Strange problem - loosing 0.5 bar of pressure overnight - no loss of coolant or oil

[Frankncathy]

Lack of power at times in vr4 - pressure tested system and lost 0.5 bar of pressure overnight - when my hubby drives it the car throws coolant out - but since i have been driving it i have not lost any coolant or oil - temperature does not go above normal - boys in the garage said its definately headgasket - but surley it would be overheating and i would be loosing either oil or water? No creamy texture in oil cap - no leaks visable - its got the usual tapping noise from the engine that the prefacelift has. My main prob is it runs out of mot in september and i don't know whether to bother putting it through till i know what is causing it. It has been plugged onto diagnostic machine and no stored faults - its a real puzzler. I was advised to change the pressure cap on the radiator to a 1.3 bar instead of the standard 0.9 bar. Has anyone had a similar problem? I love this vr4 - its got the full leather and is a right stunner - its too good to end up as a doner car - but all the quotes i have had for headgasket are ridiculous and as i am not fully convinced that it is head gasket am reluctant to spend the money - i have heared of stuff to seal headgaskets - you add it to the system then build up pressure - but has anyone used this on a vr4 engine? As we are in sheepland wales its very hard to find anyone thats even heared of a vr4 never mind and experience of repairs - please help a damsel in distress that might end up loosing my vr4 on the 18th september!!!

[Wobble]

where in wales are you?

[Nick Mann]

I assume you are talking about losing pressure in the coolant system? I'm not sure how much loss becomes unhealthy, TBH.

There are a few people losing coolant recently, and I honestly suspect it is down to difficult (sometimes very difficult) to trace leaks in the system. Coolant pressure doesn't build, which means the boiling point of the coolant isn't raised, which means air bubbles forming and finding their way back to the expansion tank. In my honest opinion, the most likely cause is a small hole in a rubber hose or a slight crack in the radiator. The git is that these leaks can be VERY difficult to find, as the VR4 has water cooling to both turbos, the throttle body, the cars heater matrix, plus the hoses to the radiator. If you have someone who can pressure test the system, I'd be asking them to link out all the above and just pressure test the engine.

[Subaru ETA]

Did they TK test the engine?

[Oblivion]

I think Nick is right about a leak somewhere, a head gasket should have more of the symptoms you were looking for. I wouldnt put a 1.3 bar cap on, the plastic tanks on the radiator are more likely to crack at that pressure so go to something like a 1.1 if you really want to change it.

[Frankncathy]

thanks for the info i live in cardigan west wales dont know what a t k test is sorry

[Nutter_John]

Checks for hydro carbons in the water , dye turns colour if they are present