Not Impreza related this one, but I thought I would ask anyway.

My future father in-law has an old Subaru Legacy 4 door (Automatic), over the last couple of months it has developed a strange problem with water consumption.

It will loose 2 pints of water if driven on the motorway for 72 miles. On an average 20 mile run it will loose 1 pint. If driven everyday for 5 minutes or so, it will loose one pint of water over a week.

He has had it into the garage who have replaced the thermostat, pressurised the water system and found no leaks, checked out the head gasget which is fine, but the thing still looses vast amounts of water. The garage even claims that they have left the car running for one hour and found no drop in water level.

The car is not loosing oil or anything like that and runs like a dream.

Can anyone suggest any possible causes, the only thing we can think of is that the radiator cap is faulty and allows evaporation at speed.

Many thanks for any help.

Dave

Dave,

Not familiar with the Legacy, but I would guess that you're right regarding the pressure cap - if it were a head gasket your engine would have died by now - I presume the oil doesn't show any signs of water contamination (mayonnaise?).

If the garage tested the system they would have replaced the cap to pressurise the system, hence it may have seemed sound. Other than that, check the rad, hoses etc systematically, but replacing the pressure cap is a good (and cheap) place to start.

Rgds,

Alex

<BLOCKQUOTE><font size="1" face="Verdana, Arial">quote:<HR>Originally posted by david:
<B>Not Impreza related this one, but I thought I would ask anyway.

My future father in-law has an old Subaru Legacy 4 door (Automatic), over the last couple of months it has developed a strange problem with water consumption.

It will loose 2 pints of water if driven on the motorway for 72 miles. On an average 20 mile run it will loose 1 pint. If driven everyday for 5 minutes or so, it will loose one pint of water over a week.

He has had it into the garage who have replaced the thermostat, pressurised the water system and found no leaks, checked out the head gasget which is fine, but the thing still looses vast amounts of water. The garage even claims that they have left the car running for one hour and found no drop in water level.

The car is not loosing oil or anything like that and runs like a dream.

Can anyone suggest any possible causes, the only thing we can think of is that the radiator cap is faulty and allows evaporation at speed.

Many thanks for any help.

Dave[/quote]

Had a similar problem in a previous life
on 2.0 Gl manual Legacy
went through all the checks as you have
with no joy and a cylinder leak tester
(the one that changes colour when it
senses exhaust gases in the coolant)showed
up nothing eventually through fustration
pulled off both heads and found a leak between cyls no 2 and 4 on the right hand
bank. Maybe your last resort