possible blown head gasket!?!

[big_hoovie]

Yesterday, I noticed my temperature gauge fluxuating wildly - it would stay around the 'C' for a bit, then rapidly go almost to the 'H', hover there for a bit, then fairly quickly, go down to the 'O', stay there, go down further, go back up, and repeat. When I got to my destination, I popped the hood, and discovered that the coolant was boiling, and the level was down in the overflow tank. I haven't noticed any white smoke from the exhaust, but it's difficult to tell, as it's been cold enough to see your breath, lately. I checked the oil this morning, but didn't see any water deposits, but the oil(aside from needing to be changed) was normal looking(to me), if a bit on the thick side(it's been sitting all night, and again, it's been cold out).

ideas?

 

[hostile413]

i have a 96, my temp gauge did the same thing, i changed the thermostat, and temp sending unit, and it fixed my problem..have you put a new thermostat in yours?

 

[marragtop]

Put a new thermostat in. Make sure also replace the Oring gasket. You may have to buy that seperate.

 

[unclemeat]

also make sure that the flow through valve is oriented correctly, usually on top. The flow through valve is very small. There is a knotch in the block for it to fit. The manuals say twist the termostat til it seats completely, or just look for the knotch and intall the thermostat oriented properly.

 

[big_hoovie]

I definitly will try replacing the thermostat first...probably later today. couple of questions: is there a gasket between the thermostat housing and the block, or is it just sealant? do I need to use any sealant(RTV or the like) on the thermostat gasket? I assume the old thermostat won't just fall out, so I can use it to determine the proper orientation of the new thermostat, correct?

 

[unclemeat]

There is a rubber gasket that goes over the outside of the thermostat. There is not a gasket between the housing and the block. When i did mine i used a thin layer of RTV sealent, but it is not necessary. Be careful not to strip the thread, when retightning.

 

[marragtop]

Also, you'll need a 10mm socket to get the 3 bolts out of the Tstat housing. The passenger side bolt can be a real pita. I've found it's easiest to remove the serpentine belt. That way the tensioner pulley is out of the way. You don't need to take the belt off all the pulleys, just one (like the alternator).

 

[unclemeat]

Small nimble fingers really help.

 

[big_hoovie]

well, I don't intend to remove the belt, I should be able to do what I need with out doing that, but I will be removing the intake for easier access.

I appreciate all the replys, and I will keep the post updated as to wether this solves everything or not(hopefully it will)