Outback Overheating

anonymouspilot · Post by **anonymouspilot** » Sun Feb 28, 2010 10:22 am

My very recently purchased '99 2.5L Outback has a few overheating issues, and any ideas would be greatly appreciated.

It runs fine but every so often the temp will spike up, it will either fix itself and drop back to the normal range or I have to stop and let it cool down. This is happening more frequently to a point now where I cant get more than a km or 2!
The fans are definitely coming on (it overheats at freeway speeds too), I've changed the thermostat and flushed the system, the rad overflow often fills (to overflowing) with warm/hot coolant. A few revs with the rad cap off sees some water come out, and although that points to head gasket, there are no other indications, runs great, clean oil, and isn't overheating consistently.

Its new to me and don't know a lot about these subie things, so any suggestions would be fantastic, Thanks.

Post by **TOONGA** » Sun Feb 28, 2010 10:27 am

yep I would say head gasket the 2.5s were prone to it for some reason

looks like it is going into the cylinder side not the internal (oil) side

TOONGA

anonymouspilot · Post by **anonymouspilot** » Sun Feb 28, 2010 10:38 am

Thanks for the speedy reply toonga,
Any idea how i can test this easily? Comp test?
And how big a job are we talking to get one (or I guess 2 really) done?
Also, ive heard when the head gas goes, they really don't run well...is this not always the case?
Thanks again.

Post by **TOONGA** » Sun Feb 28, 2010 1:31 pm

if it is leaking into the cylinder the easiest way to find out is if the exhaust constantly steams, or to pull the plugs and turn the engine over if it is bad water will come out the plug hole.

a compression test will tell you if there is high or low compression in the cylinders, there is a test where by a pump device with a gauge is fitted to the radiator (this is done without the engine running) and pumped to the engines recomended running psi/kpa then left and watched to see if the pressure drops if it does the cooling system has a leak.

normally if one of my head gaskets go I do both (I did one put the engine back in and then the other one went)

TOONGA

Jeff · Post by **Jeff** » Sun Feb 28, 2010 4:34 pm

Put a H block in the heater hoses,this allows water flow thru the engine without the restrictions in the heater core and lets enough water thru the heater for it to still work.
Libertys , Outbacks , Impreza and Forester don't have a heater tap in the engine bay like MYs and probably Ls
Try that before assuming the worst

RSR 555 · Post by **RSR 555** » Sun Feb 28, 2010 5:10 pm

I'd be making sure you don't have an airlock in the system. I've found this happens lots on the Subies. I would suggest you check this first. The next is to get a local Radiator shop or Mechanic to test the system with a Tee Kay test kit. It will show straight away if you have Co2 in the cooling system from a head gasket leak.

anonymouspilot · Post by **anonymouspilot** » Sun Feb 28, 2010 6:25 pm

Thanks for the replies, I've got a few things to try.

Jeff, is it common for this model to have heater flow problems? The coolant I dropped was pretty filthy.
RSR, I thought of an airlock, but the problem first surfaced after about a 500km (uneventful) freeway trip, without the coolant system being opened, tried to purge the system by jacking up the front when refilling the coolant (after replacing the thermostat) and there was pressure through the hoses, will take another look tho...

And just to prepare for the worst, has anyone had the head gasket done? and what can I expect as far as price and/or labour time? Do they always remove the engine (I believe thats recommended) or can it be done left in?

Cheers, James

Jeff · Post by **Jeff** » Sun Feb 28, 2010 7:09 pm

Yes i have seen a lot with this problem, even bought cars off people who have self diagnosed head gaskets and put H blocks in and no more problems. You can buy plastic Tees from Gates the right size and a couple of clamps , 4 " of heater hose all for about $20 and try it. It may still be head gasket but from your description i doubt it.

anonymouspilot · Post by **anonymouspilot** » Sun Feb 28, 2010 7:18 pm

Thanks heaps, certainly worth a try...

AlpineRaven · Post by **AlpineRaven** » Sun Feb 28, 2010 7:42 pm

Check for airlocks in the system, best way to release is to tilt the car (best find a small hill and drive the car up the hill, pointing the release valve towards top of the hill)
Other thing you might have blocked radiator.

These 2.5 litre SOHC in 3rd gen outback doesnt really have headgasket problems alike Gen 2 DOHC did have.
Cheers
AP

RSR 555 · Post by **RSR 555** » Sun Feb 28, 2010 8:23 pm

anonymouspilot wrote:And just to prepare for the worst, has anyone had the head gasket done? and what can I expect as far as price and/or labour time? Do they always remove the engine (I believe thats recommended) or can it be done left in?

Cheers, James

James.. I'm still leaning towards airlock in the cooling system because just running around the corner to the shops or work sometimes doesn't show the signs of overheating. The other thing to remember is the water temp sensor must have water on it to show correctly (steam won't) but I don't think your level is that low. I used to use the hill trick (until I got a hoist) to get the airlock out. I'd try this first.

As for cost involved in doing your head gaskets.. well how longs a piece of string but I did it for a good friend 6 months ago and all up it was just over $1,000 but this can differ due to quality of parts and work that is subed out (Head facing), also things like radiator service, hoses, etc... And I found it shit loads easier to remove the engine because they are flat engines, the head bolts are more difficult to get to than most other cars.

Best of luck and let us know how it all turns out.

Outback bloke · Post by **Outback bloke** » Sun Feb 28, 2010 9:03 pm

The 2.5 in that model is renowned for head gasket issues. I think it would be the gaskets BUT do what the other have suggested before you start pulling the engine out.

Very first thing I would do is pull that new thermostat out again and cut the guts out of it. I have seen many new ones fail. This will also get rid of any air blockages. It is also the cheapest spot to start as you don't have to spend a cent to try it.

Then I would be going to a radiator shop and getting the test done. Again next cheapest as it will probably be free. It will tell you 95% of the time if it is a head gasket issue.

If it is not head gaskets then do the H block thing. This too is also very cheap although I do think it is treating symptoms not the problem. They didn't do it when new, so some thing is either blocked or not working.

Yes it is possible and also very common for the gaskets to only blow between compression and water. The gaskets are more than often more like they are fatigued and degraded rather than blown from overheating. They can also be quite difficult to tell where they where not sealing.

If you do the work on the heads yourself you will be looking at $120 to have your heads hardness tested and skimmed.

Shop around for gaskets to get a good price. Blackbox motorsports/Justin - one of our sponsors should be able to sort you out with a decent price.

You will need a tube of silicon for sealing around the cam covers in the corners. Ultra-blue is what it is called. Around $20

You will need to change the oil and filter. Filter $20-ish. Oil depends on your preference.

Coolant $15

If it is auto, you will also lose some tranny fluid. Allow another $20 for that.

Also need a new thermostat seeing you destroyed it earlier on.

If you pulled the motor on a Sunday, you could have it stripped by that arvo. Pre-arrange with a workshop to drop the heads off Monday and you will have them back Tuesday. Put the motor together after work during the week and it will be ready by Friday for you to put it back in on the weekend.

anonymouspilot · Post by **anonymouspilot** » Mon Mar 01, 2010 10:08 pm

Well, after a sh!t weekend, I was forced to abandon the Outback in Syd to return home for work...
Was able to get the coolant tested for CO2, with no indication of head gasket problems, also cleaned and flushed the rad (and purged by someone who apparently knows what they're doing?) with no indications of a significant blockage. Didn't get a chance to do the H block on the heater.
The temp again went up after about 20min driving...
Anyone heard of water pump issues with this engine???
Thanks for all the info, slowly narrowing down the possibilities, but will have to wait till next weekend now.

RSR 555 · Post by **RSR 555** » Tue Mar 02, 2010 6:54 pm

good to hear there was no Co2 in the rad

But I'd be checking the themostat (I think Brett mentioned it) because even a new one can fail.

As for the waterpump?? well it's a possibility but highly unlicky. I'd cut the guts out of the thermostat and run it around for a bit and see how you go.

Oh.. and last thing, are your fans coming on and off as normal when the car is not moving? as I wouldn't discount the temp sensor giving a false reading (just a thought?).

davidjones · Post by **davidjones** » Sun Apr 25, 2010 4:51 pm

This seems exactly what I have just dealt with.
Was a small leak on exhaust side in head,passed had all tests looking for blown head gasket. No systems of blown head gasket, no over heating. was showing bubbles in overflow tank.
Had both heads overhauled, problem solved.