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Athlon64~SPARTA~
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Got a Question about your car or truck? Every wonder how that works? Or whats going on in there?

Well ask a pro certifyed mechanic that has 30 years experence.

Ask away and i will be happy to help you, or guide you, Or just need advice? I have on line access to Micthel on demand and can supply you with wireing diagrams and torque specs on just about every thing made.

So ask away! Im all ears.

Areas i cover

Heavy duty air brakes

Hydrolic brakes

Air conditioning

Computer codes

Starting

Charging

Electrical

Engine

Manual trans

Clucth

 

Fire Appratus:

Cat

Detroit diesel

Hale fire pumps

Waterous fire pumps

Champion Darley pumps

Allison WTEC transmissions

Ackron fire valves

Elkhart fire valves

Fecon Afff perportioning foam systems

OSHKOSH Balance valve foam systems

Central tire inflation systems CTIS.

Leece neville Altenatiors

Certifyed appratus NFPA pump testing tech.

Edited by Athlon64~SPARTA~
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Okay I guess I'll be first.

 

My wife drives a 2001 Ford Taurus SE, 6 cylinder.

Recently we found a crack in her fill tank for engine coolant (green kind not orange) it would heat up after driving it and then spew all over the ground, I spent a ton of money on coolant after we realized that her coolant was leaking. Before I started adding filling it up and trying to find the leak, we dont know how long it ran almost dry before finding the crack in the tank.

 

Now, her heat barely works but the tank has been replaced, and the coolant topped off. My guess it is the heater core being clogged with debris, but I am not sure. I will take it to a trusted mechanic and have them diagnose it.

 

So the main symptoms and history are:

 

heater did not work very well

had leak in tank that allowed for the coolant to leak by the gallons.

Car was run without full coolant (dont know how much or how long for)

 

leak was fixed and coolant replaced.

 

the heat still does not work

***

Should the heater core be flushed and if that doesnt repair the problem, replaced?

 

Thanks Athlon

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Well that tank is more or less a recovery tank and its above the radatior, or next to it, so chances are even if it ran dry the radatior was still full, as long as it never over heated your ok. Now as far as the heater goes. there could be 2 things affecting that. 1 maybe if the coolant got low and there could be a air pocket caught in the heater core and that would cause a air lock in it makeing it not heat as good as it should. That can be fixed buy pergering the air out of it buy takeing loose one of the hoses just enough to gas out the air untill coolant comes out. And of coarse do it cold, not under pressure. And be carefull the heater core hose hook up nipples are delacate and might break easy. 2 could be maybe a missajusted heater controll at the heat controll knob on the dash heat controll unit. Or maybe a slow dash pot or vacuum actuater in the heat blend door in the heat system. or could also be a vacuum leak out under the hood causeing the shutter doors in the a/c /heat system to be slow, sluggesh our not fully moveing the doors enough to blend heat in, Check your vacuum lines out under the hood to make sure none are broken. and check if when changeing the controlls from defrost to floor heat, it actually does it and does so fairly quickly. if its slow then the problem is in the vacuum side of the system.. if all that works ok then it will be in the coolant side of it, buy eather needing blead or may be restricted. I think the tarus only uses a blend door heat controll and not a valve like older cars did, that went from the knob on the dash to under the hood to the heat shut off valve in one of the heater hoses. and it could aslo be the engine is not getting hot enough to heat properly, make sure the engine reaches operating temp 195-212 degrees, on a short trip it may not be warmed up enough.

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Oh I also forgot that at the main vacuum sorce on the engine intake manfold ( where all the vacuum lines hook up to the engine) follow the one that heads tward the heater/ac condenser box on the passenger side fire wall, there will be a small looking disk in the line.

That is the vacuum check valve and should only pass vacuum one way, tward the engine. If it passes bouth ways then that would cause a low vacuum condition at mid throttle and a drop in vacuum to the vacuum actuatiors causeing the shutter doors to close up= thus not heat also. Great illstration halli!

Edited by Athlon64~SPARTA~
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Not a bad idea here. I run a service department for a International Truck and Engine Corp Heavy Highway truck dealership www.southlandit.com and have 17 techs under my wing so as well a great big vat of diesel knowledge is also available. Plus when Halli needs some International parts help, Ive been known to lend a hand eh buddy!

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I've had this same type of problem before in many different Ford's, LTD, Bronco, Explorer, etc. Each and every time it ended up being the same thing. I even had a friend with a Taurus that did the same thing and I helped him fix it. The problem is the one hit on by Halli and one of the simplest, even though the symtoms don't make it seem like it, it is probably the Thermostat.

 

Likely stuck open after it was initially stuck closed. It was probably stuck closed, boiled up in the block enough to open the thermostat, but the thermostat didn't open the way it normally would. Instead, it stuck closed for longer than it should until the back pressure was way more than normal, then blew open, sticking it in the open position. When that happened, the sudden release of pressure from the block into the radiator caused the rapid expansion of the boiling coolant that overflowed into the reservoir and leaked out the cracked reservoir. All this can happen without the the car registering overheated on your dashboard indicator.

 

If I were a betting man, I'd place a fiver on that.

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Well yes, But it should never happen if we maintained our vehicles properly, Replaceing the thermostat at the regular service intervels and flushing the cooling system and replaceing the thermostat at least once a year.

 

Ya I know i Sound like a service manual, But that stuff is in there for a reason. Even I don't do it eather. If the coolant gets to low in the engine block it will uncover the tempature sender unit and won't regester on the dash indacatior gauge. But with these new Alumnuim engine blocks or a cast iron block with alumnuim heads. the expansion rate is different inbetween the 2 different metels and will useally blow out a head gasket.

 

If that occures then it opens up a whole box of worms. Compression can leak into the cooling system and force out all the coolant. OR it will draw in the coolant and burn it along with the air/fuel mixture. Or the coolant can leak into the crank case and thinn out the engine oil, In wicth case Its buy the farm time.

 

Thats a big factor in when i buy a vehicle, I look at the engine and i useally get a vehicle that has the same metel in the cyclinder head as well as the block to minimize wacky dissimular metel problems. I also stay away from over head cam engines with rubber timeing belts as well, as they have a reputation for being self exploders.

 

Not allways true for all the outher vehicle mfgers out there, it differs greatly from one to anouther.

Edited by Athlon64~SPARTA~
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hmmm... I might be wrong, but I think the problem might be a bit simpler yet.

 

What if it is the radiator cap? If it is spewing all over the ground, the cap may not be holding the original design coolant pressure. Especially if it is not running completely out of coolant and the engine didnt overheat. The radiator cap pressure spring (especially really old ones & aftermarket ones) can weaken to a point where they release pressure below the coolant system's design temp range. This would explain it not losing all the coolant as normally the cap will eventually close again as the temperature and resulting pressure drops.

 

Your description as follows:

If the engine doesn't overheat but it spews coolant all over the ground from the holding tank. In addition the heater produces little or no heat.

 

- if the thermostat is stuck closed, you almost always get an overheat indication.

- if the thermostat is stuck open, the engine doesnt warm up to operating temperature causing little if any heat from your heater because the coolant is too cold. Usually the coolant doesnt blow coolant out of the resevoir.

 

A radiator cap releasing pressure too low will cause both of the problems you describe as it would blow off pressure as the thermostat opened at the proper temperature and resulting higher pressure.

 

If it isn't the thermostat or the rad cap... then Athlon's more serious situation might be pumping cylinder pressure into the coolant system. I don't know where the temperature sensor is on that coolant system but; If enough coolant is lost, and no coolant is in contact with the sensor, it will not show an overheat. The temp sending unit cannot measure air or steam temperature accurately.

Hopefully it is on of the more pocket book friendly versions.

 

Am I wrong about the radiator cap possibility guys?

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Not at all wrong. Sometimes its the simplest things we over look first! 13 to 15 lb cap. But isent it the whole idea to pressureize the system to reduce the boiling point of the coolant? and if the pressure was lost wouldent the coolant boil quicker, sooner?

 

Thats what makes me lean closer to a air lock or blend door, or maybe even a thermastat. But again if it was a themostat, then the OBD computer would be setting MIL codes to the fact that the engine is never reaching proper operating temp and not going into closed loop and the est kicking in causeing the engine to stay at base timeing ingnoring the o2 sensiors.

Edited by Athlon64~SPARTA~
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Ok Medic did some checking on it, and found that the heater system is controlled buy the the body computer and what they call the manual or the digital controls are all controlled electronicly, and it has a electric blend door motor that moves the door back and forth to eather increase or decrase heat.

 

In eather case the body computer controls it, and has its own trouble codes for the heat HVAC system. The only manual things you can do is feel the heater hoses to see if they are bouth hot, That would indacate that indeed you are getting flow in to and out from the heater core.

 

Any more dienostics just about has to be done with a computer scan tool. You can increase the heat on the dash controll and listen to see if the motor is running and moveing the door. After long winded speculation buy all, Thats about it.

 

There has been service up dates, TSBs as to the core leaking, but are only covered wile the car is still under warranty.

Edited by Athlon64~SPARTA~
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No, on the OBD computer system you have to Turn the ingnition swich on and off rapidly 3 times untill the MIL light comes on and starts flashing codes at you. But the body computer codes are second layer code and may not come out on the main MIL = Your thinking of the old GM ecm code system, due to its a secondary body computer, I could be wrong on that thow. And its worth a try,

 

If it does spitt out codes at you write them down and I can get you a code sheet and wireing dieagrams and scematics on it includeing pin outs and the such.\

 

A good article on it

http://www.samarins.com/diagnose/checkengine.html#diy

Edited by Athlon64~SPARTA~
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Well I am not a tech but The reason I commented was I just had the same deal with my 5.8L Bronco and It turned out to be the Thermostat, after removing the old one I noticed the tang that held it open.

 

It runs fine now and I do not need the cardboard in front of the Radiator to heat the truck.....haha I used one split in two so I could slide it half way or all the way covered to adjust according to the temp outside. :rolleyes:

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