Coolant leak, coolant level problems, coolant sensor warning

[rcx934]

Hi there!

There's a few issue with the cooling system on my 2003 2.8 Galaxy. I haven't had a chance to poke around the car yet as my garage isn't accessible but thought I'd get some info now so I know what I have to deal with when I get to have some garage time on the car.

There's a coolant leak. I can smell it, that smell of burnt coolant on the engine block. The previous owner (my brother) said he found a definite leak at the two sensors (photo below). He reckons it was leaking quite bad but then the leak reduced. I can now see signs of leaking around the sensors but nothing major. What are these sensors and do you think it's enough to replace the seals or must replace whole sensors?

The Check Engine light has come on and I'm getting code "P0116 Engine Coolant Temperature Circuit Range/Performance".

The coolant level when I open the reservoir is at max. But after driving the car it goes down to the bottom of the bottle. When I open the reservoir the level comes back up to the max mark!

There's also an idle issue. Car is fine when warm, but when cold the idle goes up and down every second, then steadies out.

Check engine light is giving error:



Position of leaking sensors:



Close up of leaking sensors:

[johnnyroper]

Do you get any excessive pressure build up in the expansion bottle after engine been run,does the pressure escape and then level comes back up again?

[rcx934]

after engine been run,does the pressure escape and then level comes back up again?

Yes, that.... after engine has run, if I open the coolant bottle, the pressure escapes and the level comes back up.

[johnnyroper]

I would get it checked for head gasket issues then.

[rcx934]

Any explanation of how a head gasket issue causes such symptoms?

[Chrispb]

Constantly running a car with coolant leaks and low levels of coolant will inevitably end with head gasket failure, you are asking for trouble using your car with constant leaks.

[johnnyroper]

The head gasket can cause combustion gasses to enter cooling system causing it to pressurise and push coolant level down in expansion bottle.

[rcx934]

Thanks for the tips. The coolant level has now gone down and stayed down.

I'm ordering factory manual and chemical sniff kit and clearing space to get the car into my garage.