Need some help on trying to figger out why this is

I noticed this last week so i went to Central subaru, cauld be a blocked pipe. All seems to be ok tho.

When you take the header cap off it goes back to its normal shape, water level is fine and theres water all the way round the matrix. Runing temp is fine and heaters are hot.

any body now what this could be?

 

More than likely it is the Header cap. Change it you should be fine.

 

Nackered cap ??

 

Is the expansion tank also filling up?
Does the top hose have a sleeve on it?

 

Couldnt posibly be the cap its not that old brought ay brand new one not so long back.

It doesnt have a sleeve on the hose, forgive me for sounding dum what do you meen by expansion tank fillig up? cheers

 

In the corner the little white one.

 

No thats not filling up. We all now what that meens if it does!

HD were done back in jan the start of the year, like i said water level appears to be fine.

I also check engine fluids every week with out fail and its never needed water toping up.

It doesnt seem like HD failer because when thay went last time i was toping up water every day, and that expansion tank was over filling guite bad.

 

Can you blow through the hose that goes from the header cap to the expansion tank?

 

+1

If you still have the old header tank cap I'd try that again. New could be faulty. Especially if its non-genuine or a nasty Chinese knock-off.

Not sure if the actual cap differs in design between models years. The actual header tank has about three variations depending on model year. In theory the caps should be interchangble, but I've never really looked closely enough to compare them.