93 xlt running cold

[mchammer]

my 93 (4.0L OHV) started runnig cold two years ago. I replaced the stat with an oem ,properly installed and bled.no help. Went to the dealer , payed some $ ,they did exactly the same thing. Still no heat. We get minus 35-40 degrees during the winter (thats C or F ) almost the same. The vehicle is almost undrivable. The temp guage slowly rises to the 'N' and then quickly drops to stone cold. A cooling system pressure check showed no leaks. Oil is clear. I changed the clutch fan. No help. The rad hoses feel warm and the temp gauge will creep up to the 'N' while sitting and idling , but as soon as you get air flow through the rad the heat is gone. Now I have the rad 80% covered for the winter but this only helps a little. Contacted the manufacturer for possible solution but never had a reply. Love the explorer , its a big improvement over the blazer just wish we could drive it all year. This XLT has 216k on it and otherwise runs great! Any ideas or suggestions would be greatly appreciated. Thanks

 

[toad]

Hey mchammer welcome to the board, sounds like you got most things covered , Im stumped, thinking heater core plugged maybe , should be like a 190deg. or so thermostat . Not much help I know hope someone has the answer. Good luck.

 

[MSTNGGUY88]

One suggestion is the motor is getting wore out. Once your motor starts becoming loose it will take alot more time to warm that bad boy up. We had a worn out 5.0 in a nissan project truck that in 50 degree weather would never heat up to 160. So maybe that could be the prob. Run a compression check on the motor and that should tell you if that's the problem.you should run no more than 10-15 psi between cylinders. My freshly built 5.0 runs a 180 compression on all cylinders and the worn out one from the nissan run a 95-115. Both motors even have a compression ratio of 9:1. Let me know if this helps and good luck.

 

[toad]

Hey mchammer I checked mine out on the way home from work yesterday morning, it was about -4 or so out and the gauge never got above the "o" in normal for the whole trip (45 klicks or so) but I have lots of heat,just some info for ya.