Hello everyone,
I had to replace thermostats due to my originals being bad. I put OEM GM stats in it. After done, I filled the tank with the bleed screw on the housing removed. Once coolant started running out I re-installed the screw and topped off. I went and drove the truck, and noticed that whether on the highway or city driving, the temp gauge fluctuated a BUNCH. From 180-210, just back and forth. I figured their might be air in the system. I removed the bleeder bolt again in hopes some air would escape. I even let the truck run in the driveway with coolant cap off, hoping it would warm up and open the stats and burp air. It never would. I talked to a buddy of mine that works on diesels and he said to try removing the drain plug again and see if any air comes out as he's seen it get trapped there too. The truck was bone cold when I tried this first thing in the morning. When removing the screw it made a air noise and you could almost hear gurgling up through the radiator. Went and drove the truck again and temps pretty much stayed just below 210 a mark or two. Get back in town and it would fall back off to a mark or two above 180.
So...... I had already ordered another set of GM stats just incase. I tested these in a pan of water just to be sure, and they both open and closed correctly. I decided to go ahead and replace them to see if that fixed the coolant dropping off like that in city driving after out on the highway. Changed them, re filled like I described above, except this time with the reservoir cap off I ran the engine at 2500 rpms for 20 second intervals until the truck came up to 210 and the stats opened. The gauge dropped back down, and I had to add just a very slight bit of coolant.
I now go back for a test drive. The temp slowly comes just below 200ish, then dropped back off to roughly 185. I get on the highway, set the cruise at 70 and the temp comes on up and stayed right below 210 the whole time. As I'm getting off the highway and back in town, the temp dropped back off to 185-190ish.
I'm sorry for the extremely long post, but just trying to find out if this is normal temps, and to be dropping off in town like that? The outside air temp currently was 55-58*F.
Thanks in advance for any advise you all can provide.
I had to replace thermostats due to my originals being bad. I put OEM GM stats in it. After done, I filled the tank with the bleed screw on the housing removed. Once coolant started running out I re-installed the screw and topped off. I went and drove the truck, and noticed that whether on the highway or city driving, the temp gauge fluctuated a BUNCH. From 180-210, just back and forth. I figured their might be air in the system. I removed the bleeder bolt again in hopes some air would escape. I even let the truck run in the driveway with coolant cap off, hoping it would warm up and open the stats and burp air. It never would. I talked to a buddy of mine that works on diesels and he said to try removing the drain plug again and see if any air comes out as he's seen it get trapped there too. The truck was bone cold when I tried this first thing in the morning. When removing the screw it made a air noise and you could almost hear gurgling up through the radiator. Went and drove the truck again and temps pretty much stayed just below 210 a mark or two. Get back in town and it would fall back off to a mark or two above 180.
So...... I had already ordered another set of GM stats just incase. I tested these in a pan of water just to be sure, and they both open and closed correctly. I decided to go ahead and replace them to see if that fixed the coolant dropping off like that in city driving after out on the highway. Changed them, re filled like I described above, except this time with the reservoir cap off I ran the engine at 2500 rpms for 20 second intervals until the truck came up to 210 and the stats opened. The gauge dropped back down, and I had to add just a very slight bit of coolant.
I now go back for a test drive. The temp slowly comes just below 200ish, then dropped back off to roughly 185. I get on the highway, set the cruise at 70 and the temp comes on up and stayed right below 210 the whole time. As I'm getting off the highway and back in town, the temp dropped back off to 185-190ish.
I'm sorry for the extremely long post, but just trying to find out if this is normal temps, and to be dropping off in town like that? The outside air temp currently was 55-58*F.
Thanks in advance for any advise you all can provide.
