2001 Ford Explorer - No heat

ewr30a · 11-07-2009, 02:06 PM

Hello,

I have a 2001 Ford Explorer XLT 4.0 6Cyl with 161k miles. At the moment, I don't have any hot air blowing out the heaters. In addition, the hoses to the heater core do not appear to get hot as I heard they should, or at least one should. I changed the thermostat thinking that was the issue with no success. Cold air still blows out instead of heat. During the summer I also had no AC but am not sure if that's related. After replacing thermostat I placed a water hose and ran water through the core and it did not appear blocked as it flushed out the existing coolant. Again, no matter how long the car is running the two hoses do not get hot but if I open the release valve on top (circular cap) coolant starts to shoot out. Car temp displays cold when cold and normal temp when car warms up about 15 minutes or so. Just no heat. Any suggestions. No fluid under dash to suggest a bad heater core. Any help would be greatly appreciated.

ewr30a · 11-07-2009, 05:37 PM

just had someone take a look at the truck and they believe the thermostat I replaced it with is no good. with heat detector aimed at hoses car is only getting up to around 140 degrees. Neither hose to firewall gets hot. said it's either the thermostat or water pump??? any input would be helpful. thank you

BroncoJoe19 · 11-07-2009, 05:57 PM

Its pretty cool that you have that tool to use in your troubleshooting.

You didin't give us enough information for us to be able to help very much.

How about I give you some info and see if you can figure out what is going on?

Your thermostat should allow the engine to heat up to about 185 before it passes water to the top hose of the radiator, so what temp should the top hose of the radiator be when the engine is hot?

The coolent becomes cooler as it travels through the radiator, therefore..
The lower hose should be cooler, the cooling fans should come on as needed.

The temp of the heater core hoses should be near the temp of the top hose to the radiator.

ewr30a · 11-08-2009, 11:54 AM

Thanks for your reply. New, so my apologies for not giving more info. Neither of the hoses were higher than 140. I would think if the engine passes water to the radiator at 185 the hose should at leat mirror that temperature if not a little less but not 40 degrees less. Also, the top hose to the core was about the same temperature which even to the touch was not hot compared to cars who's heat was working. Even once the car is running it doesn't get hot enough that removing the cap from the radiator appears to be a threat. What are the chances of me buying a bad thermostat from Auto Zone?? Don't want to continue to do the same thing expecting a different result but it was his best recommendation other than replacing the water pump.

BroncoJoe19 · 11-09-2009, 07:42 AM

Sounds like a thermostat that is opening too soon.

You can test it by throwing it into a can of water, heat the water, and observe at what temp the thermostat opens.

wwest · 11-09-2009, 11:17 AM

You have a vapor lock, air bubble, trapped in the heater core or to/from hoses.