Subaru Head Gasket - what else is new.... :)



So, I have a 2002 Subaru Outback.

A couple years ago I started smelling an odor from the engine. I brought it to the dealer and they said the gaskets were leaking (or valves- something like that - i’m not a mechanic).

I brought it to another mechanic for a second opinion and they said nothing was leaking. So I continued to drive it.

In the meantime, I’m noticing that the car would hiccup (slow down and then go faster) on occasion. Eventually it just stopped on the freeway and coasted to a stop.

A mechanic replaced the valves, timing belt, etc. (for only $890 - great deal). The odor went away and the hiccupping stopped.

So, fast forward two years. I’m feeling the same hiccuping begin to occur, the smell is back and the car drives rough.

Brought it to the dealer and they said they didn’t smell anything and just change the spark plug wires.

Brought it to another mechanic for a second opinion. He said there was a small leak in the head gasket but it is nothing to worry about. He agreed with changing the spark plugs which he did.

I indicated to this dealer that the scenario feels very familiar to the first head gasket failing and I’m afraid if I ignore the leaking head gasket that the car will eventually stall out on the freeway again.

He indicated to me that he felt the first time this happened, it was not due to the leaking head gasket but that the timing belt broke on the freeway and that is what ruined the valves. But what confuses me is that the hiccupping and the smell went away after the new head gasket.

Since the most recent repair of the wires, the car runs a bit smoother but not all the way.

Next morning after the new wires are installed, the engines runs incredibly rough and the check engine light goes on. Diagnostics indicated it was a cylinder - he tightened the wires and everything was fine.

Two days later, the engine light goes on again but engine is not really rough. Diagnostics indicate its the catalytic converter (which was replaced under warranty about 5 years go).

All in all, I’d say that the engine is still somewhat rough but better than before the wires. Not enough time has passed to see if the hicupping is still happening - it was only happening on occasion.

So, I need to ask those who know about this kind of thing:

1 - was the first head gasket which needed to be replaced due to (a) a broken timing belt (which was had been replaced and practically new) or (b) the leak in the gasket/valve.

2 - Is the current leak in the head gasket something that needs to be fixed?

3 - Is this head gasket problem gone in the 2009 and 2010 models or does Subaru plan on living with this legacy (get it?) forever?


thank for any feedback which will help me to understand all this and make a decision!

  1. The head gasket problem appears to be fully corrected in 2005 - present Subaru vehicles.

I am personally amazed people consider another after having some expensive problems with them.


You have presented a tough one to figure out as there is so much missing information and a few things that sound odd. Just a few of those oddities include:

A timing belt and bent valves are not going to cause hiccupping and then improvement.
A timing belt job and valve replacement for under 900 bucks??? (for one head maybe?)
Tighten the wires???

Often head gaskets leak externally but in your case maybe one was leaking coolant into one of the engine cylinders and this caused a hydrolock which in turn snapped the timing belt. (theory)

A properly repaired head gasket job really should last the rest of the life of the car unless the engine suffers some overheating.
Now whether this job was done properly I would have no idea because there’s a head gasket job and a head gasket job if you get my drift.

The converter could have been damaged by coolant leaking into the combustion chambers past a leaking head gasket so you can see where this is feasible.

I would recommend getting this car scanned for any codes that may be present. AutoZone, Checkers, etc. will do this for you free and it only takes a few minutes. Post any results back here.
Something else that should be ruled out is valve lash, which should have been set during the head gasket job. Tight lash can cause an engine hiccup and it can also be a hit and miss thing, depending. (won’t get into that at the moment)

Diagnosing a head gasket fault is not a guessing game. Compression test, vacuum test, hydrocarbon test, cooling system pressure test are all things that can be done to make double sure of this problem.

I hope some of these pretty much random comments help and wished I could be more precise but there’s just too many unknowns and from your post I detect some guessing going on by the mechanics.


Based on the evidence you’ve presented, I’d say that perhaps you had a small head gasket leak originally. Then you had a timing belt break or slip while you were on the freeway, causing part of the valve train to self-destruct. When the mechanic replaced the valves (or the head), he put on a new head gasket, which cured your head gasket problem, which was unrelated to the timing belt issue.

When you more recently got a tune up and it was running very rough, it sounds like they botched something–a wire came off, perhaps they got the firing order wrong (wrong wires on wrong cylinders), hard to say.

It does sound like the car was repaired properly in 2005, but possibly the problem has returned. Since you do not know much about cars, I’d suggest taking it to another mechanic for a second opinion if the head gasket is leaking. It may be possible to live with a small leak depending on where the head gasket is leaking. But if the leak is causing coolant to mix with your engine oil, this will quickly destroy your engine. So please get a second opinion, and if the gasket needs to be replaced, you’re best off doing it soon if you plan on keeping the vehicle.


Only skilled mechanics should own and drive Subaru’s.

Enter the word “Subaru” in this forums search window…


Thank you oblivion for your post. It really put everything into perspective and I understand it all more clearly now.

A few people have asked why someone would continue to purchase Subarus. I can not speak for others, but for me, it has been fantastic in the snow. I live in a snow belt and sometimes have to go up my driveway with a foot of snow (or more) on it (on a slight uphill). My Subaru does it with no problem. It handles beautifully and is fun to drive. I guess I’ll have to see if in actuality I keep having head gasket problems.


"Only skilled mechanics should own and drive Subaru’s.

Enter the word “Subaru” in this forums search window…"

I’ve know many people who never had any problems with their Subarus. I think this forum just has a disproportionate number of Suburu, Volvo, Audi, and Prius drivers compared to all other makes.