[BelAir67]

Okay, I've read several topics on this subject, but I'd just like to cover all the bases with this one. Just replaced the thermostat on our 99 Taurus Vulcan because we've been getting either no heat, lukewarm heat, and some case when the stars are right, good and hot heat. The car runs at normal temperature and shows no signs of even being close to overheating. So I figure it can't be a heater core if I actually get heat once in a while, right?

So here are the questions:

1. Will air in the cooling system affect the heater?
2. We've had to add some fluid lately. Will low coolant levels affect the heat?
3. What about this 'blend door' I've heard about. How can I tell if it's working and how hard is it to correct if it isn't?
4. Could it still be a heater core if I got hot heat right after I replaced the thermostat? (and every so often)

Other than the heat, the car acts, looks, and runs fine. Don't see any fluid or steam coming out (but that doesn't mean it isn't leaking when I drive I guess).

Thanks!

 

[Guest]

Air in the system will affect it's performance. When the car's cold, remove the degas bottle cap (radiator cap on this car), start the car and let it reach operating temperature. Run it for a little while like this and that should get the air out of the system.

Low coolant levels will also affect the heater's performance.

Is the coolant a brownish color?

 

[SaturdaysSHO]

Bob is the man, he knows about this problem with Vulcan Taurus'. One thing I would like to add. I think you should flush your cooling system. This is why. My Taurus' heat started to act like yours but got progressively worse, and I think if we (my father and I) hadn't let flushing the coolant system go. We wouldn't have ended up having to get a new heater core (re: costly)

Nick Saturday

Thats my .02, but just listen to Bob!

 

[Guest]

I had the same problem with my 99 vulcan and had to have the cooling system flushed & filled 8 times - and the last time was a "power flush" from the stealership with something so potent it ate through hoses and they had to replace them. But after all that it started working. However, this was on a car that had been driven about 65k miles with ZERO maintenance by the previous owner, pretty much nothing other than oil changes.

Forgot to add - several months after all this they wound up having to replace the heater core, too.

 

[fvt]

this is EXACTLY what happened to me. At first i thought it was the gasket blown or something as there was smoke coming out and coolant was losing in huge amounts. A friend checked all pipes (coolant) and lines and saw a huge Slash in the heater hose. (Looks like one of the mechanics did it delibrately to bring the car back since there are no moving sharp objects in that area.) Here is the diagram of myhose damage. Just changed the hose and changed the coolant and it is ok now.


My symptoms included:
Hissing noise (Air escaping via slash in the hose)
Loss of coolant
Excessive smoking as coolant began to pour into the hot engine...looks like the front of the car is on fire
Fluctuation of Temp guage as air enters coolant lines via open hole/slash

Good thing was there was still coolant in the engine when i checked it or the entire engine would have been a toss.....head gasket would have been done if this was the case.

 

[BelAir67]

Hey guys, thanks for all the leads I've gotten so far..just thought I'd give you and update:

The system was flushed and filled back in November 2002, and as of Sunday, the fluid was a nice, pretty green. I can detect no leaks, although back in December and recently I had to add some antifreeze mix. I cringe everytime y'all mention the words 'heater core'--let's hope for the best

I tried the suggestion this morning of letting the cap off, warming it up, and then replacing it. Well, sad to say, still no heat, or at the very most, lukewarm heat. If I have the dial on cold, of course I get the cold outside air. At full heat, I only get that lukewarm deal. And as I mentioned, the car acts fine and the temp guage is just a bit below halfway.

Keep throwing out ideas if you have them and I'll keep y'all updated. Guess I won't actually need the heat in a month or so, but it would be nice to have it functioning.

 

[Guest]

OK let's try this next. Let the car warm up, put the heat on. Feel the heater core hoses near the firewall (careful for moving engine parts). If both hoses are hot, it's a blend door issue. If one hose is hot and one is lukewarm, it's a plugged heater core, and the system, including the heater core, needs to be backflushed.

 

[BelAir67]

You know, I felt a lot of hoses yesterday trying to determine that very question. Now, I'll be the first to admit, I'm not the expert on which hose is going where, but here's what I know: A smaller, heater hose look-alike thingy coming from the water pump is hot and under pressure. A similar looking hose on the right hand side of the engine (looking at it from the front) and attached somewhere near the thermostat is also warm and under pressure. Every single hose, whether I think it relates to the heater or not, located near the firewall all seem to be hot and under some sort of pressure.

Oddly enough, the heat is getting slightly warmer as I drove it more today, but stay WAY too cool. I've been rapidly playing with the heater knob hoping that might do something. Should I be hearing some kind of noise when I adjust the heater temp? I am hearing noises when I go from vent to interior to A/C and such from the other knob.

 

[Guest]

The two hoses you mentioned are the heater hoses, and they should feel like they are at the same temperature once the car is warmed to operating temp.

As far as the heater controls, on my 97 I can hear the vents changing position, but not the blend door moving when I adjust the temperature knob.

I hate to say it, but at this point, if both those hoses are hot, you may have a blend door issue that needs to be looked into.

 

[BelAir67]

Okay, here's what I noticed at lunch: I drove the car for a while and got that lukewarm heat. Then, it seemed like it got colder as I went. So, I turned the knob all the way back to cold, let it cool, and turned it all the way back to hot. At that point, I got heat again, although as I've said, not great heat. Is this indicitive of a blend door problem?

And not to sound like a moron--does the water flow from the top of the engine, to the core, and back to the water pump, or does it flow out of the pump in the other direction? I'm just trying to confirm exactly which hoses I need to feel and which ones coming from the firewall are the real indicators.

 

[BelAir67]

Hey guys...any chance this could still be a heater core problem? And if it is, would it be plugged, leaking, or just flat not working?

For that matter, anyone know the current rate for fixing either a heater core or blend door failure?

 

[Guest]

If both hoses are the same temp, then it's most likely a blend door issue.

For labor on the heater core, figure about 6-8 hours. The dash needs to be disassembled. Not sure on the blend door, because it could be a broken vacuum line, faulty knob/actuator, etc. It all depends on what the issue is.

 

[BelAir67]

Fortunately (or unfortunately, however you look at it), I work at a place that has it's own mechanic (mainly for HD trucks). He had a chance to look it over thoroughly and says he can feel the heater hose going into the core is hot, while the one coming out is lukewarm at best. He seems to think a backflush on the heater core might be the trick.

I'm going to take it tomorrow, ask the garage (which does all our work) to verify that that's what's going on, and recommend a course of action if they feel it is something else. But right now we're thinking plugged heater core.

I'll keep y'all updated.

 

[BelAir67]

Sorry to bother y'all--just an update. We have heat! Turns out it was just a plugged heater core. Garage said they were going to blow out whatever they could from the heater core with compressed air. Said they got a lot of brown water out of the sytem.

How long is antifreeze supposed to last anyway? I had the thing flushed in Nov 2002 and the water was already brown? Geez, they don't make antifreeze the way they used to.

 

[Thomas J McKeon]

Low radiator reservoir full not overheating no heatfrom heater

I had this problem. I put 1/2 gallon of Vinegar and a bottle of Prestone radiator cleaner (citirc acid) and left in car for one day. Then I followed Bob Gervais suggestion about taking the degas-overflow cap off to remove the air. I did that twice and I had some heat out of heater. Decided to flush vinegar & Prestone cleaner out of system and put in new antifreeze and took to mechanic to put on lift. When he removed bottom hose from overflow reservoir to drain it, nothing came out deven tho it was full. Hose was stop;ped jup with what looked like brown was odf chewing tobacco or 2" of a Churchill cigar. Removed that and the water pored out. Stoppage was right at point where bottom hose makes an "L" turn after coming out of reservoir before it goes back into radiator or engine (not sure which). Anyhow I have very hot heat now, and it cost me around $70 including 50/50 antifreezemix-I opted for that since garage did not have distilled water and the water heere in Indianapolis is so ful of calcium I have to put vinegar or citric acid on shower head every two months to unstop it. I think it was mostly the plugged up bottom hose, tho Bob Gervais' suggestion about getting air out by leaving cap off while warms up did make significant diffeerence and vinegar (ascetic acid) and Prestone cleaner (citric acid) in for two days did seem like it helped. Thomas J McKeon

 

[behlinla]

Wow, you're lucky you didn't overheat and damage the engine with that blockage preventing the coolant from filling the system.

Good plan going with the 50/50 premix since the shop didn't have distilled water.