CorneliusJones Posted May 3, 2017 Share Posted May 3, 2017 Hello and thanks for taking the time to read this. I own a 2007 legacy 2.5se with 119,xxx miles. My car has been through a lot in the past year and I'm having an issue with the coolant temperature gauge. I'd like to elicit some opinions from owners more knowledgeable than me. The short version is this: My temp gauge hovers below the halfway point, about 3/8ths from the bottom. The temperature gauge rises to the halfway point for a moment, then falls to the 3/8ths mark. The gauge stays at this point no matter how hard I accelerate or if I coast, but will rise with idling, albeit slowly. Engine temperature rises to the mid point (then right down to the 3/8ths area) after about 4 minutes of driving. The problem started with the engine temperature reaching the mid point, and remaining there under normal driving conditions; when I would accelerate hard, the engine temp would rapidly drop to the 1/4 mark, and recover when I would drive normally. Suspecting a bad thermostat, I purchased a factory spec replacement. I removed a stant thermostat and felt relieved that I had likely solved the problem. I replaced the thermostat, refilled the coolant and burped the system three times over a few days (no air on the second and third attempts). The factory thermostat is in the car now. I boiled the stant thermostat, and it opens and closes without sticking. I have good heat available at all times (162F measured by meat thermometer :0). I do not have any check engine lights. I have new head gaskets, a new radiator, new timing belt, water pump and a new factory thermostat. When running, both coolant hoses are hot Radiator fans only come on when the ac is running. No leaks that I can find. I sometimes smell a hint of coolant, but that may be from spills when I burped it. No white smoke Oil and coolant are clean No overheats Coolant is full The engine is a rebuilt block (see below for the gory details). Gory Details About one year ago, I took my car in to get the timing belt, water pump and pulley replaced around 109,xxx. I had a small oil leak on the top of the block for almost two years at this point. Shop does timing belt service, and says head gasket is bad. Have both jobs done. Mechanic takes my car for final test drive, while on the the way back, the valve train plug on the back side of the engine falls out (someone forgot to bolt the cover back on :/), oil pressure is lost on the driver's side head, head is ruined. Shop replaces head and associated parts at their cost. Car still wont run right, so the shop buys a rebuilt long block (with 3 year warranty) at their cost. I get the car back, and all seems well. About 1,000 miles later, I start getting intermittent overheats. I take the car back in and a radiator leak is found. New radiator is put in, at a very good price. After about another 250 miles, the engine starts overheating again, but not intermittently. I limp the car back in, and the head gaskets are bad (again). The shop pays to have the engine taken out and overnighted to the manufacturer, who confirms a bad batch of head gaskets. Engine is overnighted back, put back in, and I get the car back. All seems well, until I notice the precipitous drop in engine temp under hard acceleration. I deal with it for about four months, as the car runs fine, pumps out heat, and no CELs appear. I end up changing the thermostat for a factory spec and that is when the current issue appears. For the first 109,xxx miles, the needle was dead center. I don't want to miss anything that could lead to bigger issues. I have done a significant amount of reading and I think it either has to be the thermostat or a bad temp sensor, but I don't want to spend anymore money either! Thanks for reading this and let me know if you have any questions or ideas! Corey :confused::confused::confused::confused: Link to comment Share on other sites More sharing options...
NORULZleggy Posted May 4, 2017 Share Posted May 4, 2017 Is the thermostat a Subaru one? cause you keep saying factory replacement. Go to rockauto.com get a temp sensor. I had this happen. under hard run the needle would go a bit lower but not much, then back to normal. I never saw an issue, car never ran bad. I would drive the car and keep an eye on things, check all fluids every week and if there car is running fine then don't stress over it. replace those parts. Get a Subaru t-stat if you did not go there to get one. Link to comment Share on other sites More sharing options...
CorneliusJones Posted May 4, 2017 Author Share Posted May 4, 2017 Thanks for the reply, the current thermostat is an oe Subaru one. If I drive the car hard, the temp will not budge either way. If I idle, the temp will rise to the halfway point, but decrease to the 3/8ths mark when driving. It's really confusing! I think I'll probably replace the thermostat again and swap out the temp sensor too. I must just have bad luck at this point. Link to comment Share on other sites More sharing options...
NORULZleggy Posted May 4, 2017 Share Posted May 4, 2017 Flush the whole cooling system, replace the t-stat, and temp sensor. is it a bit below the half point? cause mine was never at the half way point. Link to comment Share on other sites More sharing options...
CorneliusJones Posted May 4, 2017 Author Share Posted May 4, 2017 Yes, the temp gauge is a halfway between the 1/2 and the 1/4 mark. I may end up just doing what you suggested, I cannot think of anything else that could be contributing to the problem. Link to comment Share on other sites More sharing options...
CorneliusJones Posted May 6, 2017 Author Share Posted May 6, 2017 Well, in hindsight it makes perfect sense, but I did get the problem fixed and it was the thermostat. I did purchase a Subaru thermostat online and it is exactly the same in every way from the one I purchased from the dealer except for one minor detail.....the dealer purchased one was rated for 82c and the one I purchased online was rated for 78c. Makes all the difference Everything is working as it should now! Link to comment Share on other sites More sharing options...
MilesA Posted May 6, 2017 Share Posted May 6, 2017 Glad you got that one figured out. BTW, what car is that in your avatar picture? Link to comment Share on other sites More sharing options...
CorneliusJones Posted May 7, 2017 Author Share Posted May 7, 2017 It's a Morgan three wheeler. Very cool car. I don't own one, though. Maybe some day..... Link to comment Share on other sites More sharing options...
Recommended Posts
Archived
This topic is now archived and is closed to further replies.