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It's cold and I don't have much heat! HELP


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So....as some of you may know I just pulled the engine on my 92 Loyale S/R 4WD 5 SPD. I thought it was the clutch....Well not quite....The fork cracked. Anyways, before and still now, I don't have much heat. I even took the mechanical fan off and left it off! So, I'm not sure why? I tested the hoses going into the and out of the heater core. They are about the same temp. with the heater fan on and off. If the car just sits and runs forever the electric fan will switch on and off. I don't think the heater core is plugged. I say this because as I'm driving down the road the gauge goes down to bairly above the mark after the C. I touch the radiator and it is cool after a drive too....It only gets "HOT" after it sits and runs for sometime. So, any ideas? It does have a new thermostat, which seems to be working?@?!! All new coolant and oil....SO, any ideas? Sorry this is so long. Trying to cover everything.

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If the car just sits and runs forever the electric fan will switch on and off. I don't think the heater core is plugged. I say this because as I'm driving down the road the gauge goes down to bairly above the mark after the C. I touch the radiator and it is cool after a drive too....It only gets "HOT" after it sits and runs for sometime.

 

Get an actual subaru thermostat.

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First, follow the above advise about using the correct thermostat. This is not to knock the thermostat theory, because it's a good one... Aftermarket T-stats do not work right. This could prevent your cooling system from ever reaching the "Normal" operating temperature.

 

However, assuming your cooling system and t-stat are working correctly, I was thinking perhaps the blend door in the air box may not be opening all the way, or at all for that matter... Do you have good airflow coming out your vents? The seals on your air box may be bad, as above stated..

You mentioned both heater hoses are the same temp, but you did not say if they were almost too hot to touch... This would be the indication that your cooling system is fully warm.

 

If your cooling system is running above 140deg, you should have plenty of warm air coming out the vent if the blend doors on your air box are working correctly. I might suggest that you check the vacuum motors on the air box and see if they are leaking vacuum, and perhaps not pulling all the way to one side... provided your cooling system is warming up to operating temp, that is...

 

EDIT: Gloyale is correct, it's a cable goes from your heater control panel down to your air box, not the vacuum system... (see below for details) My Mistake....Still, definately check the vacuum motors.

Edited by 88RxTuner
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However, assuming your cooling system and t-stat are working correctly, I was thinking perhaps the blend door in the air box may not be opening all the way, or at all for that matter...

 

Good call.

 

The blend door is operated via a cable, it's easy to find. Runs down along where the drivers feet go, just to the right of the gas pedal. Now, the cable operates a bevel gear, the bevel gear drives the flap.

 

I have seen it happen before where the bevel gear set gets out of whack. Only seen it once, but after I reset the gears to the proper engagement(IIRC, you want the driven gear to pivot *up*)

 

I forget about that issue sometimes, again becasue I have only seen it once.

 

Aslo for max heat, find the vac tube that runs behind the glovebox to the fresh air inlet actuator.(it's the only one you can see behind the glovebox, over the blower motor area. disconnect that vac line and plug it. Now you will be recirculating inside air instead of pulling in cold air from outside.

 

Canadian models have a button to do this.

Edited by Gloyale
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Well, just got back in from washing and checking the blend door. It seems okay. Moves to it's fullest "open and closed" position with and without the cable attached. So, I checked the airbox behind the glove box. I believe it's leaking. I can feel cold air from there. Would it be cold air or warm air blowing out of there? The cold part kind of throws me off. If this is the case that I need to reseal it, how would I go about doing that? Thank you all for your help too....Oh, BTW. The hose between the thermostat is very warm...And the one from the lower part of the radiator to the pump is much cooler. Maybe that info could be important? Both heater core hoses are about the same temp and about the same temp as the thermo to radiator hose.

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The upper hose is where the hot coolant goes from the engine to the rad, the lower is the coolant going back to the engine after the heat has been removed from it in the rad, so all that is normal. But while driving the gauge should not drop, it should go to about 1/4 inch above resting position(start up) and stay right about there. I know temps are different between Colorado and Virginia, but last week it was 4 degrees when I left work one night , and after a brief warm up, the temp gauge climbed up 1/4 inch and stayed there for the 40 mile drive home. It sounds like your thermostat is stuck open. Not uncommon to get a bad new thermostat. Take it out and you'll see if it's open or not. Sometimes you can tap, and I mean tap not hit, the thermostat housing with a little hammer and it will jiggle it enough to close it. But to be sure get a new one. That $7-8 part can destroy an engine. You can put a piece of cardboard in front of the rad covering about 75-80% of it and see if that makes a difference. If it helps, you need a new thermostat.

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I will go cover it with a little cardboard right now and see if it helps tonight at work. If not than maybe it's the leaking air box? Maybe I should call my local Subi dealer and get a new one. I replaced it just a few weeks ago...Might have gotten a bad one.

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seems like just weekend before last I replaced the foam seals of the air box clamps, and last weekend installed working resistor pack and rear wing :banana:

 

think about the air flow of the system: fresh air enters the system at the cowl, goes down to the blower motor, across the condensor, and then runs into the temp control door, if COLD is selected, air goes up the ductwork box behind the radio bypassing the heater core!, but if HOT is selected the air goes through the heater core and then to it's destination, so when the door is less than 100% either way, a BLEND is created

 

if RECIRC is selected, the air from passenger footwell is sucked up into the air box above the blower motor, and on down the stream it goes

 

if there are any leaks, passenger gets the cold air blown at their feet

 

 

I used wide gap pvc closed cell foam gray 3/8 x 1/2 x 10ft item # 204 Dennis http://www.wjdennis-rcr.com/pdf/weatherstripping/foam_tapes.pdf

 

the large clamp was easy to remove with the box is position

I removed the air box that holds the blower motor and the air box that holds the AC evaporator to repalce the seals

 

the evaporator had accumulated alot of crud and leaves, and is now sitting with the rest of the AC lines and parts in storage

 

all "gaskets" were deteriorated or non-existant

 

there is a "gasket" between the body and air box that holds blower motor, remove under panel, glovebox, glovebox brace, fresh air duct, etc. to access

 

once AC evaporator lines are disconnected, and clamps loosened, it is possible to remove the AC condensor air box to remove the last clamp

 

remove all of the old "gaskets", then apply new foam, sticky side down to metal

when installing the foam, you will need to apply a strip to each 1/2 of the clamp, the CL is quite obvious

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I will go cover it with a little cardboard right now and see if it helps tonight at work. If not than maybe it's the leaking air box? Maybe I should call my local Subi dealer and get a new one. I replaced it just a few weeks ago...Might have gotten a bad one.

 

The lack of heat shown on the gauge is a big clue. If you don't trust it you can install an aftermarket coolant temp gauge from any parts store or $20 or so, but you need the metric adapter to mount the sender to your engine. I mounted one once in the same spot the temp sender for the dash gauge was, just didn't have the working dash gauge for a while.

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+1 on gauge reading... IF the engine is truly not warming up, this could be your root cause.

I would agree with the above mentioned suggestions of using a Subaru Thermostat.. I have run too many engines with WAY too many 'Kragen Brand" thermostats, Stant, Universal Cooling, Etc whatever, and pretty much all of them fail either immediately or in an unfortunately short period of time.

The blend door suggestion was simply something off the top of my head, I would suggest you check and replace your Tstat with the factory issued unit...

88RxTuner

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Well, Now that I've driven it a little more I think it's a combination of bad thermostat and clogged heater core. If I let the car just sit and run long enough it does warm up and stay fairly warm. I can turn the heat on and it's pretty darn hot. But, only for a minute or so. Than it starts to cool down. At this point the gauge doesn't really drop, not untill I actually start driving than the gauge really drops. So, I am thinking I need to "flush" out the core and get a new thermostat. Any best methods of flushing the heater core work better than others?

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quote:

Any best methods of flushing the heater core work better than others?

end quote:

 

Best method I've found for any heater core is;

 

garden hose thru heater hoses, swap back and forth between the hoses a few times. Make sure any shut-off valves are open....

 

Along with using;

 

NAPA's, MAC's Radiator Cleanser, it's some good stuff for boiling out "any" closed-loop water system(s).

 

I've used it many times on vehicles and in "other" systems where crud can/will build up.

 

Directions say to leave it in for 20 minutes, but I've ran it for a few days with no ill effects.

 

It will foam if Anti-Freeze is present, but you can get around that by mixing it in a bucket of water, pour it into empty system, fill with straight Anti-Freeze, put cap on quickly, start and run engine, (pumps).

 

 

 

I'm not saying it will cure all heater core clog issues, but it has worked 90% of the time I've used it.

 

It won't "eat" the core, just the crud that is clogging it. May take some time in doing so, but it won't harm anything to leave it in there, as long as you take steps to insure it won't freeze if outside temps are in that range.

 

One vehicle I can recall at the moment, I left it in there for 3 weeks before flushing system. Lot's o'crud came out of that one.

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Get one of these garden hose repair ends at the hardware store;

 

d5e90d773361d104b52b540f49567288

 

Remove both heater core hoses from the engine, put the hose connector above onto one end and turn the water on slowly, and gradually turn it up. After the water flows clear, switch hoses to reverse flow and repeat. Remember, your cooling system operates at 13 psi, your house water pressure is around 60 or more. So be easy with it.

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wow, that sounds _exactly_ like my 91 loyale. Sitting there, with 2/3rds of the dual row radiator blocked, it will eventually heat up and turn the electric fan on. It then has good heat in the cabin. Once I start driving, it cools off.

 

When the fan kicks on, the gauge is maybe 3/8" from C. While driving, it's half that.

 

It has a new legacy thermostat (online place sent me the wrong one, lol. had to make it smaller to fit), and a new water pump a year or so ago. I flushed everything when I refilled after putting on the new WP.

 

I was eventually going to reverse the hoses going into the core to see if that helps.

 

-Dave

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I was eventually going to reverse the hoses going into the core to see if that helps.

 

-Dave

That's a good, quick way to back flush the heater core, as long as you plan to flush the system before too long. Reverse the hoses, drive a week, flush system, put hoses back to original position.

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:burnout:Well, Got it running warm! It's nice and toasty! I pulled the hoses, back flushed them, than hooked them back up. I than rinsed all the coolant out and filled it with water and a prestone radiator flush. It said to run the car 10 minutes but I ran and errand so about 30 minutes. Once I got home I started to drain it imediatly. I than opened up only one side of the heater core. I turned my compuressor down to 10PSI and started to blow air into the system. Good god you should have seen all the crap blowing out the radiator. I than filled it with more water and repeated that process once again. After that everything flowed very clean. So, I filled with a 50/50 mix. Yup, nice and HOT now! Thank You all for the help and Ideas!!!!

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