the radiator , a small drip from one of the lower corners. There should not be pressure in the system when cold though.

[Kev0607]

When you remove the radiator cap, is there any thick white residue on it that looks like mayonnaise or excessive clouds of white smoke as the car is running/accelerating?

If so, that can indicate a head gasket issue.

As Clan mentioned above, it could also be your radiator at fault.

[BobModulin]

Many thanks for your input. To answer your questions:

Kev / Clan: nope no mayo or smoke so that's something...as soon as I remove the cap the coolant level returns to normal after a hiss suggesting that the coolant is still there, just lower in the system which might explain why things aren't overheating on carscanner? Could the radiator add pressure since it's simply venting to atmospheric pressure? I hope it's something as simple as radiator or a hose...

Japster: it's the 5 pot and rather lovely it is too! Got the feel of a big engine...more 6 pot vibes than 4 pot vibes if that makes sense! 😊

Can the carscanner values be trusted in the meantime giving me confidence that I'm not catastrophically overheating anything? I had this issue first happen a couple of months ago, literally a fortnight into ownership but after venting and topping up it seemed to resolve itself for a while, only latterly giving me low coolant warnings under extreme braking / cornering situations. Incidentally on my current tank of fuel I stuck some BG245 in - is there a chance this would break down the seal created by liquid coolant repair, if it has been added? I wonder if my garage will be able to check if coolant repair was added before my ownership... 🤔

[Japster]

Originally Posted by BobModulin

Many thanks for your input. To answer your questions:

Japster: it's the 5 pot and rather lovely it is too! Got the feel of a big engine...more 6 pot vibes than 4 pot vibes if that makes sense! 😊

I asked this because I used to have a D4 5 pot V50 and it was a lovely engine, basically the same as yours with 177hp.

I had similar circumstances, pressure in the coolant system, turned out to be the head gasket. Can you smell exhaust fumes in the coolant?

[Kev0607]

Originally Posted by BobModulin

Many thanks for your input. To answer your questions:

Kev / Clan: nope no mayo or smoke so that's something...as soon as I remove the cap the coolant level returns to normal after a hiss suggesting that the coolant is still there, just lower in the system which might explain why things aren't overheating on carscanner? Could the radiator add pressure since it's simply venting to atmospheric pressure? I hope it's something as simple as radiator or a hose...

Japster: it's the 5 pot and rather lovely it is too! Got the feel of a big engine...more 6 pot vibes than 4 pot vibes if that makes sense! 😊

Can the carscanner values be trusted in the meantime giving me confidence that I'm not catastrophically overheating anything? I had this issue first happen a couple of months ago, literally a fortnight into ownership but after venting and topping up it seemed to resolve itself for a while, only latterly giving me low coolant warnings under extreme braking / cornering situations. Incidentally on my current tank of fuel I stuck some BG245 in - is there a chance this would break down the seal created by liquid coolant repair, if it has been added? I wonder if my garage will be able to check if coolant repair was added before my ownership... 🤔

The BG245 that you put in the fuel tank won't make a bit of difference to the coolant system. BG is for cleaning injectors... it has nothing to do with cooling.

It sounds to me like there's an air lock, possibly from a split hose or something. Really it needs checking out. You don't want to be driving it like this long term. Keep your eye on the coolant level in the engine and never let it get below minimum. For now, keep your eye on the car scanner app and the coolant level.

Ideally, it wants to be around around 90 degrees at idle and around 95 degrees when driving this time of year (those figures may be higher in the summer, but not now). If car scanner shows higher than that, you risk doing damage.

[pgoldi]

From my own experience, the pressurisation of the cooling system on first starting from cold is most likely the result of compression gases entering the cooling system through; head gasket, cracked cylinder liners or a combination of both.
A cylinder leakage test should show which.