Hello - 

 

I bought a '97 legacy EJ22 with 125k miles and a new head gasket installed by a mechanic (don't know the details). This was 10k miles ago and far, far away.

 

Recently I started noticing dropping coolant levels. I found a big crack in the block-to-heater hose, flushed coolant (prestone kit) and replaced the hose, refilled with pure water.

 

Now its overheating/low coolant again. It's very possible I hadn't re-bled the system properly. But here's the kicker...

 

There is a distinct gas smell in the coolant and some clumps of white milky sludge. When drained the coolant smells burnt, has a vague oil slick on top, and is tinted yellow (it was clear water). HG, right? BUT, I did a combustion leak test to check for CO2 in the coolant, and it came up negative both times. There is also no bubbling in the coolant overflow tank. 

 

Could this be residue left over from the previous HG failure? Is it possible to get gasoline/oil in the coolant but no exhaust? 

Edited October 30, 201411 yr by ztrain727

I think it's possible to get oil in the coolant but not exhaust if the HG somehow has a breach between the oil and coolant ports.

 

If you added only water after the work it could have picked up a trace of yellow from the liquid remaining in the cooling system (assuming the previous coolant color was green/yellow). If you did add only water, that isn't good, you need coolant or at least something like water water for the corrosion inhibitors for the aluminum in the radiator and engine. Subaru has mentioned in the past using distilled water to make sure it is free of trace minerals.

running plain water is not a good idea - in any car.

 

the color tinge is most likely from residual coolant that was left in the system - the other things you mention could be leftovers from the previous headgasket failure...

 

I would advise you drain the system and refill properly with premixed 50/50 coolant - around $7 a gallon - you will need about 2.5 to do the job correctly.

 

do a search here for how to burp the coolant system properly to avoid air pockets in the system.

Thanks - I understand that the issues with running just water, especially tap water, for an extended period (corrosion, boiling point). The plan was to run it for just a day and then drain it as a flush. 

 

When all these other problems popped up, I didn't want to fill it with coolant (I got phosphate free pentofrost - it's a little pricey) just to drain it again a few days later. 

 

I will go ahead and refill it with a proper 50-50 mix and burp it as you say. Fingers crossed this is all residual. 

Edited October 30, 201411 yr by ztrain727

yes there is generally lots of debris and residual stuff in the cooling system and overflow tank/hose.

 

if it is low coolant - then the goal is to find the leak. 

 

premixed 50/50 coolant - around $7 a gallon -

 

where???

 

 

you will need about 2.5 to do the job correctly.

more like 1.5 gallons, 6 qts.

where???

 

Northcentral Wisconsin - at least thats what it was last time I bought some - about a year ago...

 

more like 1.5 gallons, 6 qts.

 

ok, so I over-estimated...better too much than not enough