suspected head gasket

[casperdog21]

I have had a few problems with over heating, not bad but its not right, losing small amount of water every couple of days, but checking her over today when I took the oil filler cap off there seems to be steam chuffing out of the filler hole, I think its the head but I just want to check cheers

[T-Cut]

When the engine's stone cold, do you notice any pressure released when you unscrew the coolant filler cap?

TC

[kaiser]

First check the fan!

[casperdog21]

the fans etc are all good, new thermostat but even at over 100 degrees it wont open, Ill check pressure later when it gets cold, but it seems a lot of back pressure, she runs on gas and its that cheap to run I dont want to get rid,

[DMGRS]

It could be many things, but I have to be honest - it doesn't sound like Head Gasket Failure.

Coolant cap can cause the loss of coolant, thermostat being stuck or slightly stick can cause high temps - as can a non-working cooling fan.

[Ratty]

What engine have you? the 1.8 fan will not come on until 105 degrees .

[freck]

Is there an airlock around the thermostat? You say the temp gets to 100 and the thermostat isn't opening, I take it the rad isn't getting hot?
Did you fit the thermostat yourself or a garage?
I'd be taking it back if it was a garage before you really do have a HGF :eek:

[SD1too]

... when I took the oil filler cap off there seems to be steam chuffing out of the filler hole ..
Is it steam or is it oil vapour? "Chuffing" usually means cylinder wall "blow by" I'm sorry to say.
... new thermostat but even at over 100 degrees it wont open ..
How do you know that it isn't opening? Monitor the temperature using the instrument pack diagnostics and when it reaches 90° feel the bottom radiator hose. It should be hot.

If a garage has been working on the cooling system then they probably haven't filled and bled it properly resulting in an air lock.

Did they, or anyone else, put K-seal in it?

Simon

[kaiser]

And it is not a case of overfilling?
It would be good with model engine, and also the actual temperatures you see.

You know the gauge is totally useless?

[casperdog21]

thanks for the replies the car is a 1.8, you can go for a run and all seems well then up the temp goes 104 the fans cut in ok sometimes it can go higher but not for long, when you feel the thermostat one side is red hot and the bottom rad hose is cold and with that temp the stat should be opening, theres a few threads on the forum with the same thing looks like a stripdown, there was a bit of pressure release when you open the cap

[trikey]

thanks for the replies the car is a 1.8, you can go for a run and all seems well then up the temp goes 104 the fans cut in ok sometimes it can go higher but not for long, when you feel the thermostat one side is red hot and the bottom rad hose is cold and with that temp the stat should be opening, theres a few threads on the forum with the same thing looks like a stripdown, there was a bit of pressure release when you open the cap

If the hose is cold, its an airlock, dont strip anything just yet!

[kaiser]

thanks for the replies the car is a 1.8, you can go for a run and all seems well then up the temp goes 104 the fans cut in ok sometimes it can go higher but not for long, when you feel the thermostat one side is red hot and the bottom rad hose is cold and with that temp the stat should be opening, theres a few threads on the forum with the same thing looks like a stripdown, there was a bit of pressure release when you open the cap

That all sounds pretty normal to me, for town driving. But maybe a stuck thermostat?
Only thing is the pressure when cold, that should not be there.
Stone cold??

I have a 1.8T, and there is a lot of pressure on the oil filler cap. If lying loose on top, the back pressure will lift it clear! I have not experience with the normally aspirated unit (non turbo).

[planenut]

Casperdog, have a look at my posting

http://www.the75andztclub.co.uk/forum/showthread.php?t=214856

The temperature/coolant sensor was less than £8, and there is no need to drain the system to swap it, with slight loss of fluid only.