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Blown head gasket in 99 Outback?

10-15-2006, 03:27 PM
My Outback (-99) overheats sometimes (the temperature gauge shows high temperature and coolant leaks while the engine does not appear to be extremely warm, the radiator fans do not rotate).

The symtoms are:
1. You need to drive it completely warm and sometimes it does not even overheat while warm.
2. Sometimes as it overheats the overheating stops suddenly (the temperature gauge goes back to normal level)
3. It appears to be more prone to overheat while idling (for example the first time it happened, the temperature went to normal level immediately after I drove the vehicle).
4. There appears not be oil in the coolant (or coolant in the oil).
5. The radiator fans do not rotate when it is overheating.

The thermostat has been changed on it and my mechanic claims that it is the head gasket.

The strange issues (in my opinion) are:
1. How the overheating can stop while driving and not doing anything, if it is the gasket?
2. Why the fans don't rotate?
3. Why it appears to happen most often while idling?

Could it be that where is some dirt in the coolant that sometimes jams the thermostat which does not allow the water to circulate and causes the overheating?

Or are the symtoms in line with the head gasket problem?

10-15-2006, 04:03 PM
Pull the sparkplugs and check them for corrosion.

Is the coolant milky looking - this is also an indicator of head gasket issues.

Check the fans, sounds like there is an issue there with them coming on. If the temp goes back down when you're in motion and there is air flow around the rad, that's a definite sign to check the wiring and such on those radiator fans. Also may be a good idea to have a coolant drain and system flush in case there is debris in the coolant - that will also allow you to see if the coolant is discolored.

10-25-2006, 07:04 PM
my 1998 outback blew a head gasket but some of the symptoms were a little different.

1st. It would not overheat until you started to drive it.
2nd. The coolant was never milky because the leak was right into the cylinder so it was being blown out and burned up (the spark plugs were actually ultra clean as if being steam cleaned where the gasket was leaking)
3rd. This would cause air to leak into the system from the cylinder head which would keep the coolant from circulating properly so the top (return hose) would be hot from the coolant in the engine but the bottom hose would stay cold because the thermostat would not open due to the air in the system which would then cause the system to leak at the overflow bottle not at the head gasket itself. I replaced the thermostat and the water pump before finally gathering info from one of these blogs to find out it was a head gasket. If you have anywhere near 100k and the car has ever overheated due to loss of coolant then its likely you blew a head gasket as the mechanic told you. You can check this by having the compression checked in each cylinder. When you have bown head gasket most people think that you would always have oil in your water or water in your oil but as in my case neither was prevalent because of where the gasket was blown which was near the water jackets right next to the cylinder heads and would only leak under load. At idle it would run at normal temp for an hour but as soon as I drove it and put some load on the system it would cause the air to get into the system and screw everything up. The radiators on these cars for 1998 had a bleeder screw on the passenger side. If you don't release that you can't always get all the air out of the system and sometimes that would cause the overheating while idling. If you water bottle is filling up from the overflow then its another sign its probably the head gaskt. All those little things like dirt in the thermostat and the like are very unlikely as it would really need to be alot of dirt.

11-08-2006, 07:44 PM
A sure sign is with the radiator cap off and starting the car sends coolant into the air!
There are also tests that will reveal exhaust gasses in the coolant, yours would have tested positive for that.
Some gasket compromises on the 2.5L are so minor that only this test would reveal a problem with the gasket. Where others as I said would rocket the coolant 10-15 feet in the air!

12-04-2006, 02:00 PM
I have a 98 Outback with many of the same symptoms and was told I had a leaking head gasket. I find that if I keep refilling the radiator with coolant about every 3 days or so I can keep the temperature gauge under control. I have 2 questions: 1) the car failed the CA smog test, and I don't know whether the leak has any bearing on that or not. If not, then maybe I can fix it fairly cheaply, but if so, then it brings up the other question,
2) the car has 168,000 miles on it and I love it - but is it worth it to pay the $3-4K or so to fix the gasket ( and pass the smog test) and keep driving it, or would it be better to bite the bullet and get something else? Thanks for any input.

12-04-2006, 05:08 PM
The gasket will only get worse and then one day when you can least afford the inconvience it will strand you.
If you don't over heat it and damage the heads the repair costs are usually 1K to 1.5k I did it myself new tbelt and clutch and pressure plate for just under 500, just had the heads decked. They are GREAT cars and I dont regret spending the money. I also HATE payments.

02-05-2007, 05:57 PM
I'm checking out my Mother's 99 Outback for speedometer problems (drops out) and she recently had an overheating issue. Her regular mechanic replaced the thermostat ($160). Well, it overheated on me today. Temp gage was pegged, lower hose was cool, and upper was hot. As I gently sprayed cool water on the radiator (with the key on so the fans would spin) and it began to cool, the upper hose went into convulsions and collapsed, so did the lower. I fear a head gasket problem but need to check out the radiator and pump first. Any suggestions?

02-08-2007, 12:10 PM
btw, I've pulled the thermostat and checked it in boiling water, it opens and closes fine. I've disconnected the heater core hoses and flushed them out. I did a compression check and 1, 3, and 4 were at 200 psi after 7 good cranks while number 2 was at 188. While that one is lower than the others, it is not enough to convince me there is a problem with that particular one.......yet.
I did a combustion leak check (blue dye) and have only been able to get it to turn pale green/yellow once out of about 5 times.
It still overheats, but not badly, within about 5 miles. The wierd thing is that the gage will climb, then fall back down, rise again, fall back again. If I get back home and it's up, then by the time I get the hood open and slowly release the cap (to do a combustion leak test while it's "hot") the temp has come back down again.
I'm pretty sure it's a blown head gasket, but it must be a small one that only blows well under a good head of pressure (load). I just want to make damn sure before I tell my Mother to spend $1500 or think about getting rid of it.
Is there ANY way trapped air (in the head) can be doing this?

07-12-2008, 10:14 PM
Idid read a lo t from this known problemn of the subaru with the 2.5 lt 4 cilinder engine and I have a dout, if it happend and you did repair it this can happen again ? can hapend a second or third time. Thanks.

07-21-2008, 10:55 AM
Yes it can happen again especially if care and preventitive maintenance is ignored.
That is why a Subaru head gasket is recommended they have done what they can to mitigate this problem but the design flaw is inherent to the casting, too thin of mating surfaces.
Also Subaru makes an additive (stop leak on steriods), for the cooling system that is highly recommended for any 2.5s in that year.

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