How do you pin point which side of the engine has a blown head gasket?

Question

I have a blown head gasket that is only blown to the radiator, when you start it, the water sqirts out the top

no water in the oil, just a little water coming out the tailpipe, not enough to cause smoke.

How do I figure out which side of the engine has the blown head gasket, I don't want to have to do both sides.

Do I have to pull out the spark plugs?

subaru 2.5 eng

Answer 1

Remove the spark plugs and do a compression test on all the cylinders. The one with the bad gasket will be low, as some of the compression is being lost into the water jacket. You might have to remove the whole engine, anyway - I'm not sure how much room you have to work on the engine, since a boxer (horisontally-opposed) engine has the heads so low.

Answer 2

A compression test and yes, to do this the plugs have to come out.
You never said if its a turbo cause it might be the intercooler.
Get a mobile mechanic to look at it for you. Its free and then youll definetely know what the problem is.

Answer 3

You might as well do both sides because your going to have to pull the motor to do this anyway, don't want the same problem a few weeks later.

Answer 4

well thats one way to find out pull spark plug out the one thats the cleanest that will be that side but if one already fail just do them both .do a value job they are already out dont be cheap it will hurt your pocket later on

Answer 5

pull a plug out on each side and see what side the plug looks wet .

Answer 6

look and see which side water is blowing out

Answer 7

need to do both side s

Answer 8

Do a compresion test