Overheating EJ22T

[2.2TLegacy]

Lately this car has been fix one problem and another arises.


Stroker EJ22T build, it has always hated slow, stop and go traffic, would always start to run a little hot but as soon as you started moving consistently (10mph+) it would cool right right down and go back to normal.

Yesterday, same thing happened yet once I started moving again, the temperature continued to climb. Limped it a few miles to where I was going and let it sit for a couple hours. Got into it to go home, pulled on the freeway and watched the temperature just soar to red. Turned it off and pulled over, limped home yet again.

Weird thing was on my drive home, i tried to dissipate some of the heat by turning the heater on full and to my surprise, cool air came out. Then a few seconds later it was piping hot, then back to cool and i think you get the pattern.

I hate, hate, hate cooling systems and always loath working on them so instead of poking in the dark do you guys have any insight on where to start?

[JDMSLIK]

Cheapest process, make sure your fans are turning on, replace thermostat. put about 5-6 litres of coolant or until it won't take anymore. Keep the rad cap off, start up the car and add coolant as it lowers. Once you get up to operating temp rev it manually from under the hood adding coolant as it takes it. Rev it for around 10-15 minutes keeping it around 2500 rpm, this will help get the bubbles out, this gets messy eh.
If the problem persists grab a hold of the lower and upper rad hoses individually. Trying to remember...I believe if both hoses feel like they are the same temp you got a clogged rad. After that I'd look into a head gasket failure.

As spring hits temperatures are rising. I had this last year this time, my fans had a nasty connection and I didn't notice it over the winter. Spring came and I started overheating. Hopefully it's just the fans. But it does sound like you have some sort of bubble or air lock in the system. Does the exhaust smell sweet?

[2.2TLegacy]

Ok here is a weird thing. Threw the check connectors (green) together to see if the rad fan was working, which is was. Yet when the car was running the rad fan never turned on...what would cause this?

[2.2TLegacy]

UPDATE: I don't have the time or space to work on it right now, off to the shop it goes, I'll report back with what they find.

[JDMSLIK]

trying to remember if there's two seperate coolant temp sensors

[kimokalihi]

There is. One for the gauge and one for the ECU.

[kimokalihi]

If you're getting both cool and hot in the heater you have air in the system and it needs to be burped. Park it on a level surface and let it idle with the cap off the fill tank for a good half hour and keep squeezing the radiator hoses. Wear a glove if it gets too hot. Watch the temp gauge. Might want to jack the front end up to try and get air out of your heater core.

[2.2TLegacy]

got the word back today. Needs a new radiator, fan motor, radiator cap and the bypass line that runs under the intake manifold is leaking...oh happy day. Anybody know a good place to get a new rad and fan motor (or assy)?

[Legacy777]

Other thing to check is that there is a stock subaru thermostat.

[kimokalihi]

Why does is need a new radiator? Clogged?

[2.2TLegacy]

Why does is need a new radiator? Clogged?

restricted flow.

[Apex3]

That sounds like bull to me. I can't see all that being bad at once.

[kimokalihi]

Same here. You can't ever trust shops. Just replace the cap with an sti cap from the subaru dealer and the thermostat with a subatu genuine themostat and see if the problem goes away. I still think its air in your system or maybe partially clogged heater core.

[2.2TLegacy]

They are a very reputable independent subaru repair shop so I dont think they are taking me for a sucker. Heater core is fine as it was replaced with a brand new one when i did my build. I had them do a drain and fill and replace the rad cap and everything seems to be fine for now.