General: Low coolant level in V70

[kev27]

Hi
Any help/advise will be appreciated.

I have a V70 2015 diesel estate.

For quite some time the coolant level drops below the min level after just 150 miles or so.
I top up the header tank to max... all OK travel a few miles ( 50 or so ) anf I get the coolant level low warning on the dash.

After another 100 or so I then get a message to turn off engine... When I check the level it is below the minimum.

I had the car at a Volvo specialist who visually checked everything and did a pressure test for a few hours that showed there was no leaks anywhere.

He checked everything he could think of and found no faults so why is the coolant level dropping all the time?

Thanks

kevin

[cheshired5]

Pressure testing doesn't test the expansion cap so either replace that or at least flip the seal in the cap to establish a better seal.

[ASt85]

Originally Posted by cheshired5

Pressure testing doesn't test the expansion cap so either replace that or at least flip the seal in the cap to establish a better seal.

99times out of a hundred the expansion cap seal is the culprit.

However, it is also worth checking the seals on the heater matrix inside the cab - look for white greenish/blue track lines from the LHS of the where the tubes join to the matrix on the lower left plastic console ie the passenger side of "transmission" tunnel near the hot air outlet.

Lift the rubber mat on the passenger side - the rate of leak is slow so the surface of the carpet doesn't get wet but will feel slippery to the touch - if you lift the carpet and you may well find a green/blueish stain on the underlay.

[ITSv40]

The OP would be better posting in the correct forum for his model year. There may be something pertinent to that particular model.

[turboboy]

A leak test is usually carried out by removing the expansion cap and screwing on a pressure pump / gauge adapter in its place.

My money would therefore be on the cap seal or the cap itself. Worth trying turning the seal over as Cheshired5 suggests. At least this will not cost anything.

[Derek UK]

If the cap is bad it should show signs of coolant on top of the tank. Cracks in these coolant tanks aren't unusual and I would take out the tank and check it out. My 2000 V70 tank had a crack in the top when I bought it and was given a new one. I promptly broke the sender due to the wires coming adrift. 😒

[turboboy]

Few years ago I had a very reliable and well maintained Renault that suddenly started losing coolant.

Could not find a leak and there was no indication of any staining. One day I opened the bonnet with the engine running and fully up to temperature after a long run and saw a very fine jet of coolant coming from a pinhole in the middle of one of the (fairly new) radiator hoses. Once the engine was switched off the leak stopped quite rapidly, with no indication that there had been a leak.

Further investigation showed the loss was only when the engine was fully hot with the engine running. Because the coolant was hot and not dribbling it left no trace as it evaporated before it landed anywhere.

[Clan]

Originally Posted by turboboy

Few years ago I had a very reliable and well maintained Renault that suddenly started losing coolant.

Could not find a leak and there was no indication of any staining. One day I opened the bonnet with the engine running and fully up to temperature after a long run and saw a very fine jet of coolant coming from a pinhole in the middle of one of the (fairly new) radiator hoses. Once the engine was switched off the leak stopped quite rapidly, with no indication that there had been a leak.

Further investigation showed the loss was only when the engine was fully hot with the engine running. Because the coolant was hot and not dribbling it left no trace as it evaporated before it landed anywhere.

Volvo coolant is designed to leave a white/green stain around any leaks .

First place i would look is the lower end of the radiator side tanks , bottom corners ... for dampness or stains .

[Derek UK]

Originally Posted by Derek UK

If the cap is bad it should show signs of coolant on top of the tank. Cracks in these coolant tanks aren't unusual and I would take out the tank and check it out. My 2000 V70 tank had a crack in the top when I bought it and was given a new one. I promptly broke the sender due to the wires coming adrift. 😒

Forgot to also say that I had a new rad fitted last week due the old one leaking along the bottom edge. Long periods of sitting around during lock down probably didn't help. Remove the front under tray to check. Just a 10mm bolt each end and easy to do.

[RollingThunder]

Not sure which coolant reservoir you have, but the one shared by the 850 and phase 1 x70s have a design fault, whereby the reservoir's connection to the thermostat housing hose is subject to vibration stress and often cracks causing mysterious coolant loss... see pic for detail.