No heat in my car

[bomelia]

Yes, I still have that stupid car. And again, no heat. (98 Grand Marquis). So, I flushed the system, then plugged a water hose into the heater coil and blew water through that while the car was running (somebody here I think suggested I do that). Still, nothing.

Whats left? I could hear no vacuum leak under the dash. The control for temperature is electronic... maybe something has failed on the circuit board? Not sending a signal to move some baffle so the air passes over the heater coil?

Mike

[4RE KLR]

Mike
Just a thought here, OK

Look under the dash and see if you can find the duct work for the system. In some of my old trucks (yes, I know it isn't a car) I could actually see the cable that lead to the door that opened and closed the system that let the heat in.

Maybe, if you can get to it, you can close the door manually, and let the heat get into the cabin. Now it seems if you are just by-passing the interior of the car.

I don't know if you can get to it in your car, but it is just a thought.

[427 S/O]

Mike, I did mention earlier the flap in your blower system, under the dash, might be the problem. It was on mine. The defrost-floor-dash cable might be broke or, slipped off?.

[imagine2frolic]

Mike,

Be glad you live as far south as you do.....lololololol.....i2f

[Ron61]

Mike,

You are in Alabama. You have Humidity to take care of the little cool weather you have once in a while. Although I did see that places there were colder than In Alaska the other day.

Ron

[Wes Tausend]

Originally Posted by bomelia

Yes, I still have that stupid car. And again, no heat. (98 Grand Marquis). So, I flushed the system, then plugged a water hose into the heater coil and blew water through that while the car was running (somebody here I think suggested I do that). Still, nothing.

Whats left? I could hear no vacuum leak under the dash. The control for temperature is electronic... maybe something has failed on the circuit board? Not sending a signal to move some baffle so the air passes over the heater coil?

Mike

Mike,

"flushed the system, then plugged a water hose into the heater coil and blew water through that "
It's important to blow in the reverse direction from normal flow and the car doesn't need to be running. It's not unusual to get a 1/4 cup of junk out even from a good heater. The core acts as a filter for system flakes. If "water-in" is hot and the "hose-out" is cold, then water flow is impeded and the core is getting all it can out of limited hot water.

If the doors are vacuum operated, I think may be a vacuum problem yet. Normally the vacuum is attenuated with a slow pinhole feed (hard to hear) so it doesn't slam the doors when new. Still, normal vacuum smoothly gradually builds up to full level, as in new, if the electronic control works and no tiny downstream leaks pizz it away.

As the car ages, the doors get stickier. Sometimes dust sized debris or seeds sift in and jam the doors. At the same time peak engine vacuum drops and vacuum line hoses tend to develop minute leaks. End result: slow operation and eventually nothing, from multiple causes.

Try springing vacuum diaphrams against their springload and see if they leak back faulty while you hold your finger over the diaphram vacuum line inlet. I like mechanical cable op better than vacuum because it's more stone-reliable.

We are very heater minded up here.

Wes


...

[wtm442]

Mike
I have the same car (98 Grand Marquis de Sade) but I got plenty of heat.

If you want, stop by my house and you can have my Merc. It needs tires, exhaust system, cat converter, ac compressor, horn does not work and wipers are a little screwy, but it has tons of heat. Valid sticker ??? Fagetabodit.

Only 130K miles so its just broken in (just a little bit of rust). I just doubled the sale price cuz I filled the tank with gas.

A cheaper alternative is to put a big aluminum turkey pan (the cooking type, not the Cobra air cleaner type) in the passenger seat footwell, add some newspaper and small twigs ... a single match and viola ... heat. It works, especially in 1968 Ramblers ,,, ask me how I know.

[bomelia]

Some of yoose guys are too dam funny. Friggin believe it or not, its COLD here now. I will try back blowing the coil and also try to figure out where the "flapper" is.

Mike

[trularin]

Mike,

Reverse flow of the heater core can be done with a gallon jug of hot tap water. This will tell you a lot.

1. Remove both hoses from the heater core.
2. connect a short hose and funnel to one side of the heater core.
3. pour the hot water ( the hot water you get out of the tap is fine ) into the funnel.

Now look at what happens.

4. if the water drains from the funnel and no water comes from the other end, you have a leaky heater core.
5. if the water drains from the funnel and come out the other end, look at the condition of the water. Lots of gunk means you are cleaning it out.
6. if the water does not drain from the funnel, the heater core is plugged.

So, you put a gallon of water through. Now do the other side.
You should switch back and forth until you can get water flowing both ways.

If the heater core is plugged. You can use 15 PSI of compressed air to force blockages out of the core. Be very careful, pop the core and you will not be happy. To do this, place a rubber hose that fits inside the heater core nipple. Scale the opening down until you can fit an air nozzle into the nipple without it leaking. Then you will need to an inner tube. Fill it until it reads 15 PSI. Stick the fitting of the inner tube into the opening you just made and let the ait escape.

This works sometimes.

Hope this helps!!

[wtm442]

Originally Posted by bomelia

Some of yoose guys are too dam funny. Friggin believe it or not, its COLD here now. I will try back blowing the coil and also try to figure out where the "flapper" is.

Mike

Hopefully, not when its running!!! Whatever you do, do not believe that old tale about sucking on the tail pipe.

[Ron61]

Mike,

Scott has extra wood for sale. Maybe a fireproof floor pan on the passenger side and you would be in business.

On the serious side, I don't know where your heater radiator is located but the ones in my cars are on the inside and behind the darn duct work and a ***** to get to. I had to change one a year or so ago as it was leaking and the water and anti freeze was showing up on the floor mat. And my cars are older, but I did have the loop from the pull knob slip off one of the flap openers once that directed the blower air from the defroster tom the heating ducts. Good luck.

Ron

[bomelia]

Well, I know water will flow in one direction, so I will try the other direction.

If the water flows in both directions, does that mean the heater coil is AOK?

There is no leakage inside the car.

Mike

Originally Posted by trularin

Mike,

Reverse flow of the heater core can be done with a gallon jug of hot tap water. This will tell you a lot.

1. Remove both hoses from the heater core.
2. connect a short hose and funnel to one side of the heater core.
3. pour the hot water ( the hot water you get out of the tap is fine ) into the funnel.

Now look at what happens.

4. if the water drains from the funnel and no water comes from the other end, you have a leaky heater core.
5. if the water drains from the funnel and come out the other end, look at the condition of the water. Lots of gunk means you are cleaning it out.
6. if the water does not drain from the funnel, the heater core is plugged.

So, you put a gallon of water through. Now do the other side.
You should switch back and forth until you can get water flowing both ways.

If the heater core is plugged. You can use 15 PSI of compressed air to force blockages out of the core. Be very careful, pop the core and you will not be happy. To do this, place a rubber hose that fits inside the heater core nipple. Scale the opening down until you can fit an air nozzle into the nipple without it leaking. Then you will need to an inner tube. Fill it until it reads 15 PSI. Stick the fitting of the inner tube into the opening you just made and let the ait escape.

This works sometimes.

Hope this helps!!

[Sharroll Celby]

Here's a shot in the dark: Make sure there is not a whole lot of leaves and other dirt covering the vent(s) at the base of the windshield, just behind the hood.

[bomelia]

That is not a shot in the dark. The other day when I was doing this, I noticed a TON of crap there. Pine needles, leaves, whirly gigs, dead animals, live plants, etc. I cleaned all that off. It was very thick. But removing it did no good. Do you think some of that crap got down in there and is messing with the flapper??

Mike

[Sharroll Celby]

Maybe start again with the simple stuff. Maybe a wire became disconnected from the electronic controls.
Can you SEE anything under the dash, like maybe a loose/broken cable, vacuum hose, or wire?
Do you know anyone with a similar car, that you can look at, or give a listen to?

If all else fails, pretend it is a Cobra Sedan, with NO heater!

[Wes Tausend]

...

Mike,

I thought of a couple of added tips.

The way to determine the "in and out" of the heater core is to note which heater hose connects to the bottom of the engine/pump near the main radiator hose that goes to the bottom of the radiator itself. This is the heater-core-out hose since this main radiator hose always draws coolant from the bottom of the radiator. Instead of the funnel/bucket method, I usually feed garden hose water back up this hose to blow out debris. Dirty water will flow out the other disconnected heater hose into a bucket if mess is a concern.

The debris is actually worse after you have run power-flush solution through the system after a long lack of attention, since it loosens up accumulated rust flakes from the engine block. In case performance noticably falls back off, there is often a bit more remaining system junk again "filtered out" by the heater core, partially replugging it again a week later. Tedious, I know.

To check the thermostat and possible excessive thermostat bypass leaks, feel the upper radiator hose (running) when the system has not yet come up to full gauge temperature. Only after the thermostat opens, should hot coolant flow into the top of the radiator, which may have an air pocket (and out the bottom which has a constant liquid supply to feed the waterpump).

If the thermostat and bypasses are operating correctly, there will be no significant hot coolant being wasted in the main radiator unless the engine is up to full temp. When thermostats fail (or are defective when new) they usually fail by staying open. A cold engine may impede heater operation, but may also trigger a computer to continue to run in rich mode, burning more fuel and carboning up the engine.

Nothing is more disgusting than a bum heater except maybe no-start.
I know a lot of guys here wouldn't recommend you feel your hose like that.
But a lot wood.

Wes


...

[bomelia]

Well I will look at this tonight. I guess I am surprised that water can flow in one direction through the heater core, and yet not the other direction (at least that is what I am hearing). I do not think the thermostat is bad. I unhooked the bottom hose to drain the system. Then, after the radiator was empty, I started the car. After about 2-3 minutes, water started flowing out of the hose radiator again. Once it emptied, I was able to push water through the system via one of the ports on the heater core.

Mike

[Ron61]

Mike,

I know that this is a dumb question and others may have asked it and I just missed it reading the posts, but does the defroster work? I am not familiar with your cars setup, but in mine the core is inside the car and the defroster gets its heat from the core and it is just changed from heat to defrost with a slider which physically opens and closes a door in the duct work under the dash. If the defroster works, then I would suspect you have a door in the duct work not opening or closing. I am sure this has already been covered in previous posts, but getting to anything in my car under the dash is a real pain in the A**.

Ron

[Barn$nake]

Mike,
I have not worked on a Merc, but several Windstars
and Fords. Pull off the motor for the blend air door (easy)
and inspect the motor and the door coupling.It seems
the trucks would break the arm off the door, but the cars
would break the plastic on the motor.Good Luck
Ed Paz

[bomelia]

Ron,

Air comes out of the defroster (cold).

Paz, I will try that! More and more I am becoming convinced that it is an air flow control problem. I'm still going to blow water through the core in the opposite direction to be sure... but I still do not understand how it could flow one way and not the other.

Mike