2004 Subaru Outback 2.5L

So my service man tells me that there is an antifreeze leak and my head gasket needs to be replace. The engine has 139,000 miles and other than the gasket she’s cherry. Would I see water on my proverbial dipstick or oil in my radiator, or is it more subtle than that? The service man is not set up for major work but recommended either a local honest mechanic or a shady dealer…what will this run me and is it worth it?

A head gasket leak can take more than one form, including…
…oil seeping into the coolant.
…external leakage of coolant.
…coolant seeping into the oil supply and the cylinders.

The first two are not an immediate concern, but the third one is potentially very serious, and a breached head gasket can morph from versions 1 and/or 2 to the third one without warning.

First–Check your dipstick for evidence of coolant contamination (hopefully you haven’t been using straight water in the cooling system!!) of the motor oil. This will make the oil look like a chocolate milkshake, and it requires immediate attention before bearings are damaged.

Whether or not you see what I described above, look in the coolant overflow bottle for evidence of oil contamination. This will look like a dark, blurry, line at the top level of the coolant.

Also–if you get underneath the car, you can inspect for evidence of external coolant leakage.

I recommend that you do this checking a.s.a.p. and then take the car to the “local honest mechanic” for his opinion. And, bear in mind that there are two head gaskets, not one.

When the car is in the shop for head gasket replacement, that would be a very good time to have the timing belt replaced–if that has never been done. It was actually due for replacement at 105k miles, and if you have not done this, you risk VERY expensive engine damage.

Thanks for your comments…the dipstick is clean (yet!) and I do not see any scum in the overflow. I had the timing belt replaced this past summer, thank goodness…I love this car…the estimate for pulling the engine and replacing both head gaskets is on the order of $1500…does that sound about right?

That estimate sounds a bit high to me, but I suppose that I could be out of touch on repair costs.

You could always have them try retorquing the head bolts. In theory this is a process that is not necessary or needed; in practice it may well be and could solve the problem.
The price could be right but that depends on a number of factors including locale, shop hourly rates, how close they stick to the flat rate manual, parts sourcing and markup, machine shop work involving head surfacing, and so on.

This would only apply to a weepage problem with coolant or engine oil; It will not work with a head gasket breach into the combustion chamber, or chambers. It doesn’t sound like the problem with your car would fit this scenario so that’s a plus anyway.

In some cases if the coolant has been leaking for a long time it may etch the metal of the cylinder head/engine block or the head gasket and retightening the head bolts will not cure this.
Retightening the head bolts is worth a shot anyway and if you have this done then whoever does it should be able to tell you if those bolts moved some during the retightening process. Hope that helps and good luck.

Subaru actually sells a coolant conditioner that is supposed to stop small leaks and recondition gaskets. They apparently had so many head gasket failures with the early 2000 cars that they made adding this stuff to the coolant a preventative measure. According to the Subaru write-ups I’ve seen, it is said to help with that problem.

Should it not be #3 of the possibilities of failure modes VCDriver presented, you can always put that stuff in and see what happens. At $10 a shot, it is pretty cheap.

I have already added that Subaru additive and it worked for about 4 months. So today a deer runs into the side of the front driver fender, denting it, and then crawling across the hood and running away…insult to injury…and no venison…

Meanwhile I will need to replace the alloy rims soon as it is hard to fix bead leaks…

i believe your estimate for the repair may be correct. I have had this done more than once on my 2002 outback and both times (at different places) the cost was about that amount. Also, I think changing the head gaskets on these requires removing the engine with a hoist if I’m not mistaken (at least that’s whay my Haynes is telling me).

A leaky head gasket could also present with only a drop in coolant level if all you are doing is burning it +/- white smoke out the tailpipe.

Given thats’s a common problem with that vintage Subaru I’d take it to the ‘local honest mechanic’ and have him do it, ASSUMING he knows his Subies. And have it done ASAP to avoid possible engine damage.