Coolant Pressure?

[JLSTDI]

Banging my head against a brick wall with this one!

After long (and now it is colder short drives) and then leaving the car with engine off, the coolant is going down. When I next start the car the "STOP - CHECK COOLANT" is coming on.

All I have to do is open the coolant tank cap and let the pressure out. The level then bubbles up again and the car is fine to drive until I next switch the engine off.

I have to do this everytime before I use the car. The coolant doesn't seem to be leaking anywhere it is just going down due to pressure?

What is going on? Please I am desperate for any suggestions.

Cheers JLS

[FLENG2008]

Banging my head against a brick wall with this one!

After long (and now it is colder short drives) and then leaving the car with engine off, the coolant is going down. When I next start the car the "STOP - CHECK COOLANT" is coming on.

All I have to do is open the coolant tank cap and let the pressure out. The level then bubbles up again and the car is fine to drive until I next switch the engine off.

I have to do this everytime before I use the car. The coolant doesn't seem to be leaking anywhere it is just going down due to pressure?

What is going on? Please I am desperate for any suggestions.

Cheers JLS

a pressure test should sort you out, it could be a leaking rad, there pretty common, i think mine leaks very slighlty.. or worse case it could be head gasket?

[Crasher]

This is often due to a faulty coolant tank where the sensor rods are dirty or faulty. We have also had this with a dash fault but change the bottle first; they only cost about £10.

[Col]

If the coolant is gurgling back up to level once you take the cap off it would indicate that you are releasing excessive pressure.

Sadly this is usually caused by head gasket failure.

Is it an AJM engined PD 115hp by any chance ?

[JLSTDI]

Thanks for the replies.

It is indeed gurgling back up after releasing the cap. Drove about 70 miles yesterday and although the "STOP- COOLANT" didn't come on during the drive it came on this morning when I started the car.

Took the cap off as usual, bizzarely there wasn't the normal high pressure this time and the coolant didn't gurgle back up to level. It just stayed low and I had to refill from just below the min level mark to back up to the max mark.

Also, don't know if this is connected but when I start the car I now have to wait about 30secs for the glow light on the dash to go out before I can start it.

There is slime under the oil filler cap but none on the dipstick. I assumed the slime was normal on shorter journeys in this cold weather. Hoping that it is not a Head Gasket prob. How can I check properly? Would a pressure check do it?

And yes it is a PD115hp Engine. Is that bad?!?

Thanks again.

[Crasher]

The AJM engine is slightly prone to head gasket problems.

[Thedeester1]

Im no expert but the coolant tank should allow expansion. As the coolant heats up it expands and should push some air out of the tank. As It cools it contracts and draws the air back in. I dont think the system should be completely sealed (I may be wrong) check the expansion tank for a little pipe that has nothing attached to the other end and check its not blocked. sometimes the tank cap itself has a breather fitted to it. Before paying for head gasgets and strip downs id check the simple stuff.