2008 ford ranger v6 4.0L 4x4, 171,000km.

About 15,000km ago, I replaced thermostat and flushed out the coolant system. Refilled with Ford coolant concentrate with distilled water.

Last winter it ran ok..... But I've noticed a gradual decline in temperature since I first bought it.

Now, engine temperature sits just below middle of the gauge, and I can't keep my feet warm. Blend door works, and it does blow warm air, but not as hot as I think it should.

Any ideas?

Ps, it's -20c outside, so I've given up on garden hose flushing the heater core 🙄

 

are you running the fan on full blast or on a lower speed? If its really cold, then the faster you run the fan it overpowers the heater core

 

Full throttle at start-up. Then I dial it down a bit. I guess to summarize: I can't get the cabin warm enough as I could in previous years. I either have to defrost the windshield when Im enroute, flip it to forward vent/floor (or just floor)to thaw my feet, or full vent forward to warm up.

You got me thinking though. Perhaps I have a poorly fitted door seal or window seal or some pain in the butt to fix in the winter.😤

 

in the spring time or when it warms up enough, i would try to do a full flush of the coolant system including the heater core

 

I absolutely HATE it when people argue with me about something that I'm obviously an expert in, and they are clueless. In this case, I'm the clueless one. I'm at a complete loss.

I did the coolant flush with the thermostat replacement less than 2 years ago. Is it possible to have the coolant degrade that much that quickly?

 

its possible that the flush caused some debris to break loose and get stuck in the passages.

Next time you drive it, check the temperature of the heater hoses, if you feel one that is drastically different, you found your problem

From the info you have given, it seems that your truck is warming up properly. IMO its a circulation issue

 

You might try switching the heater hose positions: does a back flush as it circulates: if there’s a clog that could loosen it, perhaps?!!?
Judgejohnmd

 

Interesting thought. I woke up late last night to let dog pee, and I was wondering if it isn't clogged per se, but coated with scale. I guess that's a clog as well.

I was pretty thorough with my flush though. One never knows though.