I have a 2002 Subaru Outback. According to the mechanic, it is a leaking head gasket and will cost about $1500 to repair. The car already has 167,000 on it. I just don’t have the money for the repair. Is there any sort of sealant that could be added to the oil to help with this issue? I’m not exactly “mechanically inclined” - but I think I can handle adding something to the oil. I just don’t know what product to use. I’d like to try to get it to last for a few more months, until I can be in a position to by myself another car.
Nope. There is a sealant you can add to the cooling system in the event of a coolant leak at the head gasket, but for an oil leak on these engines gasket replacement is the only option. This is a common issue on these engines and a relatively routine repair. $1500 is a reasonable price for this assuming it includes a new timing belt and water pump and oil pan gasket. If the rest of the car is in good condition why not repair it and get a few more/several years out of the car? Just the sales tax on a new car will be more than the $1500 to repair this one.
If you can find someone willing to do it you can try having the head bolts retightened. You may be told this cannot be done or is not necessary but it is a viable alternative that may work.
Good advice from both @asemaster and @ok4450. If you are going to keep the car try to set some money aside to get the repairs done later on. Place a pan under the car to catch the oil drips at home. If you get the work done make sure the other normal replacement things are done also at that time.