I am an Activaist-v6 and a 2.1Estateerr

[elma]

This is fabric (No4) ?

I'm reasonably certain pipe 5 is metal braid on my cars, will have to check when home.

The more I think about the water absorbance theory the less I believe it.

[Stickyfinger]

New header tank all fitted, RED OAT used and all ports vented of bubbles.

?? Is the little Matrix vent cap the same as a tyre valve cap ?? as mine is in the engine down in a dark place !

Will this happen ?

[CitroJim]

It's a bodge... Better to have an ally one made. It will then last a lifetime.

[Stickyfinger]

Same thread ??....I have some metal ones

[elma]

Is the little Matrix vent cap the same as a tyre valve cap?

No, they have an o ring. Tyre valve caps are hit and miss weather they leak or not.
Xantia spare wheels are fitted with the right one, if you have an original spare check it. The caps shorter, rounder and has an o ring inside.

[Stickyfinger]

Will do....thanks James

I have some metal caps, the type with a valve screwdriver on top....will look at those as well

[Stickyfinger]

That is done then......thanks for the info.

Aggg,,,,its HOT down there, red arms

[chinkostu]

the cap needs that little o ring. i replaced mine with a cheap one and it split spewing coolant everywhere!

[Stickyfinger]

It has one inside.... is that not what you meant ?

Standard caps on spares BTW....would PTFA wrap on the threads do the job ?

[elma]

If it has an o ring it should be fine.
Citroen and Peugeot sell them for small change anyway.

[chinkostu]

It has one inside.... is that not what you meant ?

Standard caps on spares BTW....would PTFA wrap on the threads do the job ?

If its got the o ring and it's metal it's probably better, as long as the cap doesn't sieze on (dissimilar metals!)

[Stickyfinger]

Then maybe I will put a little liquid ptfe on the thread then....I have it for use on the radiators anyway

[myglaren]

Citroen changed from plastic to metal a few years ago.
I had a plastic one blow off during the MOT and fill the pit where the tester was working with boiling water. He wasn't impressed.
I suspect it wasn't the proper one but a valve cap that had been substituted.
Passed the MOT anyway.

[Stickyfinger]

LOL....based on that I WILL leave the metal one on then

[Stickyfinger]

Oh good....all OK, no leaks, water holds level, hold temp....so jobs a good'un

BUT

Wine/howl from the left side of the engine.....sounds like a belt tensioner.....but worryingly it does not seem to sound like a aux belt to me (but I hope my inexperience is making me worry to much)

Speed related as it increases in intensity, goes over 2k. Was thinking it was coming from the rear cam at first.