Leaky head gaskets

I went in for my 75,000 mile service for my 2004 Subaru Legacy and was told that “both head gaskets are leaking” (1 of 5) with 5 being the worst. I was told that I could wait until my 90k mile service. (But that I should keep an eye on it).

First question: Why did this happen? is there something I could’ve done (or not have done) to prevent this?

Second question: How long is it reasonable to drive around with “leaky head gaskets”?


This is not your fault. It’s the norm. Just my opinion here but I think there are a number of reasons for this chronic problems. The use of fewer head bolts, the policy of not retorquing head bolts after a 5000-1000 mile run-in period, head gasket crush (relaxation), and the metallurgical characteristics of the head bolts changing due to heating and cooling cycles.

Subaru USED to recommend head bolt retorques at 1000 miles and paid for this but that policy was discontinued a long time ago.

If they’re just weeping slightly then it should not be a problem as long as the oil and coolant levels are kept up.

What I would try is having someone retorque the head bolts. There’s a good chance this will stop the weepage.

Turbo? What boost level? If you messed with cylinder pressure or boost could cause it. I think these are torque to yield bolts. Shouldn’t need to retorque. I could be wrong.

My trusty mechanic is a Subaru fan,He works at the dealer and repairs head gaskets on subaru’s all the time,usually(75K-125K)I guess the early 2.5 just fail with time. But he says the newer motors are better, but not changing the coolant and or using a different brand of coolant to top up seems to add to the failure rate.who really knows??
P.S I do not own a Subaru.

Thanks! I will talk to my mechanic about re-torquing the the head bolts

No turbo. It’s just a regular car. I use it to drive to and from work.

I guess there will often be some problem with any new system. I didn’t know that I was buying a new design. I don’t manage the coolant myself, I let the oil changers (different ones) top it off. Maybe that’s my problem. I have had the coolant replaced at 30k and 60k according to the maintenance schedule. I will ask my mechanic about the brand(s) of coolant. Thanks