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My car is 1996 EF Fairmont travelled 120ks.

It loses about 1 header tank of water per week but I cannot see any external leaks. There is no water in the oil and no puddles under the car when it is parked.

Do I assume head gasket?

Dean

From the "Ask Jack" archives - 14 December 2009

It is possible you have a head gasket problem but it needs to be confirmed before the cylinder head is removed.

Or at least, other possibilities are eliminated first.

A work colleague of mine had a similar model as yours with a similar problem and eventually found the heater core was the culprit. The water was running down the firewall and under the front carpet.

Garages have what is called a radiator pressure tester which as the name suggests,applies pressure to the cooling system in an effort to find water leaks.

This is a basic test most garages would apply first, to try and identify the cause of the water loss.

The other test you can do is remove the spark plugs after the engine has been warmed up and leave the vehicle to sit overnight. The next morning, have somebody crank the engine while you look for signs of water escaping from the spark plug holes, a sure sign of a head gasket problem.

Also have a good look around the manifold area. Sometimes engine block plugs (frost plugs) can leak and because of their location, the water can evaporate and not cause puddles under the car.

There are normally signs of water staining around the plugs if this is the case.

There are other tests available to garages which should confirm a head gasket problem. I would start with the above as the first steps.

One of the issues I have frequently found regarding cooling systems on older vehicles is; once a leak is found and repaired, pressure then gets applied to the next weakest link in the entire system. It is not uncommon to fix one leak and find a short time later another one has started.

It can be an ongoing nightmare at times as vehicles get older.

As an example my colleague fixed his heater core problem, and six months later his head gasket started to leak.