Coolant header tank

[Paradroid]

On the lip around the top half of the coolant header tank I keep getting a trace of coolant. Is this the cap that's in need of replacing?

It couldn't be an airlock causing it could it? I don't get a lot of heat through the vents (engine warms up fine though), and thought this was the heater matrixes, so unrelated, but thought I'd mention it just in case.

[kaiser]

Yes, your cap is letting out water. It could be tired, they do tire. You may have overfilled, only fill to the max mark on the side of the box, that's about half an inch above the floor of the expansion box.
You may well have air in the system, so run with the heater on, and top up a couple of times.

The engine may well leak, water pump and thermostat housings are prone to leaks.

Oh, I forgot to mention, since you seem new, don't rely on the temperature gauge, and check the water level every day before you drive.

[Paradroid]

It's just had the water pump and thermostat replaced as part of a big service. So I'm hoping there is no actual leaks. It is starting to sound more and more like an air lock,I will check for that first.

Do I just use the screw on the pipe right near the header tank to bleed it?

[Paradroid]

New cap ordered, coming Monday. I hope this is the right move though. The alternative would seem to be head gasket failure. There's no Mayo in the oil but I'm still worried.

Drove the car today after topping up, looked again tonight and spots of coolant all over the airbox so the cap has definitely failed. You can see the rubber seal is split and incomplete

fingers crossed for Monday. Otherwise I'll be gutted

[tazman3]

Originally Posted by Paradroid

New cap ordered, coming Monday. I hope this is the right move though. The alternative would seem to be head gasket failure. There's no Mayo in the oil but I'm still worried.

Drove the car today after topping up, looked again tonight and spots of coolant all over the airbox so the cap has definitely failed. You can see the rubber seal is split and incomplete

fingers crossed for Monday. Otherwise I'll be gutted

would be very surprised if it is HGF not common at all on these engines mate...

Martin

[Dave Goody]

Are you really, really sure you are not overfilling it??

[The Jugs]

I've had this problem twice now. I'm thinking that due to the regular checking, twice a week at least, this serverely reduces the life span of the rubber seal on the cap. Also causing extra stress on the tank neck.

[Paradroid]

Originally Posted by Dave Goody

Are you really, really sure you are not overfilling it??

THink so, I've only topped it up once, and that was because the header tank was empty!

[kaiser]

Originally Posted by The Jugs

I've had this problem twice now. I'm thinking that due to the regular checking, twice a week at least, this serverely reduces the life span of the rubber seal on the cap. Also causing extra stress on the tank neck.

Good! The mantra from the last depression in America was something like:

"Use it up, wear it out, make it do or do without"

and it seems you are indeed doing that. But just for the book, you can replace the O-ring and you can also give it a smear of silicone, that will make it slide gently into place when you screw it on again. Repeat the application once every week.
Rather an O-ring from time too time than the engine even once!
I check daily, and my cap lasts!

[kaiser]

Originally Posted by Paradroid

THink so, I've only topped it up once, and that was because the header tank was empty!

Top it up again, it might require a couple of repeats!
See how it goes once the cap has been replaced, and let us know, please.