MNorton
Newbie
I purchased a 1994 GMC Sierra C1500. The engine has been replace with a rebuilt 350 from a 1999 suburban. Also the throttle body injection has been replaced with an Edelbrock carburetor. I am in the process of trying to get all of the cluster gauges to work. When I hooked up the temperature gauge it fluctuates just like a sticking thermostat. Warms up but goes to like 220 on the gauge before it seems to open and cools down to 140 or so. Then it just repeats over and over. I replaced the thermostat with a 195 and the upper radiator hose due to the alternator had nicked it. I thought maybe there was an air bubble and there still might be. I do think the head gasket is ok, there is no water in the oil. I thought maybe the gauge was bad so I added an aftermarket water temp gauge and it pretty much tracks the cluster gauge. What do I look at next? Possible bad water pump?