Blown Head Gasket

Yes. Definate HGF.

Pull the plugs first thing in the morning and with a torch look down into the cylinders- am certain you will see coolant sat ontop of one piston.

Tim..

That seal on the water pump is very common and I would certainly try replacing that before doing a head gasket. If you're having someone else do the work then it may be better to have a leakdown test done. Replacing the head gasket isn't something I'd do for fun, but it's not too bad either if you have a well lighted and heated shop and all the right tools on hand. Last one I did took a long evening.

Yes, make sure you correctly diagnose the problem before undertaking repairs.

The last thing you want is to replace the O-ring, only to find out that wasn't the problem.

Well you should replace the O-ring either way, but you do want to diagnose the head gasket before pulling the head off.

Yes, of course the O-ring must be replaced in either event, but there is no sense misdiagnosing the problem, only to find you are replacing the O-ring twice.

You don't want to run a car for long with a bad head gasket.

Among other things, water can be very, very bad for bearings, as it hasn't the lubricating properties of motor oil.

Running an engine with a blown gasket can cause a depletion of coolant, which will cause overheating which can warp the cylinder head and cause the engine to sieze.

And a head gasket problem can get very much worse very quickly. If you pull the plugs and compare them, you should see a difference if there's a problem.

I agree, although I think that I would try retightening the water pump bolts first to see if that makes a difference. I can't see the problem with determining if the leak is coming from the pump mounting point of the cylinder head. Seems to me that that would be a fairly simple observation, so I don't know what the problem is there. I can't remember when Volvo went to the non-retorqueable (Is that a word?) cylinder head bolts but I think that I'd try re torqueing them to see if that makes a difference. If your engine has the one torque type of bolts, then don't go there, but I'd definitely look at the pump first.

My experience with the top seal on the water pump is that if disturbed it will leak, whether it did before or not. Since the bolts don't actually snug the pump against the head it's probably a losing proposition.

Mike

I use a thin skim of blue RTV on the top "O" ring and also on the smaller "O" ring on the end of the water pipe.

That works well on a new ring, but if it is leaking now the ring has deteriorated to the point it will not seal no matter what. Believe me, I've tried 8^P

Mike

I agree, I wouldn't think it realistically possible to reseal the failed "O" ring on top of the water pump.

It seems almost a "black art" to make them seal correctly.

While you must put upward pressure on the pump while tightening the bolts, if you put on too much, it can leak (I know, it happened to me).

I always take a wire brush to the head surface to prep it.