temp gauge moves a lot

[93rev2sev]

I seem to be "consuming" coolant, too. Although, I think it's my water pump...leaking from the weep hole onto the hot block and down onto the exhaust. Whatever dosent steam off of the engine is being burned up on the cat. It only leaks under pressure, so I never see a puddle.

How old is your water pump? If you suspect it's the pump (or if you want to diagnose the leak at all) get a coolant system pressure tester. Pressurize the system and see how long it takes to lose pressure. Once it loses pressure(even if it takes an hour), repressurize it. Do that 4 or 5 times on a cold engine and you will see where it's coming from.

Make sure you will be able to trace the leak. Start with clean cardboard under the front of the car. You wll have a fresh coolant trail to follow and you will probably be able to see the dripping.

Another common spot for "invisible" leaks are the heater hoses. These are rubber and steel hoses on the drivers side, behind and under the throttle body. Look at where the steel tube turns into to rubber hose.

 

[rubydist]

My red 94 had a loose clamp on the upper hose at the engine end - would leak just a little, and the engine heat would evaporate it, so it never dripped. I only found it because I opened the hood w/ a hot engine and saw the little wet spot on the top of the engine. Tightening the clamp solved the loss of coolant problem.

 

[dwarf]

So where do I get/rent this pressure testers and how does it work?

 

[93rev2sev]

Well, I have a stant pressure tester. They look like a stubby bicycle pump with a radiator cap on them. Take your radiator cap with you and make sure theres a fitting to match it.

Put the cap on your radiator and start pumping. Pressure will go up quite fast if the system is full and the hoses are new. Don't take it over 15LBS of pressure.

Go slow once pressure starts to build. Don't pump hard enough to make the pressure spike over 16 lbs. If it does, you could blow out an otherwise good seal. The trick is to simulate pressure going up due to the engine warming up.