No more than 12 months ago I had a radiator flush performed on my 2001 Blazer. Recently the heat blows cold and the engine temp runs up past 210 degrees. after running the truck up to 55 mph the temp will drop down to normal and I will then have heat in my truck. Yesterday when I drove it, the temp never dropped and actually increased up to the point of the watch gauge light coming on. Since I have parked it until I can get whatever problem I am having fixed. Did notice a slight smell of radiator fluid from outside of the truck. And when I lifted the hood, all the coolant was empty in the reservoir. What gives???? Just had my radiator taken care of last year. Any tips would be greatly appreciated. Also noticed a small drip under the front of the truck on the drivers side. Thanks for any advice

 

Leaky lower intake manifold gaskets are a known problem on this engine. When they initially start leaking, the first sign is an empty reservoir, and no evidence of a leak. They usually sprout leaks at the front and rear corners of the lower intake manifold: Under/behind the alternator and under/behind the AC compressor, and at both rear corners. Usually difficult to detect without being a contortionist and using a mirror. Pressurizing the cooling system sometimes helps. The gaskets can also leak internally allowing coolant to contaminate the oil. Best to have it repaired ASAP, along with an oil & filter change, before it damages the engine.