My truck took a long time to get warmed up and the temp gauge would not go past the notch by the "C" which was about 1/4 from the bottom. So I thoughtthe thermostatwas stuck open. I replaced it and the old one was bad. Anyway my question is this. I got it out today after I changed it. It got warmed up in no time and I let it run around the house for about 5-10 minutes while I loaded my truck up with some junk to take off. Not more than 20 pounds of junk. Anyway it got hot at first and I figure it was due to ideling. It when up the gauge maybe 80 %, it was just below the first line of the "H" side. Then after I got it on the road it stayed between 60%-70% of the gauge. In other words just a little above the half way mark. It is a 4 cylinderwith a webber carb 91 extra cab.The temp today was between 55-60 F. I am thinking this is normal. I just don't want to get it out on a warmer dayand have it to get hot.So does the temp sound right?

 

it sounds like that you have an air lock in the cooling system, you can releave this by taking the hose off of the themostat ( when its cold of course and hold the themostat open to purge the air out of the system and you can fill the system properly, I say this because i had this problem on mine and the air causes it to overheat and than when you can get the fluid moving it cools out, you need to get the air out or you will fry your thermostat or in a rare case crack the block if you have the air block freeze in a cooling passage.

 

I tried that. I pulled the hose off the top and pushed the thermostat open with my finger. I opened a couple of times the best I could. I think it helped some. For the most part it stays at 50-60% but it does have times when it hits 80%. I think I will try that again and use something else toopen it. I may even try to pour some antifreeze in it. Do I need to start itsome to let it force the air out?
Thanks for the reply.

 

You can run it a few times, and after it cools, open the radiator cap and see if there's space to add more coolant. I just replacedthe radiator on mine (running too hot on highways, CarQuest), and it took about three "fill checks" to get it all coolant and no air. Now it goes about 1/4 inch into the zone, and we're still in the 90s here, and still using the AC (1988 Cab Plus). Also, you can always in a pinch turn on your heat on high and help cool the engine that way.