1997 Impreza Coolant Overflow Issue

Heads, valves, pistons, rods, crankshaft, etc...

Moderators: Helpinators, Moderators

Post Reply
Legacy777
Site Admin
Site Admin
Posts: 27884
Joined: Tue Oct 15, 2002 11:37 am
Location: Houston, Tx
Contact:

1997 Impreza Coolant Overflow Issue

Post by Legacy777 »

I've been having an issue for some time now where the coolant gets pushed to the coolant expansion tank as it expands and is not sucked back into the radiator as it cools. I've manually drained the expansion tank back into the radiator and it does the same thing the next time I drive. My engine temps are good.

I've tried testing the radiator cap and it does seem to hold pressure and relieve around where it should be. However, it doesn't really test vacuum. The only other thought I have is a headgasket issue. I need to test the coolant for hydrocarbons....I just haven't gotten around to it. I suppose the easy test would be to replace the radiator cap first.

Any thoughts?
Josh

surrealmirage.com/subaru
1990 Legacy (AWD, 6MT, & EJ22T Swap)
2020 Outback Limted XT

If you need to get a hold of me please email me rather then pm
mike-tracy
Moderator
Moderator
Posts: 5000
Joined: Tue Aug 25, 2009 7:52 am
Location: Des Moines, Wa

Re: 1997 Impreza Coolant Overflow Issue

Post by mike-tracy »

Every Subaru of mine that did that had blown HGs. 2 of those were even Ej22e's. One of which was from my 98 OBS.

If you carry a turkey baster around, like I did in my college days for this exact purpose, you can transfer coolant back into the radiator when it's cold. Now that I have a career I wouldn't think of doing that. The car in question (96 Legacy L) lasted like 40k miles before I replaced the engine with the vastly more reliable ej25d ;p
1992 Legacy SS 5mt, build in progress
Josh Colombo wrote: Mon Jan 14, 2002 10:23 am Wait....I'm confused now.
Legacy777
Site Admin
Site Admin
Posts: 27884
Joined: Tue Oct 15, 2002 11:37 am
Location: Houston, Tx
Contact:

Re: 1997 Impreza Coolant Overflow Issue

Post by Legacy777 »

In the back of my head I kind of figured it would be the head gasket. When I get time or feel like it I’ll do the hydrocarbon sniffer. I’ve got another car to drive besides the Legacy so it’s not urgent....and I may be looking at something else come fall. We’ll see.
Josh

surrealmirage.com/subaru
1990 Legacy (AWD, 6MT, & EJ22T Swap)
2020 Outback Limted XT

If you need to get a hold of me please email me rather then pm
scoobiedoo22
First Gear
Posts: 144
Joined: Wed Oct 16, 2002 9:04 pm
Location: Michigan's Upper Peninsula
Contact:

Re: 1997 Impreza Coolant Overflow Issue

Post by scoobiedoo22 »

Could be a bad/clogged vacuum valve in the radiator cap that's not allowing the coolant to be drawn back into the coolant system. There are a few ways to check for excessive vacuum as the engine cools down, the easiest being doing a visual on the upper radiator hose and seeing if it appears crushed from the vacuum once cooled. Another cheap way is after the engine has cooled is to release the radiator cap and see if there is a pop or some auditory indication there is a pressure difference between the radiator and the outside atmosphere. Might be a cheap fix to check and then pick up a replacement cap to see if the issue goes away. Either that or just do a mike-tracy and swap over to the 25d since we all know they never have head gasket issues!
1991 Legacy SS 5-Speed

1999 Impreza 2.5RS Coupe
Legacy777
Site Admin
Site Admin
Posts: 27884
Joined: Tue Oct 15, 2002 11:37 am
Location: Houston, Tx
Contact:

Re: 1997 Impreza Coolant Overflow Issue

Post by Legacy777 »

So I did a hydrocarbon/CO2 detector test on the cooling system yesterday and it came back good. The fluid stayed blue. I verified the fluid was still working properly. So I'm going to try a new radiator cap and see if that fixes the issue.
Josh

surrealmirage.com/subaru
1990 Legacy (AWD, 6MT, & EJ22T Swap)
2020 Outback Limted XT

If you need to get a hold of me please email me rather then pm
DuceDuceTurbo
In Neutral
Posts: 2
Joined: Tue Aug 24, 2021 1:31 am

Re: 1997 Impreza Coolant Overflow Issue

Post by DuceDuceTurbo »

Did you ever find a fix for this problem. I have the same issue on my 94. Never overheats but pushes coolant.
arse_sidewards
First Gear
Posts: 98
Joined: Thu Jul 21, 2016 12:17 pm

Re: 1997 Impreza Coolant Overflow Issue

Post by arse_sidewards »

DuceDuceTurbo wrote: Wed Sep 08, 2021 2:46 am Did you ever find a fix for this problem. I have the same issue on my 94. Never overheats but pushes coolant.
Replace the hose going into the coolant bottle. Check for hydrocarbons in the coolant if that doesn't work.
'93, '93 and '94 Legacy L, wagons, FWD and AWD, all are NA 2.2 w/ 4EAT.
Legacy777
Site Admin
Site Admin
Posts: 27884
Joined: Tue Oct 15, 2002 11:37 am
Location: Houston, Tx
Contact:

Re: 1997 Impreza Coolant Overflow Issue

Post by Legacy777 »

DuceDuceTurbo wrote: Wed Sep 08, 2021 2:46 am Did you ever find a fix for this problem. I have the same issue on my 94. Never overheats but pushes coolant.
Unfortunately I never did. I checked for hydrocarbons in the coolant and didn't find any. I sold the car to a friend and he drove it and didn't have issues. So either the coolant level dropped and is still working ok or it stopped (which probably unlikely).
Josh

surrealmirage.com/subaru
1990 Legacy (AWD, 6MT, & EJ22T Swap)
2020 Outback Limted XT

If you need to get a hold of me please email me rather then pm
DuceDuceTurbo
In Neutral
Posts: 2
Joined: Tue Aug 24, 2021 1:31 am

Re: 1997 Impreza Coolant Overflow Issue

Post by DuceDuceTurbo »

Thanks for your reply. Mine is very strange as the last time I rallycrossed it she didn’t push any coolant all day then the 1 hour drive home and the coolant was almost out of the overflow. I guess I’ll keep checking. Thanks again
Legacy777
Site Admin
Site Admin
Posts: 27884
Joined: Tue Oct 15, 2002 11:37 am
Location: Houston, Tx
Contact:

Re: 1997 Impreza Coolant Overflow Issue

Post by Legacy777 »

Yeah, mine was similar. I couldn’t really figure out what the issue was. I assume it’s probably head gasket related but was unable to definitively prove it.

If you’re able to figure out the cause and any additional details please update this post.

Thanks
Josh

surrealmirage.com/subaru
1990 Legacy (AWD, 6MT, & EJ22T Swap)
2020 Outback Limted XT

If you need to get a hold of me please email me rather then pm
Mister Anderson
First Gear
Posts: 214
Joined: Sun Aug 28, 2011 7:20 pm
Location: Vancouver, WA/ Spokane, WA

Re: 1997 Impreza Coolant Overflow Issue

Post by Mister Anderson »

My 2009 Toyota was doing the same thing. Pushing coolant and not sucking it back in. It turned out to be a blown head gasket.
91 black SS 5 speed (Canadian).... Closed deck EJ20G, fully built, V5/6 sti ra drivetrain, haltech stand-alone
93 silver TW 5 speed... rebuilt 22T with 20G heads, wrx ra drivetrain, otherwise stock.
73 kazen red VW bus riviera camper
Post Reply