Affecting a 1996 4Runner, 2.7 L, 2WD Here's the long version of the story.
We just got back from a year long trip overseas. The friend caring for the house and cars took the 4Runner per instructions to get coolant changed. This she did at a Jiffy Lube type place. We got home a week ago and I was looking at the 4Runner coolant overflow reservoir and saw rust in the bottom and what looked like water! WTF?! Dumped the coolant via the radiator drain petcock and there was no glycol, just what felt and looked like water and some rusty water came out near the end, too. Radiator cap was rusty inside, upper and lower hoses had a gritty rust build up. Thermostat was covered with a rusty varnish that chipped off when dry. Seems like the place didn't put in glycol with water, and that's a seperate issue with the shop, but back to the problem. Pushed the truck out onto the driveway and with hose blasted a hard stream where the thermostat fits and flushed engine out the upper hose fitting, and reversed, did the same water flush from radiator fill to drain out the lower hose and upper hose attachments in various set-ups to flush what could come out. I then stuck in a bottle of Prestone radiator cleaner (sodium citrate) and made up difference with water after changing thermostat and been driving around. Our friend said the temp never raised up ever when driving the truck around, and the same now; still at same place it's always been. I noticed that after running the upper hose is hot, lower hose cold. Upper radiator is hot, lower radiator is cold, and, the fan is always on from the moement the truck is started. Like I said, the temp gauge has never shown anything higher thgen a point just under halfway.
The questions are this: shouldn't the cooling fan come on only when the temp raises to a certain point? What's up with the bottom of the radiator and lower hose being cold and the top hose and radiator being hot? Shouldn't there be more heat showing on the temp gauge? Think the water pump is affected?
Thanks in advance