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Tribeca moderate overheating --resulting= engine replacement -

65K views 47 replies 23 participants last post by  tdelker 
#1 ·
So my wife drives our Tribeca 06 and she noticed that the temperature gauge was rising (but never red lined) while driving down the highway (in winter time). So we took it in thinking it would just need a thermostat replacement. Well they replaced the 'stat' but that didnt' help. They said it looked like the coolant had particulate matter in it (like large pepper flakes). They asked if we had had the coolant flushed. We had...by our subaru dealer. So they thought the problem might be in the head gastket. They had the head sent away to be looked at under high pressure conditions and it was not a problem. Oddly enough they were saying that one side of the motor was running 30 degrees warmer than the other side but had no explaination. They replaced the coolant and ran the car for 15 minutes and had the coolant sent off for testing. Apparently, it had a lot of exhaust gasses in it suggesting there was something wrong deep down in the engine....result....alot of hassle and we are now having to replace the engine. Has anyone else run into this problem. We have taken very very good care of this car and we are at a loss to figure out what is going on...and apparently so are our local subaru dealer and the subaru corporation as the dealer has been in contact with the "main" engineers. So I would love to hear if anyone else has this issue.
 
#28 ·
Quick update on my overheating situation. It appears I solved the problem myself by replacing the radiator cap last Friday. Prior, any driving would result in overheating. After I replaced the cap, not one single overheat episode. Here's the thing: I had the radiator replaced by the dealer about 3 months ago. I assume the new radiator came with a new cap (at least it looked new when I replaced it last Friday). If it was new, I suppose it might have been defective?
 
#32 ·
Simple $10 FIX

$10 and FIXED! I own a 2006 Subaru Tribeca and it had been getting hot at idle or lower RPMs, I noticed it was fine for the most part on the highway or revving at higher RPMs unless it got extremely low on antifreeze over time. I haven't had this type of trouble After replacing my radiator and thermostat over a year ago due to a coolant leak but was dealing with it yet again. I replaced the thermostat yet again and performed a pressure test and found no leaks but still got very hot, one bar to overheating but never had I let it get to that point. The design of the water pump had me convinced it wasn't likely to be the problem. My fans were working and a test showed they cycled different speeds as designed. I was told head gasket and was ready to spend $2500 to properly do the job. It was explained to me that the head gasket let air in the system and an air pocket would form near the thermostat that would cause it to not open properly and revving the engine forced the air pocket out and would allow the vehicle to cool back down with the thermostat opening properly again, until another air pocket formed. THANK GOD! I didn't get the head gasket fixed. I noticed the coolant reservoir was low and as I was filling back up the system I removed the radiator cap and that's when I noticed a very small quarter inch section on the inner side of the seal had separated. The entire seal or gasket on the radiator cap looked fine except this tear that wasn't noticeable unless I pulled on the seal. Went to Autozone and I picked up a $10.00 replacement radiator cap, a month has passed and the system hasn't lost a drop nor has the temp passed normal, as a matter of fact most times it's a bar under midway. Problem was daily or ever other day at best and with no issues in a months time, no doubt problem is solved. My heart goes out to all those who spent thousands only to not rid themselves of the problem. I've heard some after spending thousands some trade the vehicle in because it remained an unsolved issue. Guys get a new radiator cap, bleed all the air out the system before you tackle any other possibilities with the coolant system. You may find just as I have that a defective radiator cap is letting the air into the coolant system that ends up forming a air pocket near the thermostat. Even if the seal looks fine, for $10 replace anyway. The spring could be bad allowing air in just the same.
 
#36 ·
it's hard to definitely say a headgasket is ruled out on EJ25D's and EZ30's. they can go months without symptoms.

i've had lots of Subarus with torn radiator cap gaskets (my EZ30 has one right now) and no overheating. i'm sure it's possible for some to exhibit symptoms and others to not, so that's not definitive either, but in my experience a torn gasket doesn't always (actually i've never seen it happen yet) result in overheating. im' not saying i don't replace them though, that would be silly.

sometimes a cap or tstat is combined with a proper removal of air pockets caused by the failing headgasket. and maybe the change mitigates things for a bit - but a recurrence of symptoms is all-to-common.

story after story like this too and there's lots of threads/posts like that as well. a "repair" fixes it. just look two posts up - at sweetpete's - good for two months. happens all the time, i could tell stories i've seen but who wants to read it all.
 
#37 ·
Hey all, over the last few days I've been experiencing what has been described here, moderate overheating while stopped that goes away once I resume moving. I was wondering how it all ended up for those of you who had this problem. Did replacing the throttle body gasket cure the issue? Or is this a symptom of a larger problem? A fellow on YouTube with a video about the throttle body gasket on a Tribeca said the issue was ultimately the catalytic converters going bad and causing exhaust to back up into the engine.

I'm interested to know what the mechanic charged to replace it vs the difficulty of doing it myself. Is there anything I need to know to do it myself, or is it just a matter of taking the car apart and reassmbling with a new gasket?
 
#38 ·
There are multiple threads on this forum that you can go through and see the end results, but generally speaking, the only definite fix I've seen anyone report for the overheating issue is replacing the HGs... and not to toot my own horn, but that was by yours truly (HG's were swapped at 148k, 2+ years later I'm getting ready to roll over 200k and my coolant temp hasn't gone above the center line even one tick yet.) But that doesn't mean replacing HGs is going to work for everyone... some people who did replace HGs ended up with some recurrence or related issues, so it's not a fix-all for everyone.

That said, the throttle body gasket is an easy swap, but requires moderate disassembly. Thermostat and radiator caps are cheap and easy jobs that might be a fix. But before going through all of that, a simple "funnel" test for bubbles in the coolant will indicate your eventual fix will require new HG's (at least).

I have not seen the YouTube video, but I wouldn't even consider changing catalytic converters unless you have a known problem or deterioration. Certainly not something I would do to fix an overheating issue absent any DTCs.
 
#42 ·
So did the throttle body gasket stop the overheating? Question was asked a few times on the video. I swapped a JDM engine in (mostly due to settlement money), but I'd still like to know.
 
#43 ·
throttle body gasket replacement fixes overheat at idle

Early posts by me describe my experience with overheating at idle that goes away when the engine is revved. The dealer attributed this to a warped head; replacing the throttle body gasket fixed the problem.

Within the last 2 months, I noticed a friend of mine was driving a Subaru Tribeca. I mentioned the overheating problem I had seen with mine and he told me that his was doing the same thing. I mentioned the throttle body gasket as a possible source. His mechanic changed the gasket (charging about $150) and the engine is no longer overheating.

The symptoms that are repaired is an overheating that appears at low engine RPM, with normal temperature returning after the engine RPM is increased.
 
#46 ·
I had the same problem moderate overheating at Idle and stop lights. My 2007 tribeca has 340,000 miles on it (you read that right) it has overheated a few times due to a busted radiator hose, bad radiator cap, and once the upper radiator hose just popped off. I was sure I needed a head gasket or had a small leak. NOPE thanks to this post I changed the thottle body gasket and it has rectified the issue! Thank you so much!
 
#47 · (Edited)
Was there a loss of coolant at the radiator during these overheatings as well? I replaced my engine with a jdm one due to overheating and now I am experiencing loss of coolant at the radiator even with a new cap and overflow hose. I am not getting any overheating at all YET but curious to see if the TB gasket could work a miracle for me. Thanks.
 
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