One post down below prompted me to post this. First let me say that I never replaced the headgasket on the car,.....ANY car. However,....I've been racing Superbikes when I was much younger, and I did a fair share of head gasket replacements on inline fours, AND on V4s.

There are several reasons why headgasket fails, but most common one is overheating. So what happens? As the block overheats above the normal temperature, the block expands (along with the studs), and when it cools down again (to the normal operating temp) the head doesn't fit as tight to the block as before. One can attempt to retorque the head, and sometimes it works. If the head is not retorqued, the pressure from the coolant is greater than the seal created by crushing the headgasket to the original torque, can handle. Makes sense? So, the coolant finds the weakest spot to leak into the cylinders.

It's very well documented on the web, that in the case of V configured engines, one HAS TO replace BOTH headgaskets at the same time. There are no shortcuts. If one bank started leaking (and it's fixed), the other one is in the same state of weakness as the one that was replaced. It's just a matter of time (usually VERY short time) before the one that's left alone, starts leaking.

So if you are attempting to change the headgasket, do them both, and you'll be glad you did. Basically,....one is looking to rebuild the whole top end in this situation (resurface the heads, lap the valves, change seats and shims,....the whole thing). The best way to do it, is to pull the motor, and do it on the stand. It's a lot of work, but not a brain surgery. All the info is available on the web, and if one goes slow (and documenting every step) it can be done in a day or two.

 

Sage advice.