amhawks

+1 to my OCD, eh? Well good, it finally paid off! I won't gloat it too much, my wife will get sick of it fast. Just curious, what temp constitutes overheating?

Hopefully. It still makes me wonder if I will have any problems in the (near) future. Thoughts?

Reporting mine was the t-stat too (aftermarket garbage) not a subbie. By the genuine part for the t-stat…..

I had a chance to work on the car today. Problem fixed. It was the t-stat. It was one of those crap aftermarket ones. I could tell as soon as I removed the t-stat bracket (no air passage 'float valve') and even more when I pulled it out (short, copper, lightweight spring…garbage). I really don't understand why the aftermarket company even makes this garbage AND I don't understand why the shop who I got the car from even claims they use 'genuine Subaru parts'. I have a shop in Eastern Oregon I know I won't use anymore. The thing I wonder is for nine months that car has been running 'hot' (104 deg C). Makes you wonder how long it could of held it up, not that's I want to find that out either! Vasy: Thank you for the report. My numbers are similar, now.

The heater blows hot air all the time. I didn't see any bubbles when I checked previously, but tonight it was getting too dark to look. The non-OEM t-stat was something I was going to check. They 'said' they put in subbie parts, but I didn't see it before it went in. Depending if I can get one tomorrow I planned on checking that just because that's the cheapest route! I have a used one that I swapped in from '96 2.2 years ago (routine) that has been sitting in the box…does anyone know if the 2.2 and the 2.5 are the same t-stat?

Ahh, that makes sense (and makes me feel potentially better about my situation). I thought/think I am in the HG nightmare right now, but I ran mine up a pretty good pass (over the Blue Mountains on I-84 out of Pendleton, Oregon) and it ran just fine on the temps. It heats up just a bit (to 105 deg C) when I am on the flat terrain. I just started a new thread regarding this issue.

Hello, Long time 2.2 subbie owner - been in a 2.5 for about 9 months. The 2.5 I am driving is a 99 outback (DOHC). About 10-9,000 miles ago a subbie shop in town here changed the HG's, timing belt, t-stat, radiator, and all the associated parts with that maintenance. The HG's were bad at this change and the heads were checked at a local machine shop (all OK). Last week (when the whole Nation was freezing cold) I was headed back from Portland (4.5 hour drive). At about 3.5 hours into the drive I noticed my temp gauge was slightly higher than where it normally resides (It was only a few tick marks about the middle). I found that if I accelerated (higher RPM's), it dropped to normal operating temp. In the morning I finished my drive and noticed the same symptoms (lower RPM's and the temp would creep up just a bit, higher RPM's and the temp would reside in it's normal spot). I finally had time to plug my scan gauge into it tonight and while fusing at highway speed (55 mph, 2,000~ RPM's) I would get a constant temp of 104-105 deg C, If I'd push a higher RPM it would drop to 100 deg C, or even get in around 97, 98, or 99 deg C. Cursing through town it would ride at 105 deg C (25 mph) and sitting parked in my driveway it would ride back down to 97 deg C. Both radiator fans are running just fine. Any thoughts? HG's, again? T-stat? Was it the single digit temps that pushed it over? 105 deg C is too warm for me, hope it's not too warm for this car. It bounced up to 107 deg C briefly and returned to 105. Thanks in advance. 177K on this engine, HG's changed about 10K ago (heads checked too)

I understand this….. What I don't understand is why does a higher RPM not cause temperature to increase? I understand that a higher RPM turns the water pump faster, thus moving more coolant to cool the car. However, doesn't a higher RPM also equal more combustion gases being added to the coolant (and combustion gases is why a car can heat up with a head gasket problem)? It seems like it should either increase the coolant temperature, not lower it. Any thoughts for this greenhorn? Thanks.

Did he check the HG's and if so what test did he use?

A Subaru should run at the halfway mark on the temp gauge. It does sound like your t-stat is removed. That rattle is probably a heat shield, no biggie. Most Subaru's have that signature rattle. Best of luck and keep us posted on the diagnoses.

@MammaDuke: I'm curious on how hot the car is getting? You say they are going up, but how high on the gauge? @Everyone else who said HG's. I'm not challenging you, but if it was HG's wouldn't the temp go up with RPM's (thus forcing more exhaust gas into the coolant)? Or would the water pump spinning at a faster RPM suffice for cooling it to normal operating temp (if MammaDuke's car is even in normal operating range). Just trying ot put the pieces together in my head. Thanks.

That's what I was thinking from these results. I am going to have to trust my stock gauge until I get another tool or two.

UPDATE: OK, I have some reporting. - System did not hold pressure fir very long with my DIY tester. - Checked hoses and they were all tight. - Checked rear heater core and notice a drop of anti-freeze coming out near the valve (kinda odd since I just replaced the o-ring) - Decided to eliminate the rear heater for now and checked for pressure. - Front heater lines, at the T, started leaking - Decided to bypass all heaters and took line coming out of the coolant manifold (2.2 - reversed) and brought it straight back to the pressure bottle. - Checked system for pressure, it held air - no leaks detected. - Bled system, bled system, and bled some more. - Small air bubble in pressure reservoir, started it anyways. Bubble moved out of reservoir. - Ran engine to operating temps in the driveway, no bubbles detected. - Drove around the block a few times, no bubbles detected. - Parked it back in the driveway, no bubbles detected. - Engine stayed within operating temps on the VW gauge (middle to right below the LED) I am guessing no to the HG, yes to a leak in my system, probably rear heater core - I will change out hoses soon and probably just run the front heater until I feel more ambitious. NEW SCENARIO: All that has me worried is as soon as I shut the van off I heard fluid hissing. I looked under the van and noticed fluid dripping. Popped the hatch and saw fluid coming out of my pressure reservoir near the cap. Tried to tighten the cap down and the cap just spun and spun (stripped). This is an aftermarket bottle I got from an 'undisclosed' dealer as a replacement when their other bottle did the same exact thing. Having the bottle blow up like that makes me either think it is: A. Cheap bottle or B. Head gaskets I can't give you temps other than what is on the VW gauge (sorry) and what I feel on the bottle itself (bottle is warm, not super hot). There were no bubbles in the pressure reservoir present when this happened.

You may be right on with this one. I will pick up some parts tomorrow to bypass the heater. I noticed a few drops of antifreeze their tonight. I also did a pressure test on my coolant system and it would not hold pressure when added and there was no increase in pressure as the engine ran and revved up to 3K. I'll keep you all posted.

Yes it is obd2. My scanner is just a code reader. I wish I had a different type. $100 more, but in the end I think they are worth it.