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1997 Forester turbo filling overflow - not overheating

matdaymon

Forum Member
Joined
May 16, 2015
Messages
86
Location
New Zealand
Car Year
NA
Car Model
1997 SF5A Forester T/TB
Transmission
4EAT
Hey all, have a weird issue with my foz that I'm hoping you'll be able to help me with.

Engine is an EJ20G before we get started and the cooling system was chock full of rust when I bought the car (replaced all the hoses and flushed it thoroughly with citric acid).

The car has started to fill the coolant overflow bottle after driving, but the car isn't overheating.

Other symptoms are the top main radiator hose is compressing in on itself too after this has happened/when the car has cooled down, and when I undo the radiator cap it returns to its normal diameter.

Is this an issue with the radiator/radiator cap cap or is my thermostat ****ed?
 
sounds like your radiator cap is letting overflow out at too low a pressure, then not letting it back in when it cools down and a vac. is produced.

Cheap to replace and find out.
 
Thanks guys will swap on a new radiator cap from Repco and see how it goes.
 
Gidday Mat

Also check the radiator to header tank outlet hose and clamp at the radiator neck. Mine was leaking slightly after Ross replaced the radiator. NachaLuva noticed it one day when I was at his place, and put a new SS clamp around it :ebiggrin:.

Also worth checking that the header tank tube ends are tight, both inside and outside where they plug onto the header tank cap.

If any of these can leak air, the coolant return system will not work.

However, given that there is vacuum created in the cooling system, I still agree with Duncan that the radiator cap is probably past its use-by date. Worth checking the others, as they might also be a problem.
 
Use a genuine cap not cheap stuff.

Also flush out your heater core with a garden hose, from both directions
it sits fully inline with the coolant flow, if it's blocked you get no flow and it cooks itself.
 
Thanks R,
Heater core was thoroughly flushed when I replaced the hoses. Actually flowed better than my BF7s did and that car had a less clogged system.

Will aim for a genuine cap when funds allow. Need to stop by the dealer at some point for some upper engine cleaner anyway. For now it appears to be doing ok. Next trip out fishing should show whether the repco cap is doing its job.
 
No sounds of waterfalls, etc form the dash
indicating an airlock in the system

they're a tempremental cooling system if not bled properly
 
Still chasing away the waterfall in mine, and that doesn't have the turbo complications.
 
Well changing the radiator cap and tightening up the clamps on the overflow hose seems to have done the trick. It's still filling it up but is managing to suck whatever it pushes out into it back into the system when it cools down.

Not sure whether or not my first SF5 did this which has me slightly curious / worried but so long as nothing else comes of it I guess I'll leave it alone for now.
 
Good outcome, Mat :).

That is the perfectly normal behaviour, and how it's supposed to work.
 
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