My folks have a 99 Blazer with about 100k miles. Rode in it this evening and there wasnt any heat blowing out. Dad said it had been eating coolant lately, no visible leaks and first thoughts were ut oh....LIM gasket. DEX-cool already plugged the heater core a few years ago, we flushed and refilled with some Prestone orange stuff. Didnt pay attention to the exact name at the time.
Looks pretty straightforward, hopefully thats not it since its freezing cold here in OK and we don't have an inside place to work. However, if I do have to change it, should I use GM or Fel Pro? I know to use the Prestone LL coolant now though.
Edited to add, shoulda searched first, found an answer here. My Bad
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