Subarumor Posted January 19, 2015 Share Posted January 19, 2015 I have a 93 Loyale wagon, 190k miles, 5speed, a/c, heater . . . did I say "heater"? Heater exists physically, but never seems to get hot so I don't know if I can say I have a real heater. Radiator and thermostat were replaced, temp always hovers around 20% of the way up the temp meter when engine is warm, no coolant leaks. Input hose to heater core is too hot to touch and output hose is almost too hot to touch but not much differential so I thought the core fins were congested with dust and dirt (I already tried flushing out the core in both directions and it flowed freely). I removed the heater core and found nothing unusual! I could see daylight through all the fins and hosed water through the pipes in both directions and it flowed freely with nothing but water coming out. So now I'm perplexed and irritated (for doing all that work for nothing). Does anyone have an answer to this problem? I read all the past posts about heater issues and no help there (expect for heater removal tips - thanks). I would like to know about the following possibilities: 1. All the foam around the ducts and heater have deteriorated - would that cause loss of heating? If so, wouldn't the heat still get inside the cabin? 2. How do I replace all that foam? 3. If the heater core passages are clogged, would I still get free flow of water out the pipes? 4. Would soaking the heater core in cleaner make a difference under these circumstances? Any other ideas? I'm at a loss. It's cold out here in the winter time so it's worth it to me to get this repaired. Quote Link to comment Share on other sites More sharing options...
ihscout54 Posted January 19, 2015 Share Posted January 19, 2015 Tho Im not an expert with ea82 heater system this sounds like a classic blend door issue to me. I belive there is no valve to control coolant flow so heater operation is controlled strictly by which way the air flows. 1 Quote Link to comment Share on other sites More sharing options...
DaveT Posted January 19, 2015 Share Posted January 19, 2015 coolant always flows through the core. Both hoses hot means you have coolant flow. Also, you got free flowing of water with the other test, so that's not the issue. Blend door sounds like the problem to me. Quote Link to comment Share on other sites More sharing options...
john in KY Posted January 19, 2015 Share Posted January 19, 2015 Don't know if this applies to the loyale but the XT/XT6 has a switch just to the right of the gas pedal that controls the "doors". It is located behind a small plastic cover. If there, pop the cover and while someone else works the heating buttons, see if that lever moves. Also do know your car has a vacuum canister under the hood on the passenger side on the firewall. It needs to be hooked up for the heater to work properly. Quote Link to comment Share on other sites More sharing options...
Subarumor Posted January 20, 2015 Author Share Posted January 20, 2015 Hey thanks guys for the rapid response. Yeah, I checked the flapper door valve before I removed everything and it swiveled and I could hear the vacuum 'swoosh' sound so I assume the vacuum canister is working in the engine compartment (and I could see the hoses are connected to it). When I push the 'Heat' button, I can detect an initial warm flow of air that lasts for about 3secs then goes to room temp. so I'm thinking something is trying to work but doesn't last long. I soaked the core in soap and hot water overnight then blasted the fins with the water hose to clear them out and now soaking in vinegar to remove any possible deposits inside and out. I washed all the loose foam off the heater box and since nobody addressed that issue I can only conclude that might be the problem. I'm going to try putting some foam tape on it for whatever its worth. However, it seems like any vent leak would still warm the passenger compartment so I'm not too optimistic about it. . . . Quote Link to comment Share on other sites More sharing options...
Fish-N-Fool Posted January 21, 2015 Share Posted January 21, 2015 Hey thanks guys for the rapid response. Yeah, I checked the flapper door valve before I removed everything and it swiveled and I could hear the vacuum 'swoosh' sound so I assume the vacuum canister is working in the engine compartment (and I could see the hoses are connected to it). When I push the 'Heat' button, I can detect an initial warm flow of air that lasts for about 3secs then goes to room temp. so I'm thinking something is trying to work but doesn't last long. I soaked the core in soap and hot water overnight then blasted the fins with the water hose to clear them out and now soaking in vinegar to remove any possible deposits inside and out. I washed all the loose foam off the heater box and since nobody addressed that issue I can only conclude that might be the problem. I'm going to try putting some foam tape on it for whatever its worth. However, it seems like any vent leak would still warm the passenger compartment so I'm not too optimistic about it. . . . If the door isn't opening properly it will not push air through the core so no heat, or very little heat and cools quickly. Sounds to me like you need to confirm that the door works as it should Quote Link to comment Share on other sites More sharing options...
Subarumor Posted January 24, 2015 Author Share Posted January 24, 2015 Mystery Solved!: This should be very useful to someone else with a heater problem since I have not seen this 'solution' in any other heater post. After my experiments as stated above, I concluded that the heater core fins must be clogged up. But when I examined the core, the light was clearly passing through all the fin passages so I was stumped. I soaked the core in hot soapy water overnight just to clean it up for the install the next day. When I examined the soapy water the next morning it was totally black with dirt! Ah ha! So I rinsed the core clean with the garden hose, replaced all the foam on the heater box and flaps, tested all the flaps, reinstalled everything back to spec, and tested it for 2days. Result: the heater is pumping out warm air continuously now! Conclusion: the heater core fins accumulate a thin film of dirt over the years that reduces heat transfer to the passing air eventually causing 'heat stroke'. Lesson learned: "The neater the heater the sweeter". Quote Link to comment Share on other sites More sharing options...
DaveT Posted January 24, 2015 Share Posted January 24, 2015 Well, this gives me a possible cause and fix for the (low) heat in my 93! Quote Link to comment Share on other sites More sharing options...
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