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Discussion Starter · #21 · (Edited)
Thanks - OEM head gaskets used and heads machined. The shop still has the car - Once the HGs were changed they had called me to pickup the car (they had test drove the car and no more overheating problems). I came the next morning to pickup and when they took it out earlier in the morning it was starting to overheat. They then spent an hour burping (alternating between reving and idling and added coolant as needed). When I went to take the the car it overheated after a few minutes and I just turned around and gave it back to the shop.
 

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Let us know what they find. I suspect they screwed up, but the head might be cracked.

Does it happen that both the gasket goes and the head cracks at the same time?
 

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I do hope they took all of the shop towels out of the passages before putting the engine back together.
 

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I don't think anyone believs "never" when it comes to engines anything can fail. I was trying to be simple and not qualify everything - i could write a 3 page treatise for every headgasket thread or try to be as helpful and concise as possible.

Subaru non-turbo heads that haven't been significantly overheated, rarely crack, if they do it would be an outlier and not a go-to initial diagnosis or suspicion. It's so uncommon that there's probably a root cause or misdiagnosis. A Subaru non-turbo head that hasn't been significantly overheated with a crack in it - is an outlier.

If you find a cracked non turbo Subaru head you would need to verify that it's never been overheated prior to this event and that the current event didn't have unknown overheating before it was "caught".

So the real question becomes - how badly was this thing overheated? I was assuming by "towed it back" - the poster was inclined to avoid driving it in this condition. but that is a really poor assumption - so that would be a good question to address.

If that were a head on a car I wanted to keep another 100,000+ miles i would have replaced the engine unless i could somehow verify there were no significant overheating events in the life of the vehicle.
 

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Discussion Starter · #25 ·
My wife drives the car as a daily driver and I will usually be driving it on the weekends. I had not noticed any overheating in the past (although if it was just one tick above normal I might not have noticed). When it did start to overheat on our trip I noticed and monitored it until we could pull off the highway (10 minutes) - it went up between 1 and 3 ticks over normal - the overheating warning light never went on. After this it was towed back to my house and then driven 3 minutes to my mechanic (got 1 or 2 tick above normal during this drive) and then was towed to another shop. Hopefully will have an update from the shop it is at now (the one the changed the HG) in the next day or so.
 

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Discussion Starter · #26 ·
Also I bought the car new in 2008 so I have been the only owner and know the engine history up to this point.
 

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Discussion Starter · #28 ·
Just an update on my overheating problem - it is now fixed. In addition to the head gasket needing to be replaced I had a blocked heater core and even though the thermostat was originally replaced it was not opening completely. So the heater core was acid flushed and flow tested and thermostat was replaced again. From what I understand the thermostat needs flow from the "hot side" through the heater core in order for it to function properly (which seems like a bad design). Car is running fine now and temperature gauge does not budge from the middle line.
Thanks everyone for your input.
 

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Hate to revive this thread from the dead but I have a 2006 with a blown head gasket. It is overheating and has significant amounts of oil in the coolant. Oddly, it isn't overheating excessively but it is still cool outside.

The engine has 177K miles on it an my mechanic is hesitant to do the HG job on it. He is concerned that the block surfaces won't be good enough to get a good seal and it will just have more problems soon.

I am considering an engine swap. I can get one for $1200 plus shipping that has about 60K on it. The body is in OK shape but I can see that rust is in its near future.

What do you guys think?

If I do repair or swap, should I have the heater core flushed to be sure it is clear?
 

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It is common to swap with a known good H6 for subarus since the head gasket on the H6 is a lot more work than their H4's mainly because of the timing chain and having to remove both chain covers. So it's good advice.

Can't hurt to flush the heater core, but generally if its plugged you have to replace it from inside the cabin. There's a how-to somehwhere on here. I don't think it saves you anything to do it at the same time as the engine.
 

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It is common to swap with a known good H6 for subarus since the head gasket on the H6 is a lot more work than their H4's mainly because of the timing chain and having to remove both chain covers. So it's good advice.

Can't hurt to flush the heater core, but generally if its plugged you have to replace it from inside the cabin. There's a how-to somehwhere on here. I don't think it saves you anything to do it at the same time as the engine.
The big concern I have is with emissions. I am not sure the JDM engines on ebay have all the stuff needed for NY emissions.
 

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You can swap over a lot of the exterior stuff, but you do need to know it has all the right bits for the tribeca ECM to control. Hopefully someone with more knowledge can help you. Might try over on subaruoutback.org as they share the same engine.
 

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In comparison, Subaru motors have a tight piston to wall clearance so overheating does take its toll. Coolant in the oil galleys is pretty much the kiss of death on the bearing shells also.

It would be wise to seek out a jdm unit with lower mileage and transfer your ancillary controls/hardware. Budget a radiator so history doesn't repeat itself. It's a three ring circus to get the air out so bleed and bip the throttle preferably with the front raised a bit.
 

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The big concern I have is with emissions. I am not sure the JDM engines on ebay have all the stuff needed for NY emissions.
they do. same engine. no big deal, it's plug and play and bolts right up.

you can swap your entire intake manifold and hoses onto the JDM if you're ultra concerned.

oil and coolant don't usually mix in that engine. it's probably just dirt built up coagulating or exhaust gases dirty-ing up the mix. but if it is oil and coolant mixing, i'd never want to keep that engine. if I'm not familiar or trust how badly it was overheated, I don't want engines prone to headgasket failures, i'll just buy another one..which does incur a minor risk of course as well.
 

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Discussion Starter · #36 ·
Hi All, just reviving this thread - I am the OP - overheating issue is coming back but I am catching it early and want to nip it in the bud and hope it is something simple. Recently I have noticed hat after the car is warmed up and I stop at a light my temp will slowly rise - after a minute or so it is up to 106C and goes up one tick over normal on the gauge on the dash. If I rev the engine it will go down to 92C or so. Fans are working correctly and kick in when needed - no obvious leaks. I also note I am not getting a lot of heat from the cabin. Temp stays in the 90's C while driving. I don't 100% trust my dealers and the independent that fixed it last time in 2+hrs away so would like to try some basic trouble shooting or selective maintenance first. Was thinking to try flushing the heater core again?
Thanks in advance.
Daren
 

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I"m following this thread now. My 2008 Tribeca (with 145,000 miles) might be showing signs of HG failure. I think it's always reached the 3 skinny bars for the engine temp. It definitely leaks oil, but I"ll recheck whether any of the brown gunk milkshake is building up on the oil cap.

Not looking forward to getting estimates for this type of repair, but would love to have this vehicle last another 3 - 5 years.
 

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So this has started for me and it got me to thinking. Anytime I have had over heat I have been idle. This is true except for one time going 65 MPH down a hill and the temp gauge went from normal to top. This leads me to believe am issue with the fan control.

Overheating checks (2006) Overheating checks (2009)


Radiator Fan System Troubleshoot

A poor join in/at the control unit seems most likely as the event comes and goes.
I would be most interested in steps 4 to 6, especially as the connector moves. At idle, the connector may vibrate, or is making a poor connection always. The other option is a poor solder in the unit. Seems simpler than taking it to a shop, and may be cheaper.
 

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OEM Radiator Cap

I know all situations are different but I had this issue a couple years ago and it was fixed by replacing the radiator cap with OEM SUBARU, NOT AFTERMARKET.



OEM is between $10-$30 depending on where you buy it from but may be worth the money for your situation.
 

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Discussion Starter · #40 ·
@huskylord Just to give you some HG info since you are in Toronto - when I was searching in 2016 this is what the price range looked like (from dealership) $2.5k (Mississauga) to $5k (Budds) - used engine was also suggested ($1.5k + 10 hrs labour). John from Brampton Subaru was helpful - most shops were not experienced on this type of repair on the H6 engine. Ended up taking it to Autologix in Kitchener - Adam there knows the H6 engine very well.

Getting my heater core flushed tomorrow and will report back how that went wrt my overheating problem.
 
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