Coolant leak on 2.0 bluehdi - is this serious?

[sneakyfox]

I have a coolant leak on my Boxer and am wondering if it's something I need to take a look at or if it's okay to just top up with coolant when it drops down.

It leaks around 120-150ml per month.

It can't quite get to see exactly where it leaks out but these are the best photos I could get.

The pipe marked with X in both pictures is the same. The second picture is taken from below.

The coolant runs down above the pipe and then runs on to it. I'm not sure the colour is really from rust, but rather from dirt on the outside of the engine.

Appreciate any thoughts!

[mickthemaverick]

There are mixed views on slight coolant leaks. Some say try using a sealant like radweld and others say don't let it near your engine. I would try checking all the hose clips for security and then possibly try a pressure test with the engine off and see if you can spot the weep.

[myglaren]

I certainly wouldn't let Radweld or Barr's Stop Leak anywhere near anything that I owned but Forté Radiator Stop Leak & Cooling System Conditioner is recommended for Citroens and indeed essential for the warranty if fitting a Valeo heater matrix. IIRC I believe that Liquimolly have a similar product.
https://www.forteuk.co.uk/product/radia ... nditioner/

[windy1603]

I would not leave it for long as air can get trapped in the head and cause the head to overheat, boiling the coolant which then vents from the header tank.

You may be lucky and its just the gasket on the thermostat housing if not a new housing will be need. Based on my experience not the easiest to change (the clamp bolt on the solid pipe that goes behind the engine is a pain) and they are very expensive I was quoted over £300 from Peugeot got a quality OEM replacement (had the PSA Logo's ground off) for £145

[sneakyfox]

Thank you for the replies!

I seems like Forte is not a thing here in Spain but there is this Liquid Moly product: https://www.amazon.es/Liqui-Moly-2533-R ... B01DT5TZ8A
It looks like Wynn's has a similar product too.

I don't think I have the tools to do a pressure test, I guess you need a compressor and fittings for that? So it would probably be a trip to the mechanic in that case.

I would not leave it for long as air can get trapped in the head and cause the head to overheat, boiling the coolant which then vents from the header tank.

You may be lucky and its just the gasket on the thermostat housing if not a new housing will be need. Based on my experience not the easiest to change (the clamp bolt on the solid pipe that goes behind the engine is a pain) and they are very expensive I was quoted over £300 from Peugeot got a quality OEM replacement (had the PSA Logo's ground off) for £145

Sounds like it's going to be some work.

For what it's worth, after heating up the needle on the temperature gauge sits right in the middle, never moves at all.

I have never seen any liquid or smudge around the header tank. Even if coolant escapes as steam wouldn't it still leave traces there?

It looks like you can get a new aftermarket thermostat for 110€ in Germany: https://www.autodoc.de/fast/22054447
There are more expensive ones too.

[PaulC5]

The hose clip on the lower photo looks to be missing the screw part that tightens it up if it is a jubilee clip. If so it might just need a clip replacement.

[sneakyfox]

Thanks but I think there is a screw on the opposite side, not visible on the photo. But the coolant is running down from above, probably somewhere on the thermostat housing.