Subaru Outback Forums banner

1 - 9 of 9 Posts

·
Registered
Joined
·
5 Posts
Discussion Starter #1
Howdy Folks. So I have a 2010 Subaru Outback Limited, 4 cyl AWD and automatic primary. I bought it as second user at 23k and didn't have any major problems until 150k miles. At that point it was the start of my nightmare. In short, OVERHEATING. Problem is, no one can figure it out it looks like. I drove it across 23k miles more before it went caput back then (through 2016). Back then I worked with our local mechanic and what all we did was this. We replaced the water pump, the radiator, the radiator cap, radiator hose to reservoir bottle and also the thermostat. He determined back then that the thermostat wasn't kicking on when it was supposed to. We initially bought a Subaru model thermostat and installed it, still overheated. Replaced it with a faster open threshold (an Oreily purchase) but it still overheated. At that point he just went ahead and gutted the thermostat so it at least kept it from breaking down on me. That's where I drove it for the 23k more miles before I had to shut it down indefinitely. I was dumping however 2-4 gallons of coolant into it a week (I know a major bad idea but I seriously needed a vehicle for my job as I traveled about 1k a week). At some point that year we did take it to the Subaru Dealership and after about a half hour of investigating they couldn't determine what the problem was. They even tried to charge me for a full hour of something like $100 for an "I don't know."

So it sat there then for roughly a year until my father and father-in-law agreed to chip in and see if we can get it back to working condition. Took it to a different local mechanic who put a massive amount of labor into it (about $1,300 or so initially then). This included the following (according to the receipt);
Removed, resurfaced and replaced heads. R & R water pump + serpentine belt, thermostat, intake gasket, plugs and wires,
timing belt, 2nd tensioner, fixed alternator wires, changed exhaust gaskets, charged battery (and actually replaced the battery too), changed oil and filter, flushed coolant system


They seemed to get it to work back then. They did an idle test for the better part of the afternoon and it didn't overheat on them. Then sent it back to my dad whom detail cleaned the vehicle and had it idle an additional 6 hours back then as well. No problems. Well we had it in hand for about a couple of days before the overheat sensor light starting blinking on again and became an issue. All in all, they've returned it back to my hands 4 times in the last month and a half and I am going to return it now for a 5th time. In that time they also replaced the inbound 02 sensor (from a error code reading stating this)(still overheating), then replaced the radiator (because apparently it had some leaks, ok) (still overheating), and recently burped the system of any air pockets.
At this point (after burping the air pockets) I had requested that they do the highway test like the way I do it. This means taking it about a mile into town then drive 2 miles up to the next highway exit and turn around. In that distance it's a decent little hill and I take the car up to about 80-85 miles an hour to make sure it gives the engine a good test. They said they did the test drive after burping the system and no overheating was happening. Well I picked it up that day, test drove it the following afternoon and I didn't even get to the highway before it overheated on me.

The only other thing I can think to say is that when it is running the heater is working. Seems to be fine usually at an idle. Then as the overheat sensor goes off the heating drops off entirely. When the car gets to the point where it overheats too much it typically pops the cap off the reservoir bottle from too high a pressure. At that point it typically is already draining the coolant out of the bleeder hole hence the frequent add to the coolant.

ANY experienced advice on this would be seriously appreciated. For some reason I suspect it has something to do with the thermostat not opening when it is supposed to and wonder if there is a sensor or computer somewhere associated with it causing the malfunction, but this is stumping now 3 different car experts :(.
 

·
Registered
Joined
·
22,836 Posts
Radiator packed full of bug carcases? Over heat sounds like it runs long enough to heat up the entire volume of coolant with little to no cooling happening then bingo temp warning light.

150,000 miles is where things like radiator fins are full of dirt and bugs, rubber parts start to have failures etc.
 

·
Registered
Joined
·
5 Posts
Discussion Starter #3
After those miles and so many places that I have been to yea, it was likely fully of bugs before it's been replaced now twice. Once when we first dealt with the problem and the 2nd time after the car completely broke down and they replaced it again here a couple of weeks ago.
 

·
Registered
Joined
·
22,836 Posts
Broken water pump not circulating coolant. Or due to the 23,000 driven on a blown Head gasket you have a leak within the block still possibly due to repeat over heats vs the original cause may have been or triggered the HG failure.
 

·
Registered
Joined
·
22,836 Posts
Just as a reference my Toyota head gasket failure was a $8000 job to fix and it was done twice in two yrs first time it wasnt done correctly. My cousins vw was a $4000 head job.

$1300 is even below the freinds and family $1500 Subaru often comped people in past yrs with faulty gaskets.

$1300 is still money but in the terms of blown Head Gaskets is pocket change.
 

·
Registered
Joined
·
5 Posts
Discussion Starter #6
True enough and no small feat. These guys do advertise as being the best price for the time in town. It's hard to tell if it's the water pump broken if that were the case since they did replace it. Any chance that it was installed incorrectly or just a faulty product? The replaced water pump the first time didn't fix the overheating issue and they replaced it again with all the changes back now a 1 1/2 months ago. It hasn't been driven much at all since the ultimate break down a yearish back and not all that much either since they did a complete repair so far. They did resurface the heads so that's possible. Would a crack in the engine block cause the overheating issue? And if so is there a surefire way to determine that?
 

·
Registered
2005 OBXT Limited, VF37, STI intake, 5MT
Joined
·
1,553 Posts
Where the second mechanic (the one who did the head gaskets) get the thermostat and head gaskets?

When it overheats, let it cool down and do not touch the overflow bottle or radiator cap. When cool, note the level in the overflow bottle. Then open the rad cap and note the level of the radiator (as best as you can).

If you're to-the-brim on the overflow bottle and missing coolant in the radiator, you likely have bad head gaskets (or weren't repaired properly).

When the EJ head gaskets let go, they can idle, low speed operation, or gentle driving all day long without problem. It's when you increase the load (and cylinder pressures) that they shove exhaust gas into the cooling system and start displacing the coolant. This causes loss of heat, overheating, loss of coolant in the radiator, and puking from the overflow bottle.
 

·
Registered
Lawn ornament XT
Joined
·
14,366 Posts
Did they use the right thermostat? Subarus are picky, they want the OEM part instead of an aftermarket item.

Heater core flowing properly? Even with the right thermostat, it won't get hot enough to open if there's a sediment blockage in the cabin heater loop.
 

·
Registered
Joined
·
5,867 Posts
Has an infra red thermal gun been used to confirm the engine truly is overheating and not a faulty temp sensor?
 
  • Like
Reactions: rasterman
1 - 9 of 9 Posts
Top