Storm losing water cruising

[frankie 0]

Hi when im cruising down the motorway bout 80mph the temperature gauge doesnt get above 70 degrees and the vr starts losing water. :( . In around a 150mile trip it will use around 3/4 litre of water. But when the cars sat in rush hour doing the same jounery and the temperature gauges gets around 90 degrees/when the fan cuts in it doesnt use any water at all. whats going on can anyone help?

[Dogzyboy 0]

I'd guess at leaky thermostat housing. Purely becasue I'm having similar problems (though loosing a lot less water) & I know that the leak is coming from the crackpipe to thermostat housing connection.

[Roger Blassberg 0]

If you are cruising on the motorway at say 3000rpm with the throttle only about a quarter open, there will be a relatively significant inlet pressure depression (manifold "vacuum") which may be sucking water into the engine via a leaking head gasket. When going around town, you are on the throttle a lot more so the manifold "vacuum" effect is not so pronounced.

 

Just a theory.

 

Is there any evidence of water or steam leaking externally?

 

Best wishes

 

RB

[frankie 0]

Head gaskets fine had the car at the garage to be checked, all pressure tested which came out ok, also the car had a new water pump from vw in may. No steam as far as i can see mate. Every now and again you can see afew drops ( and a do mean drops) tricle from the overflow from the expansion tank. Where abouts is the thermosat housing? Theres seems to be abit of water sitting on top of the gearbox wonder if it could be something to do with the housing leaking?

[Jon_vr6 1]

The top and bottom radiator hoses connect to the thermostat housing it its directly underneath either your dizzy cap or coilpack!(On a VR6)

[craigowl 0]

Here is pic of thermostat housing - circled in black and comprises three parts.

View is looking from front of engine with radiator and grill removed.

[frankie 0]

cheers fellas thanks for all the help will have a look at it tomorrow at work. :)