First things first, I own a 98 2door 4x4, ZR2. Thanks in advance for any help/advice. My problem: I can smell antifreeze when driving and there isn't any heat when I turn it on. I am preparing to replace the core this weekend but if there are any other things I can check please let me know. Also, when driving more specifically when accelerating there is a buzzing noise from behind the dash. Kind of sounds like a bad bearing. Since I'll have the dash apart seems like a good time to go after this issue also. Thanks again for any posts.

 

The buzzing behind the dash may be caused by the cruise and/or throttle cables resting on the PCV valve tube that runs from the intake manifold to the driver side valve cover. Worth checking out.

 

Wow! Swartlkk!! You just fixed a mystery noise in my Blazer that has been bothering me for a few years!! (The buzzing at idle in gear with the A/C on). Just put an upper radiator hose on, and wife noticed that the mystery noise got much worse. Knew it had to be something around the intake ducting that I took off and put back on. Apparently mis-rounted the throttle cable when I replaced the engine way back when.

 

Oldie, but goodie! Catches quite a few!

 

The ability to search past posts for answers is one example where Facebook is completely inferior to forums like this. Once that post on Facebook is a few days old, it is pretty much lost forever. Sad, isn't it! Why I don't waste my time with Facebook automotive groups.