Water in the bolt holes

[Unregistered]

I have a A4 whose serial number puts it as being manufactured about 77 or 78. I began installing a new thermostat today and did not drain the engine before removal of the old thermostat. I noticed water in the bolt holes. I tried removing the water with towels and found they refilled with water until I drained the engine. Would this indicate that the head now needs to be removed and a new head gasket be put in place?

[Don Moyer]

All of the head studs (including those in the thermostat housing) enter into the water jacket, so there is nothing to worry about in terms of the water appearing in the "bolt" holes. I am concerned, however, over your referring to the thermostat housing stud locations as "bolt holes". If someone installed bolts into the holes that were originally intended to be used with studs, you should definitely replace the bolts with proper thermostat housing studs. Torquing bolts into the holes in the block that were intended to be used with studs puts you at great risk of damaging the threads in the block.

One of the reasons that bolts were sometimes (ill advisedly) used to secure thermostat housings in past years was to accommodate the additional thickness of a spacer that may have been installed between the thermostat housing and the head to accommodate a particular aftermarket thermostat. If this is your situation, you can replace the bolts with standard manifold studs, which are approximately 1/4" longer than standard thermostat housing studs. If your thermostat does not require the use of a spacer, you can replace the bolts with standard thermostat housing studs.

If you really meant to say "stud hole" and not "bolt hole", you can forget all of the above, except for the fact that there is nothing wrong with water coming out of the hole.

Don