Coolant on top of thermostat

[alastairb]

What's going on here then ? Came out to a puddle under the car, yesterday was the first warmish weather in a while.
Bit of coolant sitting on top of what I assume is thermostat (or water pump?)
Is this common ?
Cheers

 

[midlifecrisis]

Coolant bottles are prone to cracking , i believe due to the plastic becoming brittle. Check for any dampness around that.

 

[Zep]

Can’t see any wetness above so without wishing to state the obvious, either the hose to the thermostat or the o-ring under it are leaking.

If you are changing the o-ring, do the stat as well as they are know to get a bit flakey with age.

 

[allandwf]

What's the green stain on the small pipe above it, centre of the pic? Possibly dripping down from there?

 

[Zep]

What's the green stain on the small pipe above it, centre of the pic? Possibly dripping down from there?

Looks like paint pen to me, they mark all the connections for tightness from the factory.

 

[alastairb]

Yeah it's pretty dry around it.
If the O rings have happened before that makes sense.

Cheers all

 

[allandwf]

Looks like paint pen to me, they mark all the connections for tightness from the factory.

I thought they used yellow back then?

 

[Zep]

I thought they used yellow back then?

Are we talking about the same bit?

 

[alastairb]

I've a mix of yellow and pink check pen marks.

Just been out again to have a look, coolant pooling in a small recess next to the thermostat, dripping down the front of the block, under tray carpet saturated etc.

The pipe to the thermostat has some coolant crystals and doesn't look too well seated so I'll probably replace that.

Thanks again !

 

[conaero]

It’s usually the thermostat housing O ring.

Take the air filter box out completely to do it and a smear of sealer is advisable.

 

[allandwf]

Are we talking about the same bit?

View attachment 125482

No I was talking about further down and to the right. But hopefully it will be sorted.

 

[philw696]

The Best way to test the cooling system is to pressure test it and see if it drops and where the leak is.
Any Good workshop should be able to do this for you.

 

[TimR]

I added a UV dye to the coolant when I wanted to find the source of a leak. With the right light, you can hopefully find the cause. In my case, the engine front cover to water/oil pump o-ring failed. Let’s hope you have an easier fix than that…
Bit of a bar-steward flushing the dye ever since too….