We have had a long-term coolant problem with our car. It’s been going on for at least 18months now. It started with us losing coolant on long journeys. We don’t notice it when driving – it’s when we come back to the car after it’s cooled down that we get a ‘low coolant’ light on and signs of coolant having been blown out of the coolant tank.

Our garage (who we’ve used for years and trust) don’t know what the problam is but are suggesting that it might be a ‘slight’ head gasket problem pressurising the coolant system with exhaust gas and blowing it out of the pressure cap. Their view is that, as they don’t know exactly what’s wrong with it, they can try a number of fixes starting with the cheapest but that sooner or later we’re likely to find the gasket needs changing.

What I’m not sure about is whether it’s possible to have a long-term ‘slight’ head gasket problem. I thought head gasket problems got pretty bad pretty quickly. This has been going on for 18months (~15,000 miles).

Any views?

What model of car is it ? engine type etc?

It’s a 2002 Ford Galaxy 1.9TDi
(so a VW diesel engine)

It is possible to have long term head gasket problems, it will be a very small crack / gap that only allows a small amount of water passed if it was any more you would run dry and overheat leading to terminal damage. Garages can normally test for signs of exhaust gas in the coolant. Unless you can see a leak somewhere it does sound like the head gasket, might be worth a couple of the cheap options first header tank cap, thorough check of all hoses etc.

my VW engine had a similar thing, it was a 10quid flange leaking at the back of the engine block. Took ages to get bad enough to find it.
Required a full engine strip out to get at no doubt. I never got around to getting it fixed though.

Sounds like you have a small crack in the gasket or the head itself. Usually takes a long hard journey for these to show up, and still hard to pin it down 100%.
Only way to test is to get the garage to do a cylinder leakage test. Even then it may not show up. In the past I’ve left the tester in place and let it cook over night as it were. If you fill the expansion tank to the brim, any coolant on the floor the next day is a sure sign of cylinder head crack or gasket failure.

Alternatively, stick a tin of ‘block repair’ (or K-Seal) in the cooling system and see if that fixes it.

Hth
Marko

Yes.

I had an intermittent coolant loss (maybe twice a year) usually after a really long journey. Most cooling parts got replaced over about 2 years, only thing left according to my long term garage was a small leak in the head gasket. The cost to repair was more then the car was worth so I sold it at auction.

they can test the coolant to see if there’s any exhaust gases in it – would be my first test to see if it was the head gasket.

As above you can have long term ‘slight’ problems with the engine pressurising the coolant system and blowing it out past the pressure cap on the expansion bottle.

Other check used to be to put your hand over the exhaust pipe if the mositure on your hand smells of antifreeze then the engines sucking coolant into the cylinders.

Have they tested the coolant? They should be able to sample the coolant to look for combustion products in the water.

Thought my car had a head gasket issue but after the water test showed clear I looked harder, it turned out to be a faulty bleed screw before the heater matrix, after it was at operating temperature you could occasionally see water droplets on the bulkhead where it had squirted out.

My van also looses coolant occasionally, but I’m buggered if I can find the leak. If you’ve been topping up with plain water now is the time to pop down Halfords and get one of those testers with balls in a glass tube, you take a sample and it’ll tell you if your coolant is sufficient to prevent it freezing overnight. Mine is good to -13 as I’ve diluted it by topping up, so I’ll have to top up despite having not found the leak. Should be -37 at full strength.