Ideas.

[chris wrx]

Does anyone have any idea why my coolant in my expansion bottle bubbles ?
Had new head gaskets recently , brand new radiator cap fitted and it still bubbles even after driving for only 10 mins , starting to get pi**ed of with it now.

[munk]

Will it not bubble slightly with water circulating?? Only a random stab I'n the dark??

[scooby doo]

Whats the temp gauge doing chris?

[Scruff]

I thought bubbles normally indicated a leak? :S

[chris wrx]

Temp gauge stays normal , car drives fine , will blow a bit of coolant out top of expansion bottle under full boost i guess ????

[sumo-scooby]

Its a long shot but have herd this in the past and it was caused by a small crack internaly in the turbo allowing boost air into the coolant system

[scooby doo]

Thats a pressure build up, umm.. id speak to a specilist but in my eyes could be at worst a cracked head? did you have them pressure tested?
any oil in the water or water in the oil?
were exactly are you getting the leak from the bottle down behind the headlight or the rad cap bottle?

[scooby doo]

Originally Posted by sumo-scooby

Its a long shot but have herd this in the past and it was caused by a small crack internaly in the turbo allowing boost air into the coolant system

thats a new one but sounds visable, how would you check tho without sawpping tubbys over?

[chris wrx]

Originally Posted by scooby doo

Thats a pressure build up, umm.. id speak to a specilist but in my eyes could be at worst a cracked head? did you have them pressure tested?
any oil in the water or water in the oil?
were exactly are you getting the leak from the bottle down behind the headlight or the rad cap bottle?

the bottle behind light .

[scooberblue]

does definatly sound like head gasket going again as the colling system is back pressureizing.
were the heads scimmed an was it dony by a garage or specialist?

[chris wrx]

Heads done proper , scimmed and genuine subaru gaskets by a reputable mechanic , hardley done any milage since.

[scooby doo]

Id take it back to the garage that did the work or go see Vince at Rds Up Brunel road in Hastings, he should be able to help. very good with Subarus, I know Scott recommends also.

Some bubbles is normal? or so I thought....

Try putting some block test fluid through it and see if it changes colour, should tell you if you have a HG/problem.

Maybe worth draining coolant and refilling making sure theres no air in the system..... worth replacing thermostat for the cost at the same time.

Check the pipes around cooling system, maybe drawing in air somewhere..... are you only getting bubbles in the overflow tank and not the header tank?

[scooberblue]

haveing 1 bar pressure in the headertank after only 10mins driveing does defo sound like the beggining of headgasket

if you have bubbles in the expansion tank then that means the headertank cap is opening and that is rated to 1bar! you could try a 1.3bar cap but if it is headgasket it will make it fail alot quicker thou.if its headgasket it will slowly push water out the expansion bottle so keep an eye on the headertank water level

id take it back as scoobydoo suggests

[chris wrx]

Originally Posted by thepieman

Some bubbles is normal? or so I thought....

Try putting some block test fluid through it and see if it changes colour, should tell you if you have a HG/problem.

Maybe worth draining coolant and refilling making sure theres no air in the system..... worth replacing thermostat for the cost at the same time.

Check the pipes around cooling system, maybe drawing in air somewhere..... are you only getting bubbles in the overflow tank and not the header tank?

only in the overflow tank.

[chris wrx]

As soon as fans come on bubbles stop , maybe thermostat not working properly and water gets a bit hotter than normal ? temp gauge reads ok.

[asperformance]

or goosed pressure cap..............

[chris wrx]

Brand new rad cap fitted

[scooby doo]

in orignal post chris said the cap is replaced.
Chris cheapest option replace thermostat, while at it do what ron surgested and check all hoses for splits or tightness to make sure you dont have air entering the system, mine had a tiny tiny hole in the heater matrix pipe, then if all good and no luck,

Could be cracked liner, cracked head one of 2, warped block so not sealing great, or just something really really simple, the worst ive mentioned i havnt seen on a scoob myself or heard off so dont panic.it really could be silly, have you got a plastic header tank as these get hairlines crack,

[chris wrx]

will have to get someone to give it the once over mate

[scooby doo]

if stuck run it round and ill do the some standard checks.,

[chris wrx]

ok mate i'll give u a bell