Header Tank Hiss

[mgbond]

Hi Guys,

After a blat and then a little town driving I pulled over let the fans kick in and off. I then switched off engine and lifted rear Clam, I noticed a slight hissing coming from the cap of the header tank and the very top of the water level moving a bit.

Not been loosing any water, wondered if I have a air block or the cap isn't letting the water pressurise enough?

Any Ideas?

Bondy

[daddysumo]

yep air in the system, takes me ages to bleed mine all out,also the return from the turbos is very hot and returns almost directly to the header tank.

[mgbond]

daddysumo said:

yep air in the system, takes me ages to bleed mine all out,also the return from the turbos is very hot and returns almost directly to the header tank.

I think it might also have something to do with my heater always being on cold. Will do the run it up without cap on and heater fully on to see if that does anything?

Bondy

[daddysumo]

Check the main rad is getting hot all over,not just warm,mine didn't untill I blead it manually, the fans help to let you know if they are on more than usual and for longer... then you most likely have an air lock.
Your ECU gives you real water temps so check what they are with the car idling.

[Blu3R]

mgbond said:

Will do the run it up without cap on and heater fully on to see if that does anything?

Bondy

Not wanting to teach you how to suck eggs or anything but when you do that, have the cap screwed on at least half a turn. That way when the fans kick in and the level suddenly starts to rise quickly, you don't panic, burn your hand and cross thread the cap

[mgbond]

Let the car warm up with the cap off the header. the temps around the engine got to about 70 and the rad pipes were still cold. After a while the water in the header tank was up to +50 and steam was coming out with little bubbles as i looked inside (rad was still cold). So I assume the heat in the header is coming from the turbo hoses. Any ideas why the bubbles?

I put the cap back on and after a while the rad warmed up all the way through.

Drove to GF's giving it beans (including a high speed run) pulled up left the fans kick in. Measured the temps and around 70 into the rad and not much more at the pipes around the engine, so like normal.

Its the bubbles thats puzzling me.

Bondy

[daddysumo]

I think it's the water boiling in the turbos !

[mgbond]

Still not sure what's going on with this? All temps seem to be fine and car driving well. When the car is reved I get a few bubbles in the header.

I fear headgasket?

Bondy

[mgbond]

Done a bit of reading and it's possible that it's normal to get bubbles from turbos into header. Maybe my cap has failed making it more obvious?

Going to get a new one. The STD one is rated to 120kpa. Should I go up to the next one?

Bondy

[TuxMan]

I get some bubbles too and have done for some time so I guess it's normal ;-)

[mgbond]

Si, you mentioned that some of you guys put a higher pressure cap on. Ford tell me there are no higher ones than I already have (120kpa).

What ones do you have, have you a part number?

Cheers

Bondy

[daddysumo]

We have the pro alloy header tanks....

[mgbond]

daddysumo said:

We have the pro alloy header tanks....

What pressure does it release at?

Bondy

[daddysumo]

around 20 ish psi I think

[mgbond]

Wow that's over double. Why would u need to do that?

[daddysumo]

dunno just need to, the standard pressure cap supplied was not enough and the coolant leaked out of the overflow

[mgbond]

daddysumo said:

dunno just need to, the standard pressure cap supplied was not enough and the coolant leaked out of the overflow

I'm getting this also, could it be the extra power and boost I'm now running. When cold the level is right at the bottom (just inside he filler neck) then when fully hot and after spirited driving it over max?

Bondy

[daddysumo]

I don't think its that tbh..... but hey....

[Fixanything]

daddysumo said:

I think it's the water boiling in the turbos !

+1

[mgbond]

It does it from cold also so there wouldn't be any heat in them at this point?