Low heat from heater/defroster

First, if the heat isn't as hot, make sure you bleed all air out of the system. You may have an air blockage. Next, is the engine warming up to normal operating temp? Finally, the compressor should cycle a little longer than 5 seconds. Either the cycle switch is bad or it is low on freon.

Let me know.
Joe

Have added freon and have been flushing the system. Air seems to be hotter now. Mechanic thinks that the heater core is clogged with debris.

Son took car on freeway for about an hour or so and reported that the temperature gauge goes to hot, like it is overheating, but when he turns on the heater it drops. What could be causing this?

Thank you for your reply and assistance.

Dave

Actually, that tells me the heater core is good and NOT clogged. The heater core is nothing more than a small radiator. When you turn the heat on, hot coolant from the engine runs through it. WHen you turn the fan on, it blows through the heater core and blows hot air into the vehicle. If the temp drops when the heater is turned on, that tells me coolant is flowing through the heater core, cooling off, and then helping cool the engine.

At this point, here is what I suggest. Since the temp gauge shows that the engine gets hot then cools, that tells me a couple possible things. First, it sounds like an air pocket in the cooling system that is slowing coolant flow. Have them try to rebleed the system. Next, if that doesn't help, have them replace the thermostat. Keep in mind, the old radiator would not have had the same flow as the new one. Consequently, the temp would have run hotter and the heat would have been hotter. Now, how can that be fixed? The thermostat may not be working properly. So, after trying to bleed the system, if it doesn't help, have the thermostat replaced to see if that levels out the heating up issue. While the thermostat is out, have the mechanic flush the engine block and both forward and reverse flush the heater core. NOTE: It is important that he reverse flushes it too. After all of that, if the engine still overheats and you get poor heat in the vehicle, my next guess is you have a bad headgasket. ONE LAST THING... before they start into expensive repairs such as a headgasket, have them replace the temp sending unit to make sure it isn't sending a false signal to the temp gauge in the vehicle. The engine may not be overheating at all, but rather you are getting a bad reading in the vehicle.

Let me know how things work out for you and if you have other questions.

Joe

Thank you for all your help. Mechanic replaced thermostat. Stated that seemed to work for about an hour and a half, then the gauge went to the red line. Mechanic power flushed, both forward and reverse today. Stated that the temp gauge goes to the middle then stays there. Let car rest for about half an hour, then tested again and said that the heater wasn't putting out a lot of hot air again. Mechanic says that he is not confident that the overheating wont happen again - wants it to be consistent.

Does not feel that it is the temp send unit becuase he told me that he scanned it using an infrared scope or something like that and the water was hot.

He also said that he does not think it is a headgasket either because there are no other signs of that. I can't remember what he told me one would see if there was a busted headgasket.

He has contacted a friend who works in a Ford Dealer regarding this issue and discovered that the older Escapes and Ford Taurus' were notorious for this. Great. Friend is going to send my mechanic some information that they (Ford) may have to resolve this.

Frustrating to say the least. Thanks for all the help.

Dave

Glad to help. Let us know if you have questions in the future.

Joe

Finally got the car back. I was driving it home and the gauge was in the middle, then I felt a 'thump' in the engine and the gauge started to move up to hot. It hit hot as I stopped at a red light. Then moved back down again. When I started up, it went up again, and I tried turning on the heater to see if that would bring it down - as it had before. It didn't. The engine started to struggle abit, so I pulled over and parked it. I returned after a couple of hours, and drove it home the rest of the way without any issues - but I didn't have to go far at that point. Taking it to the dealer in the morning, any ideas?

Thank you