1998 Subaru Forester Head Gasket Leaking Oil

I have a 1998 Subaru Forester that is leaking oil through the head gasket. Repairs for the head gasket seem to be in the $1500-2000 range, which is at or above the value of the car. Is trying any of the head gasket sealant products such as Blue Devil worth trying? Do they have the potential to do more damage than good? I love the car, but I’m also not sure if it is worth getting if fixed or if I should be looking to sell it for parts and buy a different used car.

No additive will stop an oil leak at the head gasket. How often are you adding oil?

You must be leaking oil from the VALVE COVERS. Head gaskets would normally leak antifreeze. Maybe your head gaskets are leaking as well. I would get another opinion on this. Valve covers don’t cost $1200 to have their gaskets replaced.

I haven’t had to add oil excessively often. I check the oil before long drives (300-600 miles) which I do monthly or so, about a month ago I checked the oil and it was pretty low but after filling it then its not dropped much at all. I took the car to a dealer yesterday as I could smell and see some smoke from under the hood and there are small drips on the driveway. They said it was a head gasket leak when they looked at.

I agree with docnick that this sounds more like valve cover gaskets. Run away from this dealer and go to an independent mechanic who knows Subarus. For a car this old a dealer will milk you for all you’re worth.

Oil leaking from the right front head gasket is a common failure on these engines. At least that’s what I seem to run into. The smoke is from the oil hitting the hot exhaust pipe where it attaches to the bottom of the cylinder head.

Blue Devil or any other “head gasket sealant” is for coolant leaks, not oil leaks. Your choices are to fix it or check the oil regularly and add as needed.

The price range you were quoted is right in line with what it would cost around here.

Subaru head gaskets can certainly leak oil and/or coolant and in some cases breach the combustion chambers.

Since this is an apparent oil weepage problem instead of a combustion chamber breach, you might see if some mechanic will at least attempt to retighten the cylind head bolts as that procedure can possibly stop any oil or coolant leaks.

In theory, retightening head bolt is not recommended or required. In practice, it may certainly solve the problem.

@ok4450 If I remember those are a TTY head bolt. What do you suggest for retightening? Loosening each bolt individually and retorquing, or just tightening a few degrees beyond where it is now?

Whats the danger in driving the car right now? If I keep an eye on the oil and make sure it doesn’t get low how far is the car safe to drive? Its not overheating or drives fine currently.

A guy at work has a suburu forester, it is indeed leaking oil from a headgasket. I believe its a common problem with these engines. He is planning on dropping the engine to repair it.

There’s no danger in driving the car. Well, almost no danger. I suppose you could make the case that you could run the engine out of oil and blow it up. Not likely. You could worry that the oil will leak onto the hot exhaust pipe and flash into a fire. Also not likely. You could worry that the fumes from the oil smoking on the pipe would find their way into the passenger compartment and begin causing CO poisoning. You could worry about the leaking oil finding its way into streams and lakes and contaminating the local fish population. You could worry about winning the lottery tomorrow.

I’d make sure it isnt leaking from the oil plug. Put a piece of cardboard under the engine after you park it so it helps you pinpoint where it is coming from.
When they change oil, they are supposed to change this crush washer that’s present under the drain plug. If they didn’t do that, it will start leaking from the plug on a subie.
If that’s the cause, it is a 10 cent fix.

If the car is otherwise in good shape you might think about just paying the money to fix it. It’s still cheaper than getting a new car or a decent used car. Head gaskets are just one of those parts that eventually wear out. I see a lot of older Subarus on the road and I think it’s because they’re the kind of cars that last a long time as long as you replace things when they need to be replaced.

@asemaster, in theory the bolts are not supposed to be reused either but the Subaru factory manual I have makes no mention of replacing them. I would venture to say that most Subaru mechanics do not replace them; and speaking for myself, in most of the Subaru head gasket jobs I’ve done the bolts were reused. I’ve never had a comeback from doing this.

Preferably, what I try to do is go through the tightening procedure and allow the engine to sit all night. The next day it may be found that gasket crush overnight has relaxed the bolts and they need to be retightened before the engine is ever put back in.

Subaru started making the recommendation about no retightening head bolts sometime back in the mid 80s and not long afterwards oil leak complaints started appearing.
Just my humble 2 cents non-engineer opinion, but I think 2 things contribute to head gasket problems; loosening of the head bolts due to changes in the metal due to heat/cooling cycles, gasket crush, etc and shrinking the number of head bolts down from the prior 8 or 10 (all depending) to 6.

The same thing also happened with Nissan back in the 80s when they stated that head bolt retorques were no longer necessary. Engines soon started puking oil from around the oil feed hole in the head gasket where oil pressure was fed to the overhead cam.

@asemaster I don’t worry about winning the lottery tomorrow. I worry about NOT winning the lottery tomorrow!


I suspect that manufacturers no longer required retorquing head bolts when they started using torque to yield bolts . . .