Ok, so on my wifes car pretty much ever since she has owned it (3 years) the heat will stop working whenever the car is stopped. You can let it warm up and drive it all over the place and it will blow as warm as you could ever want it to. But the minute that you stop at a stop sign or traffic light the heat cuts out and it blows straight cold air. Anybody have any idea as to exactly what is going on here? I have heard people say the heater core is bad...but then why does it work fine when the car is running if it's bad.

Specs on the car:

2001 Mitsubishi Eclipse
3.0L V-6
135,000 miles
Front Wheel Drive

Any and all comments are welcome. I must say though that mechanically this car has been poorly maintained until I came along. We just got married not too long ago and before we did I requested that her father please put the time into getting the brakes done, oil changed, coolant flushed, and a tune-up since it really did need all of those things. He said he would and I assumed he did however it turns out he didn't do anything and it is now my burden to bear. I just recently found out that the brakes had worn down so far the rivets were beginning to dig into the discs, both rear wheel bearings have gone bad and were making a lovely howling noise...the plugs were all burned BADLY, the Cap and Rotor were extremely worn, and the head gasket clearly leaks LOTS of oil. So needless to say i've been putting some shop time in on this car. If we had the money i'd just buy a new one but since we already own this one putting a $1000 into it in comarison to $10,000 for a new one makes a lot of sense.

I figure while i'm already in there digging around I might as well try and fix the heat problem while i'm at it.

Thanks in advance for your advice,

Ryan

first question. when you are driving in a cold weather condition and this happens have you ever tried to check your fluid levels?

see once you turn your heat on a tiny diverter door opens and starts to run air over your heater core into your car interior. now a low coolant level will cause a problematic symptom like running cold air when stopped or idling.

second question. do you run a 50/50 mixture of coolant to water?

running too much coolant to water ratio during the winter although it works better for the "anti-freezing" of the fluid it also causes the fluid to remain thick at colder temperatures. therefore making fluid transfer a little more difficult at idle as your water/coolant pump is turning a lot slower 750 RPM in relation to just 10 miles a hour 2000-2500 rpm.

third question. have you recently done a radiator coolant change?

if in doing a radiator fluid change you find rust colored water and coolant there is likely to be a coolant leak in your system somewhere as the ingrediants for rust is water and oxygen. find the leak fix it or put in leak stop antifreeze. most likely it would be smart to just take off all your coolant lines and run water through them and any system they attach to as well, i.e: water pump, radiator, and heater core. put the entire system back together with a new 50/50 coolant to water ratio. heat up your motor and check for leaks at all the hose connections.

fourth question. does your wifes temperature gauge fluctuate while driving? or take a long time to heat up?

if this is also a problem your looking at needing a new thermostat. how long does it take your engine at idle to heat up? if it takes a long time, something like 20 minutes on a normal summer day, your looking at a thermostat that is stuck open allowing your fluid to flow constantly not allowing your fluid to heat up quickly in turn causing even more damage with a start up since heated oil flows better than cold. does your temp gauge get really hot, like up towards the overheating then suddenly drop? your thermostat is getting stuck shut replace it. you can also do this when you take all your hoses off to wash your system of rust particles like i mentioned on the question before.

if non of this helps you your looking at a expense of maybe $40 that you spent to maximize your systems efficiency, and this will tell you directly that you have some sort of internal problem with your heater core or HVAC system. therefore, for comfort reasons you need to replace your heater core. but thats just my opinion maybe someone else will offer you better advice, but i highly doubt it!

Ive had my car for over 3 years now. and my car has does this since day one. Ive had the coolant necks replaced lower and upper raidaitor hoses replaced thermostat. cooland flushed many times. and the last time the mitsu dealer i took it too sent the heads to see if they were cracked. (they were not) they explaind to me the only other thing they can do was replaced the small block which they did. and the problem is still here. i decided to take my car to midas and explaind them everything that had been replaced and why the issue was. they told me it was because i had the heater set on defrost which runs the a/c and is supposed to be cooler then normal heated air. could not answer why it would do this on every setting and why it was ice cold at idol. NO mechanic in my area seems to know what it is and im done putting money into trying to fix this....**** suggestion if no heat at idol is not something she wants to deal with get rid of the car its a money pit when it comes to this.*******

you have answered your own question, just get rid if it. make sure to buy a nice mid size luxury type car as the H.V.A.C. systems on them are generally 1,000 times better than any sports car. a nice Nissan Maxima, Pontiac Grand Am or Grand Prix, Chevy Malibu, Honda Accord, Hyundai Sonata, dodge intrepid, or just go for a Mitsubishi Galant. the Oldsmobile Alero's are super cheap, very nice to drive, fast, roomy, 4 door, a nd cheap on maintenance, just make sure to get the V6 though. the heaters on those are so good you have to turn them down because it will dam-near burn you when your just sitting there idling. its basically the same car as a Grand Prix or Grand Am. just not as expensive because 04 is the last year they were made. if you can find a dealership selling one in your area you can trade straight up for your Eclipse i guarantee it. if you want a bigger car you can go for a Chevy impala or a Monte Carlo. you can always get your wife a nice V.W. jetta those are always fun to drive. and with the options of a nice leather interior with heated seats is there as well.

trade in value for your car is 4800-5000, private party value is 6800-6200, and dealership will sell for 8,800. so getting your car traded for another car worth around 8,800 is more or less your goal range. if your wife sees a car on a lot worth around that price i suggest you walk in there with your wife and haggle it. because the dealership will end up with the same deal as they had before but they will now have a sports car to sell rather than a family sedan. its right around time for the dealerships to be busting out the 2 door cars on their lots anyways. and a 01 GT eclipse will easily sell before a 4 door in the summer. your not looking for a trade in your looking for a switch or swap. if you bought the Eclipse at a dealership in the first place just go back to them and ask if you can swap a car with them. i know a lot of dealerships that are more than willing to work with return customers. but i guess thats up to you.

Thanks for all of the good advice. I think the one about getting rid of the car is probably my best option here. The fluid levels of the coolant in the car are perfect and always have been...Her temperature guage doesn't bounce...the car heats up just as I would think it should...the only thing I can't attest to is the 50/50 mixture on the coolant. I think like you said I will drain the coolant system, rinse everything out, and refill this summer because like you said...it's a cheap job to know something has been done right. At least that way if it is running to thick it will help with cooling the engine this summer.

In my mind we will hopefully have a "newer" car before winter hits and maybe we just won't have to deal with that dang heater issue every again!!!


Once again thanks everybody for your great advice.




Oh and I just had a thought....What are the chances that this "little door" that opens to allow air to flow over the heater core to produce the "hot air" opens when the car is running since there is more pressure built up opposed to when your stopped. Is it possible that there isn't enough pressure to help to force the door open? It's probably a long shot but I just thought I would throw that out there.