Not heating up (Page 1/1) FX JAN 18, 01:06 PM This is not Fiero related, but GM. I know there are a lot of guys on here with good general automotive knowledge. Some of you may even have run into this problem with a Chevy 5.3 engine. It's in a 2003 C1500 Suburban. The problem is, it's not warming up to operating temp while idling for 1/2 hour. Temp gauge barely moves to about 100 degrees ( gauge is accurate), normal op temp is 210. Really cold up here in Buffalo NY. It takes a good half hour to get up to temp while driving. Has new rad. water pump thermostat (stock 186 degrees), and coolant...Any ideas? I have exhausted my net searching on the problem, and came up with nothing. I really could use some help. If nobody wants to reply to this because it's not Fiero related, I'll understand... Tony Kania JAN 18, 01:22 PM I would venture to say that your thermostat, even though it is new, failed. Only going by your written assessment. Check for coolant level. Is there a bubble in the system after the new parts? FX JAN 18, 01:41 PM Coolant level is fine, and new. I've burped the system of any air. I'd like to rule out the thermostat because the one I took out tested good. With the new one in, it is acting the same. I even tested the fan clutch as being okay, not stuck on...