Overheating after waterpump change!

[cliffdunedin]

Hey team, i have a overheating problem with my BG5 GT.

I changed the waterpump and thermostat (OEM) as it was leaking. So did the cambelt at the same time, put it all back together and took it for a run.

After about 20mins of running it just started to overheat, very quickly, i got home before it got too hot and had a look, the engine was very hot but the bottom hose was not (slightly warm) instantly i thought the thermostat was poked, so pulled it too bits again and tested the thermostat (hot water trick) but it seemed to open no worries!

I did notice that the right side fan (looking in the bonnet) was not going when it was hot...which i assume would be going by that point!

Can anyone give me an idea what could be up? and also how i can test the fan/fan wiring when its supposed to only kick in when its hot. Thanks heaps!!!

[zarnah]

the fan shouldnt really matter as a lot of people with front mount kits only run one fan, even up to reasonable power levels, have you checked to see if your heater core is blocked? flushed the radiator? headgaskets all good? not pushing water out the overflow?

[Drunkenmonkey]

Turn ac on to see if fans go

[cliffdunedin]

 zarnah']

the fan shouldnt really matter as a lot of people with front mount kits only run one fan, even up to reasonable power levels, have you checked to see if your heater core is blocked? flushed the radiator? headgaskets all good? not pushing water out the overflow?

Sorry, yes pushed water out of the overflow!!

Radiator and head gaskets are all good. Didn't think the heater core would be a prob but will check that out!

[quote name='Drunkenmonkey said:

Turn ac on to see if fans go

Yeah i did, the fans didnt start!

[Guest]

all air locks out?

[cliffdunedin]

 liquid_ice said:

all air locks out?

Fairly sure...though my first time with a BG5, so was not 100% sure how to do it :'(

Tips??

[zarnah]

I always fill the system with the front of the car raised, either on a slope ar jack the front up slightly and that seems to work pretty well

[marc]

yeah or use the little hose on top of the drivers side radiator tank to bleed it... Also id just check heater core flow as suggested with the garden hose or by looping it on the engine side. (2 pipes under the intercooler) then make sure radiator isant blocked. Check the obvious for fans, IE plugs that u most likely would have removed doing the cambelt. possible fuses or relays. That would be my starting points after thermostst test u did lol. another good trick I have learnt is get a 2.25L coke bottle and cut it just up from the base then wrap the neck in insulation tape till it fist snug into the header tank then fill that so that the water level sits about half way up and run the engine. works good for bleeding the cooling system and makes observing for head gasket bubbles etc nice and easy/blatent.

There are proper tester kits that include proper funnel type devices with radiator cap dummy fitting for doing this but thought id share the above way since I doubt you have/tryed one yet on the vehicle yet

[Guest S T E Y E]

yea a cold lower pipe and hot top overheating would indicate air pocket to me...

ive never had trouble bleeding mine and previous wrxs...though i think the key is patience hahaha...dont just think aw yea she be right

[madmike]

 S T E Y E said:

yea a cold lower pipe and hot top overheating would indicate air pocket to me...

ive never had trouble bleeding mine and previous wrxs...though i think the key is patience hahaha...dont just think aw yea she be right

Can also indicate a blown HG....

Don't want to be a downer but mine had exactly the same symptoms with a blown HG....

[Guest S T E Y E]

:( :( :(

[cliffdunedin]

Cheers for the help guys i will give those tips a nudge.

 madmike said:

Can also indicate a blown HG....

Don't want to be a downer but mine had exactly the same symptoms with a blown HG....

I thought the same, but no oil in water or water in oil!

Will get it pressure tested if i have no luck.

[zarnah]

each time i have seen a subaru with a blown hg there has not been oil in water or water in oil, they usualy blow near the combustion chamber and leak into there rather than between the oil and water gallerys

[DRFVDR]

 cliffdunedin']

Cheers for the help guys i will give those tips a nudge.

[quote name='madmike said:

Can also indicate a blown HG....

Don't want to be a downer but mine had exactly the same symptoms with a blown HG....

/quote]

I thought the same, but no oil in water or water in oil!

Will get it pressure tested if i have no luck.

why oh why do people think that if u have a HG gone u get oil in water or vise versa

I have seen many many HG go and have never seen oil in water or water in oil

[cliffdunedin]

 zarnah']

each time i have seen a subaru with a blown hg there has not been oil in water or water in oil, they usualy blow near the combustion chamber and leak into there rather than between the oil and water gallerys

Cheers thanks for that, if the other ideas don't work i will get it pressure tested

[quote name='DRFVDR said:

why oh why do people think that if u have a HG gone u get oil in water or vise versa

I have seen many many HG go and have never seen oil in water or water in oil

Thanks for posting on the interweb and your constructive post ;D

[Guest S T E Y E]

well i havent blowen a subaru up but most cars do put oil in water or water in oil... there is alota ways the headgasket can blow...most comonly is combustion entering the water galleries ie pressurising the water and pushing it out over flow

but like i said the headgasket can give out in different places depending on wats wrong with it...normally compression leaking is from detonation / too much boost... other ways is overheating