jonesyb84 Posted March 2, 2018 Share Posted March 2, 2018 Hello fellow Scoob owners! I'll cut to the chase: Impreza, 2.5i 2007 Sedan 150,000 miles. When I drive hard (ie hold revs to roughly 4000rpm), something will happen whereby when i begin to slowdown, or reduce revs, it begins to overheat, (even if i idle even when in motion). Maybe I'm being a little specific here, but it will begin to overheat. I got home and felt the lower rad hose (by the thermo) and it was cold. I then bled the system of air after and everything seems to be ok until I repeat the action again. The head gasket has been recently changed with all new seals and gaskets, along with thermostat and rad cap. I'm completely at a miss here, any ideas? Thanks in advance! Quote Link to comment Share on other sites More sharing options...
Rooster2 Posted March 2, 2018 Share Posted March 2, 2018 Water pump, or possibly radiator somewhat plugged up. Ever use stop leak additives, or fail to change antifreeze for long periods of time? 1 Quote Link to comment Share on other sites More sharing options...
GeneralDisorder Posted March 2, 2018 Share Posted March 2, 2018 Non-dealer thermostat, partially clogged radiator, cheap water pump..... check them in that order. GD 1 Quote Link to comment Share on other sites More sharing options...
idosubaru Posted March 2, 2018 Share Posted March 2, 2018 Make sure theres no air in the cooling system. Monitor how much fluid loss is happening. I always try to determine if it’s overheating related to low coolant level or something else. Who did the headgaskets and what brand gasket was used? What’s the story of the car - car that you’ve known for years and never overheated before or a well used and unknown Craigslist’s special you bought yesterday? 1 Quote Link to comment Share on other sites More sharing options...
jonesyb84 Posted March 2, 2018 Author Share Posted March 2, 2018 (edited) I've checked the thermostat and the water pump is brand new. I'm mostly concerned about the lower pipe going from the thermo to the rad being cold until i bleed it. How would a clogged rad effect this? (Im just trying to get a handle on this before switching part out).Elite Master: I've owned the car for 2.5 years now. I'll monitor any coolant loss, but i don't think there is any. The gaskets were changed by a local garage - i'll find out the brand used. Edited March 2, 2018 by jonesyb84 Quote Link to comment Share on other sites More sharing options...
1 Lucky Texan Posted March 2, 2018 Share Posted March 2, 2018 as mentioned above the thermostat is OEM-style? 1 Quote Link to comment Share on other sites More sharing options...
jonesyb84 Posted March 2, 2018 Author Share Posted March 2, 2018 Ah...I do have an aftermarket thermostat in place. The oem version looks far more robust and after some research could be the issue. I'll switch it out and report back. Quote Link to comment Share on other sites More sharing options...
1 Lucky Texan Posted March 2, 2018 Share Posted March 2, 2018 some aftermarkets may be OK, there is a specific Stant part number that many folks have used. but, typical t'stats are a known problem. 1 Quote Link to comment Share on other sites More sharing options...
GeneralDisorder Posted March 2, 2018 Share Posted March 2, 2018 TAMA is the OEM for thermostats. Generally these aren't sold outside wholesale channels though. Easiest source for most people is the dealership. GD Quote Link to comment Share on other sites More sharing options...
jonesyb84 Posted March 2, 2018 Author Share Posted March 2, 2018 On my way to pick up an OEM version now Quote Link to comment Share on other sites More sharing options...
jonesyb84 Posted March 6, 2018 Author Share Posted March 6, 2018 Update: I got the old thermostat out, and yes, it was an aftermarket version. Also, the person who had been there before had placed the air bleed valve at the '9 o'clock' position rather than 12. It all seems to be good so far with an OEM thermo fitted correctly, but i really havnt had the chance to take the motor on a longer more strenuous trip yet.....I'll report back. 2 Quote Link to comment Share on other sites More sharing options...
impostor Posted March 7, 2018 Share Posted March 7, 2018 Wow, someone else from Omaha on here!? Give me a call at my shop, Russ' Garage, if you need us to take a look at it. 402-681-5128. I won't be able to offer much help this week though as we're a 1 man show (me) due to a family emergency. 2 Quote Link to comment Share on other sites More sharing options...
impostor Posted March 7, 2018 Share Posted March 7, 2018 Make 100% sure all the air is bled out of the system. These newer ones with the vertical intake runners after the throttle body seem to be a little bit more difficult to bleed than the earlier ones. Make sure the overflow bottle hose is not clogged and the bottle isn't full of crud at the bottom. I also make it a habit to trim the bottom of the hose at a 45 degree angle so the hose can't suck itself to the bottom of the bottle (there was a tsb about this and at some point Subaru changed the hose to have the angle in it) Also verify that the coolant level in it is rising and falling as the coolant heats up and cools back down. Jim 2 Quote Link to comment Share on other sites More sharing options...
jonesyb84 Posted March 9, 2018 Author Share Posted March 9, 2018 I hate it when threads have no ending, so here's the conclusion: Took her out on a long run and all good. OEM thermo and correct installation did the trick. Obviously the water wasn't able to get through the small gap in the aftermarket thermo and it probably wasn't completely bled of air. Thank you everyone! Now off to the next job 2 Quote Link to comment Share on other sites More sharing options...
GeneralDisorder Posted March 10, 2018 Share Posted March 10, 2018 Oh I knew what the conclusion was going to be. But thank you. GD 1 Quote Link to comment Share on other sites More sharing options...
idosubaru Posted March 10, 2018 Share Posted March 10, 2018 I hate it when threads have no ending, so here's the conclusion: Great, glad you got it. But be sure to report back if anything changes. there's plenty of "i thought my overheating was fixed" scenarios. 1 Quote Link to comment Share on other sites More sharing options...
jonesyb84 Posted March 10, 2018 Author Share Posted March 10, 2018 Great, glad you got it. But be sure to report back if anything changes. there's plenty of "i thought my overheating was fixed" scenarios. Of course! thanks Quote Link to comment Share on other sites More sharing options...
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