What are the signs of a waterpump failing? I have an intermittent problem of my temp. shooting up to about 210 during intial warm up (driving only) and when I get on the throttle it will creep right back down to 190 where it will stay. I have already changed the thermostat twice (185 degree) I have a 4 core radiator with flex fan and shroud, fluid is fresh and clean. All this is on a fairly stock 350/300. I believe the waterpump is original. Seems as though it needs that extra boost to get the water pumping into the motor.
Any suggestions? or is this just a fact of life?

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Bob
Email: bob70@chevelles.com
My Chevelle: members.aol.com/rdcnh/70index.html (http://members.aol.com/rdcnh/70index.html)
Team Chevelle Gold Member #169
New England Chevelle & El Camino Assoc. #085

Usually water pumps fail in the bearings or the seals and it is pretty easy to see what the problem is. However, your problem may be that the pupm impeller is loose on the shaft and works intermittently. One way to check this (though not very accurate) is to let the engine warm up until the thermostat is open and rev the engine while looking into the radiator tank. You should see a surge in the flow of water. This works best with a top tank type of radiator. Alternately, you could remove the upper hose and see if it pumps well after the thermostat opens. Removing the pump and trying to move the impeller would be the most telling. And (finally) you should check for a collapsed hose that will not flow until there is enough heat to really expand the water. might try opening the cap to let in air before you start in the morning and see if this will change the heat up cycle.

If you check all the things suggested above and nothing helps, try looking at your thermostat. It might be sticking. The good thing about it is that it's a cheap fix!

-----Jerry----

I agree. Check the thermostat. Put it in a pan of water and heat it on the stove. If it doesn't open, get a new one. Simple, cheap fix! http://www.chevelles.com/forum/smile.gif