OK, I got really weak heat, but it is sufficient to save my life. Not what it used to be, and my expectations with my truck...and other vehicles with which I have experienced. My last post back in Sept 2022 thought it might be the blend door actuator....but it is fine. Last summer I did what I always thought was proper flush & fill. Prestone Flush & Clean. Reverse flush the heater core. Ran water through until it was clean. New Prestone 50/50 install using my Lisle Spill Proof Funnel (must have). All OK, but noticed heat still weak, so rather than flush out my new coolant, I again reverse flushed heater core with compressed air......added 1/2 cup of CLR and let it be for 45 minutes. More compressed air followed by clean distilled water. Reassembled all connections. Brought out the Lisle funnel and topped off with fresh 50/50. This time got a bit more aggressive with air purge....squeezing the radiator hoses to really push through the coolant.....Well that is when I noticed various sizes of "black gook" floating up into the funnel. I have concluded that there is some serious crap in my system....likely in the radiator (I drive this beauty aprox. 2000 miles per year). No other issues! No leaks, no overheating....all else is fine.

Looks like I am going to waste the new coolant. I intend to initiate "intensive coolant system care. Looking for best 100% clean out procedures & products. And especially how to care for a low mileage keeper. Only 133K .

Any suggestions for the best job & method possible? Thanks in advance.

Louis

 

Sounds like you have done what you can do. The old radiator guy in town, Courtney (A Good Place to Take a Leak), tried to tell me to get it up to operating temperature, then yank the lower radiator hose and let it drain. I'm too much of a pu$$y to try it, though. LOL

 

Since your radiator is in good condition you could always remove it and have it hot tanked. It wouldn't cost as much as getting it re-cored and it would get rid of all the goop.