Damn cooling system!

[94WRX]

:mad: :mad: :mad:
Stopping at work yesterday i noticed smoke coming from the bonnet scoop. Being on my 3rd radiator i thought i'd soon be on my 4th, but judging by the thermostat housing its not the rad. There appeared to be boiling hot dried coolant all over the thermostat housing, i checked the pipework and its all connected fine. So i squeezed each pipe to check there wasn't a blockage to the overflow, but each time the coolant level in the over-flow bottle went up so there doesn't seem to be any blockages. The thermostat (which i believe is the spring-loaded filler cap) is new so i can't see its not opening properly.

Any idea's what could be causing this to happen? The car's warmed up before each drive....

[wrxfox]

the thermostat is on the water pump and connects to the bottom rad hose
http://i2.photobucket.com/albums/y35/wrxfox/subaruwrxengine009.jpg its the bit in the bottom right hand corner of the picture,i replaced mine recently for a zerosports one that opens at a lower temperature.
rob

[94WRX]

Ah so i'm getting confused, still doesn't really explain why if its overheating why its not making its way into the overflow before its leaking.

[Dyney]

With the engine running does the bottom hose get hot and are the hoses hard?

[94WRX]

I'll check the bottom hose today, but the hoses stay soft. In traffic yesterday there was a small amount of smoke from the scoop again, and i noticed the fan's didn't kick in at all. If its hot enough to overflow, its got to be hot enough for the thermostat to start up the fan's, i think i need a new thermostat.
How much did the zerosports one cost you wrxfox? Is it a straight enough swap?

[wrxfox]

How much did the zerosports one cost you wrxfox? Is it a straight enough swap?
got mine from here very easy to fit straight swap
http://www.dhcars.co.uk/ZeroSports_Impreza_cooling.htm
rob.

[Dyney]

Soft hoses are good :) If they were hard then it would be the head gasket leaking and pressurising the coolant system :o

The thermostat doesn't control the fans, it just lets the water into the rad when a certain temp is reached.

Does it get over hot on the gauge?
Can you se where the water is coming out and causing the "smoke"?


Might just be the ternostat gasket is perished and is leaking from the housing (just above the headers).

[94WRX]

The "Smoke" only comes when its hot, but when i say hot it never goes above the mid-way point on the temp gauge. If the fan's aren't controlled by the thermostat what tells them when to cut in? Would that be linked to the temp gauge as i'm getting concerned why exactly the fan's aren't working.

The only real place you can see the "smoke" coming from is from the exhaust below the filler box is, which houses the filler cap obviously coolant dripping down and the exhaust being very hot is burning it. At no point though has my coolant level really dropped, so its obviously only a small amount.

[Rusky]

Mine sprang a small leak on the header tank,when was stationary no smoke but when i came to a stop after a drive it would smoke the coolant was getting near the turbo and burning,changed the header tank and put new clips on the hoses sorted it.

[Dyney]

Are you sure it's a water leak?

Power stearing resovoirs are a known leak point.

[94WRX]

It could possibly be but the dried fluid on the header tank suggests to me its coolant and the smoke is coming from the exhaust directly beneath the header tank.

[Dyney]

You said the header tank cap was new (BTW this is not the thermosat).
Is it sealing properly? Is there any debris in the neck that might not allow it to seal.
If it was that you should see it leaking when the car is hot.

Do you still have the black plastic header tank?
If so they are Crap!!!! They crack regularly (known problem)
You can make the later metal one fit if you make up a little bracket :)

[ScoobyDuck]

rocker box leak ..thats where smoke rises.

smell it.. is it oil or water?

[Dyney]

Yep, too many things leak there to be able to tell with out seeing it :(