Have a 98 outback sport. Took the engine out to do the clutch. Since it's out I plan on doing the timing belt and valve gaskets. Would it be worth it to change the head gaskets? Its at 197,000 miles but shows no signs of issues. Just dont want to tear into something that might not ever give me a problem.

 

Also, when you guys reseal the separation plate what do you normally use? There was oil everywhere. Cant tell if its also the rear main seal but would you recommend replacing that as well anyway? 

Don't touch the head gaskets or rear main unless you can confirm failures. There's a dealer upgrade stainless seperator plate that fixes the problem. A search on here should give you the part number.

 

During timing belt it's usually a good idea to do cam and crank seals - water pump is  probably due at that mileage as well. (You are doing all the idlers/tensioner as well correct? They usually fail before the belt does.)

While you are at it, go to Giant Eagle (or similar) and purchase several cans of "oven degreaser". The generic versions of Easy Off run about $2.50 a can. They contain lye, which is bar none the best oil/sludge remover and 10x better than $6 can of "engine degreaser" the auto parts stores sell.

 

Shake can then spray on block, oil pan, valve covers, k-member, etc. Let it set for 4-5 minutes. It'll foam up lightly, and will pull grease/sludge/oil up into the foam, along with loosening the nastiest of sludge. After 5 minutes, spray off with garden hose. If any heavy sludge is left, spray again and rinse when ready.

 

Your metal will look like it did when new. Can even use it on the insides of your removed valve covers, just be sure to rinse thoroughly and dry before reassembly. 

 

Do NOT use it on polished aluminum as it'll dull the finish. Rough aluminum won't matter. If you have layers and layers of sludge on the k-member, get a plastic scraper to get heaviest gunk off, then spray with the oven cleaner. 3 cans should be enough. If a little gets on rubber rack or CV boots, rinse off then wipe the boots down with a rag.

Don't touch the head gaskets or rear main unless you can confirm failures. There's a dealer upgrade stainless seperator plate that fixes the problem. A search on here should give you the part number.

 

During timing belt it's usually a good idea to do cam and crank seals - water pump is  probably due at that mileage as well. (You are doing all the idlers/tensioner as well correct? They usually fail before the belt does.)

Not so sure I agree with "Don't touch the head gaskets unless you can confirm failure." Having same motor with HGs go bad at 160K miles, and another at 185K miles is not reassuring that your HGs will last much longer. I think I would replace them, just to be on the safe side. Much easier to replace with motor out of the car. 

hmm thanks for the advice guys. Theres 3 pulleys correct? I was going to pull the timing cover and see if maybe its been serviced and see if the seals are leaking or not. I got the car for $700 with the bad clutch and havent really driven it at all. I just wanted to do some maintenance without throwing a ton of money at it. Its only had 2 previous owners so I would assume at some point its had some of this stuff addressed, hopefully. I might decided not to do heads until I deem them necessary. Pulling the motor wasnt difficult anyway. 

Not so sure I agree with "Don't touch the head gaskets unless you can confirm failure." Having same motor with HGs go bad at 160K miles, and another at 185K miles is not reassuring that your HGs will last much longer. I think I would replace them, just to be on the safe side. Much easier to replace with motor out of the car. 

 

To each their own. I've never had a set go bad under my watch. Bought a couple that already had the issues and fixed them, but I've had several with over 250k and original head gaskets.

 

Maybe if I knew it had been run hot or run with straight water over coolant I'd do it, but I've never recommended head gaskets as preventative maintenance.

That's the 2.2 engine, right? If so, I wouldn't worry about the head gaskets. If it's the 2.5, replace them.

If it has the 2.5 motor, I have heard it said that by looking at the corners of the HGs, you can tell if they have been replaced. I don't know what specifically to look for, but I bet someone on this forum can tell you.

 

As said, if it has the 2.2 motor, then don't be concerned about the HGs, they seldom give you trouble.

yea its a 2.2. Took off the timing belt cover and everything seems to have been serviced not to long ago including the cam seals. no oil anywhere. Im thinking ill just replace the separation plate, valve cover gaskets and clutch and call it a day

98 & earlier EJ22s run forever. 98 Impreza outback sport is EJ22.

 

The gaskets are the easiest Subaru head gasket to repair if it ever comes to it, I'd leave them.

 

Amazon has Gayes timing kits for cheap, all new pulleys and tensioner. It's an interference engine so if one of the pulleys fail you'll have bent valves. I'd replace timing component set and be done for another 100,000 miles (though technically I ghink Subaru calls those 60k belts in this case