spleenmachine

my 94 wrx has started to blow coolant out of the pipe on the expansion bottle next to the battery after a drive.

the coolant levels always look fine as the header tank is full and the expansion bottle is at the F" mark, i can fill that bottle to the top with coolant and watch it slowly drain away down to the bottom of the bottle it doesnt leak anywhere but i can fill it over and over and it doesnt ever stay full to the brim just keeps disappearing as im watching it.

there is also orange residue around the expansion bottle and when the engines running and i rev it up the water in the bottle goes down then off the throttle it rises again.

coolant doesnt spill out of the pipe on the lid when standing only when i drive the car and when that bottle is full after a drive and i check it the coolant in it is cold although the header tank is hot.

all the radiator pipes get hot and my heating is fine. I only get a fine mist from the exhaust when started from cold in the morning but it goes away and its not enough to worry about.

im not loosing oil and the oil looks fine and doesnt look like its mixing with water.

when i check the coolant in the header tank and rev the car theres frothy bubbles but when i stop revving they go away.

CAN ANYONE HELP AS TO WHAT THIS COULD BE?

Sorry for the long winded rant but i thought i'd be as descriptive as i can as i never seem to get many replys to other posts..maybe i should pretend im a LAYDEE!! as they seem to get a better response thanks for any replys guys!

911

This could be several things.

You ALMOST describe the symptoms of a head gasket failure.
To check for this you can do 2 things.
1
Take the car to a good garage and have them check if there is any exaust gases in the coolant. Theere is a 'tool' to do this. If so, then one of the heads is leaking. Imprezas usually put gases into the water not water into the oil.
2
Fill the system using the tube by the battery.
Get the car warm and blast it for a mile or so. Stop with the engine running and look hard at the water in the tube. are there ANY bubbles emminating from the base? I mean large bubbles.
If so then the head gasket(s) are gone.

Another source of leaking is a split rad end cap on the Header tank side.
This again shows when the system is under pressure, so check there after the hard run.

Another source of leakage is right under the header tank itself, especially if the tank is the plastic type. Theere is a large pipe right underneath off its base. Impossible to see, but the surrounding area will be wet.

Last one i know of is the water pipes to the turbo, but you will need to get well under the car first to chech them. They are well hidden just to annoy you (and the rest of us)

If it is a head gasket, the bill is quite large and there are 2 of them of course.
I do not know where you are from, but the expert in my opinion is David at Welcome to the API website close to Leamington spa, Warwickshire.

API have doe 1100 engines since they opened their doors 8 years or more ago. They understand Impreza engines. Could be worth talking to David there.

Hope this helps you a bit in the search.

Graham.

spleenmachine

THANK YOU SIR...finally a decent answer on here from a man willing to take a little time 2 share the knowledge

i live in sunderland and im closer to AS performance so i'll probs take it there.

also the engine never over heats and when its at optimum temp the water that blows thru 2 the expansion bottle is cold but the water in the header tank is hot and all pipes are hot and pressurised.

911

Alyn is a top guy, had a few dealings with him.
If the heads have gone badly (as one of mine had) the coolant will spew all down the passenger''s side of the car during a good hard full boost blast!

The heater will go cold and the temp will soar too.

You could be lucky!
If you go there send him my best regards, from '911' (then he will charge you more! )

Graham.