Subaru EJ25 engine forester overheating after timing belt change

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Thank you for your reply.

with funnel full with excess coolant/water, i tried burping the system with engine on till reaching normal temp for about 10minutes.
Should I try burping even longer period of time?
You might need to rev the engine while bleeding the air.
 

dalai

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Temperature on gauge stabilized, and at least 10 minutes with no bubbling/geysers. Then I stick the cap on and watch the gauge for a little longer, then go for a drive.
no geysers when revving high. roger that.

will try tonight and report back sir.
Thanks.
 
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no geysers when revving high. roger that.

will try tonight and report back sir.
Thanks.
If your temperature doesn’t stabilize (fans should be kicking on as well), there’s likely an issue with your thermostat. I forgot- what brand did you use? Does it have the little purge valve in it? Did the little bb in it jiggle before you installed it?

I’m definitely on the anal side when it comes to Subaru engine parts, but I’m a firm believer in buying only the “improved” OEM parts when it’s been a problem that Subaru made a running change to fix something. “Six Star” brand is also the OEM equivalent- “Barn Find Bernie” on eBay carries a multitude of OEM/Six Star parts at reasonable prices.
 

dalai

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If your temperature doesn’t stabilize (fans should be kicking on as well), there’s likely an issue with your thermostat. I forgot- what brand did you use? Does it have the little purge valve in it? Did the little bb in it jiggle before you installed it?

I’m definitely on the anal side when it comes to Subaru engine parts, but I’m a firm believer in buying only the “improved” OEM parts when it’s been a problem that Subaru made a running change to fix something. “Six Star” brand is also the OEM equivalent- “Barn Find Bernie” on eBay carries a multitude of OEM/Six Star parts at reasonable prices.
during bleeding procedure, temperature is always stable for my case. fans kicking in. brand is GMB and NTS, I am japan and bought from store as a set made in japan. they made sure parts were OEM equivalent or from OEM makers.

This time i will replace with fresh coolant just to be sure.
 

dalai

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If your temperature doesn’t stabilize (fans should be kicking on as well), there’s likely an issue with your thermostat. I forgot- what brand did you use? Does it have the little purge valve in it? Did the little bb in it jiggle before you installed it?

I’m definitely on the anal side when it comes to Subaru engine parts, but I’m a firm believer in buying only the “improved” OEM parts when it’s been a problem that Subaru made a running change to fix something. “Six Star” brand is also the OEM equivalent- “Barn Find Bernie” on eBay carries a multitude of OEM/Six Star parts at reasonable prices.
Hi, It happens that Funnel is out of stock so i decided to go to nearest pit shop to do air bleeding by them. They did for an hour with their funnel kit. But still warming up.

I went back to them, they revved till like 3k rpm. it was geysering again and they think something is blocking the way and said might be Head Gasket. But there is no small bubbles coming after geyser.

They are not Subaru pros. Just small town pit shop doing mostly oil change etc. So I am not trusting them like 100%. What do you think?

head gasket etc was completely fine before i changed my timing belt set. Could the HG blow while i change the timing belt, i didnt even turn on engine much. Just cranked twice to loosen crank pulley bolt.
 

dalai

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If your temperature doesn’t stabilize (fans should be kicking on as well), there’s likely an issue with your thermostat. I forgot- what brand did you use? Does it have the little purge valve in it? Did the little bb in it jiggle before you installed it?

I’m definitely on the anal side when it comes to Subaru engine parts, but I’m a firm believer in buying only the “improved” OEM parts when it’s been a problem that Subaru made a running change to fix something. “Six Star” brand is also the OEM equivalent- “Barn Find Bernie” on eBay carries a multitude of OEM/Six Star parts at reasonable prices.
"Update"

Bled the system but fan is not turning off at all, mechanic suggests HG is okay, but thermostat is broken so that it keep signalling engine is still hot even though its idling thus not turning off the fan at all. Sounds legit?

Thermostat is OEM and replaced a month ago,
maybe I installed thermostat backwards? is it even possible to install thermostat wrong way_ ?
 

dalai

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Is the temp gauge hot or is the fan running at all engine temps?
Fan kicks in only after engine reaches midway.
Temp gauge reaches 1 line before red zone (i turn heater on, stop in order not to enter red zone) after going like 20 minutes. Seems i can keep going at this hot temp with heater maxxed on.
I touched upper and lower hose. Upper was really hot but lower was mild. In normal case temp of both hoses close?
 
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Heater is working well, AC as well.

other thing is I reused the coolant and since i spilled some, i added water so its not 50/50, i think now its water 60/40 coolant. Would concentration cause overheating?

when going 50km/h heater turned on, it doesnt overheat, when i turn off heater it tends to heat up.
I don't think the coolant concentration is the problem. Pure water transfers heat better than glycol (antifreeze). Too high a ratio of antifreeze can cause overheating. Your mixtures of 50:50 and 60:40 should both be fine.
 

dalai

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Update*

I, the big moron placed thermostat backwards!
Never have i ever been this happy when i found out i did smth stupid. Now its not overheating.

Thanks guys!! U guys helped me a lot!!!
I was thinking about throwing the car away lol. ☺️
 

dalai

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Is the temp gauge hot or is the fan running at all engine temps?
Hi all,

Another issue due to the overheating came up. It s my AT5 transmission making hissing(kind of air leaking through with high pressure) when gears changed automatically either up or down for like 1 or 2 seconds. Dealer said they will only replace whole transmission whic would be way too expensive.

Do you think its okay? I am driving with the sound for 500mile already, if it would someday completely fail, what would happen? do i just lose the power from engine? or does it get stuck and stop tires suddenly throwing my off the road ? how dangerous could it be if i drive this car to its end?
 
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York, Pa
how do you know when u completed the work?
when revving to 2500rpm, does the coolant geyser up ?
should i keep repeating until there is no geyser when revving up and idling.
yesterday there was no bubble in idling anymore, but after revving high it tend to geyser up and spill everywhere (i was using small funnel, gonna buy the lisle funnel kit tomorrow )
For all radiator work I use this funnel it makes bleeding less messy with no wasted coolant. The $26 was money wisely spent

1664791692367.png
OEMTOOLS 87045
 

dalai

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Sep 4, 2022
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Dalai, a video would be helpful of your trans issue.

Sorry could you hear it from link above? I am having trouble uploading audio file into here.

Its like cat or dog whining. Not so loud,
(Other sounds are just due to my phone mount moving)
 
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