cooling issues..., fine when driving, spikes when stopped. Options

[malaga_red75]

subaru JDM EJ25 DOHC

So, got my conversion finally road worthy and have noticed that while I am driving around, the car stays at around 200 F. when i stop, or let it idle in my garage... the temp slowly climbs and doesnt stop (i shut it off around 230 F). I am assuming this is an issue with my fans.

I am running a front mounted radiator, using 2 push-style fans. A few things that i think may be wrong...

-There is no shroud around the fans... just the shroud that seals the radiator to the front (since they are push fans, they are mounted on the front side of the radiator, in between the radiator and the nose of the car)

- there is about a 1 1/2" gap between the fans and the radiator (this was just the way that ended up working for mounting the fans)

anyways, i am pretty sure that the cooling system is working (no kinked lines, thermostat working, fans do turn on) as indicated by driving and the temp staying cool, there is just something not working when i stop moving. let me know what you guys think.

-Peter

[charliew]

You must not be moving enough coolant if you need to idle the motor up. I tried the stock 02 wrx radiator in my 914 and it will not fit standing up inbetween the headlight boxes, course it's not a crossflow, it needs to be layed in at a angle that uses much more space. you are not making wrx power though so what you have may work. Are you sure the fans are turning the right direction? I think I read where the exhaust openings need to be 30% bigger than the inlet of the radiator. You can google it. If you use several 90 degree bends in the coolant lines you will get more restriction in the system and you will need bigger diameter lines to overcome the flow restriction. There is is a chance the thermostat is not seeing the bypass flow subys require to send the hot coolant to the thermostat to make it operate right. The stock suby has a heater, a oil warmer/cooler, and the reservoir bolted on the intake the third bypass to the thermostat thats what makes it open and close properly.

When it's idling open the hood and see if it cools ok.

I'm not sure how well you know subys but they do blow headgaskets pretty easy if they get hot very often.

[malaga_red75]

You must not be moving enough coolant if you need to idle the motor up. I tried the stock 02 wrx radiator in my 914 and it will not fit standing up inbetween the headlight boxes, course it's not a crossflow, it needs to be layed in at a angle that uses much more space. you are not making wrx power though so what you have may work. Are you sure the fans are turning the right direction? I think I read where the exhaust openings need to be 30% bigger than the inlet of the radiator. You can google it. If you use several 90 degree bends in the coolant lines you will get more restriction in the system and you will need bigger diameter lines to overcome the flow restriction. There is is a chance the thermostat is not seeing the bypass flow subys require to send the hot coolant to the thermostat to make it operate right. The stock suby has a heater, a oil warmer/cooler, and the reservoir bolted on the intake the third bypass to the thermostat thats what makes it open and close properly.

When it's idling open the hood and see if it cools ok.

I'm not sure how well you know subys but they do blow headgaskets pretty easy if they get hot very often.

I am running a 1996 era 2.5l N/A so, i was comparing my radiator size to that of a 1996-1998 legacy.

Yes, the fans are turning the correct direction. when the turn on, i can feel the air being pulled into the front trunk.

I do know about the headgasket issues, especially with the series motor. I actually do think this might be a possiblity because after driving it one day, i came back, let it sit for an hour, went and fired it up, and a big plume of white smoke came out the exhaust. Will a bad headgasket cause it to overheat at idle, and not while moving?

-Peter

(p.s. Mike (kg6dxn) stopped by yesterday in his sweet 914 -8 and we talked about cooling systems, we talked about different ways of getting the air out of the system, and finding a good high point to pull a vacuum from. Thanks Mike!!)

[ArtechnikA]

Will a bad headgasket cause it to overheat at idle, and not while moving?

In my case, it'd idle all day just fine and overheat within 10 minutes on the road.
I'm not saying your scenario isn't possible, 'cause I donno - but I did have the Subie bad head gasket issue. Idle fine, overheat on the road...