I don't drive the Jeep much in the winter because of the salt they spread on the roads here. Last month the wife and I decided to take a drive out to the west desert, along the old Pony Express Trail, to see if we could spot any wild horses. That's when we discovered the heater was not working. Have you ever taken your sweetheart on a road trip with the heater not working? No bueno.
I checked the for the usual problems. Air pocket? Nope. Bad thermostat? Nope. Water pump failure? Nope. When I touched them, both heater hoses were so hot that I could only hold my hand on them for about a second. I unhooked both hoses and ran water through the core, no problem there. Using an air hose, I could blow through with no problem as well. All the blend doors were working normally, the heater fan worked on all speeds and I could feel the end of the temp blend door axle and it was rotating when I turned from hot to cold and back.
Today I bit the bullet and decided to remove the new heater core. I had purchased one from Napa, it says Spectra on the sticker. I used a small flashlight to look inside it and could see something that looked like it should not be there. My curiosity made me open the thing up and here is what I found inside.
Luckily, I kept the old heater core, (the one that was working just fine). When I looked inside the old one. I can see that there are no plastic inserts in the tubes. I do not know why Spectra would put these inserts in the tubes, but it apparently affects the efficiency of the heater core. I plan on reinstalling the old heater core tomorrow.
I included a gratuitous photo of the wild horses, it was a herd of about 50.
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