low heater output - cold weather operations

[duluthsvo]

Cold weather has hit Northern Minnesota and I'm curious if anyone has figured out an effective way to get more heat out of the stock HVAC circuit (other then blocked radiator, high idle kit, switch from the 190F thermostats to the 210F, etc.). Discharge temperature on defrost seems to cool and the fan on high is inadequate at best. Any input/suggestions would be appreciated. Thanks DuluthSVO

Just as an FYI..Coolant circuit in the truck is fresh and clean as I just installed my new motor/radiator 3 months ago.

[Kennedy]

I always ran the 195

[JTodd]

Good Question. What is the normal warm up time for a 6.5? I plugged mine in over night (temp=15*, started very easy, so I am confident it is working), grill is covered and after driving for about 40 minutes the temp never got above 180* and it creeped to that. Is this normal? Are there any tips on getting it up to temperature sooner. Running the morning car pool gets tough on the little ones.

[Gapper_ca]

Well know all about cold weather. we had -26 C or - 15 f the other day. truck pluged in for 4 hrs, any longer does not help. starts good. letting idle for 5 to 10 minutes engine temp is starting to rise, drive about 2 miles at bout 40 to 50 then engine is at full running temp. 195 t-stats, front grill cover. even when it gets to -40 which it does lots in january no problems with heat at all. but if front was not closed in ???? will be instaling a magnetic oil pan heater again , seems to start even better and warm up faster. at -40 if i let it idel for duration of command start cycle it will be about 170 or so, windows fully defrosted. drivers side is slow but there was a upgrade from GMC...

[Marty Lau]

I have had that trouble at bit in the sub-zero temps here in MT and winter front I have fron Lund snaps in the grill makes big difference. They snap into place and if it start to warm up take a couple the covers out.

[KallyI]

I live in the "Great White North", and have never had a problem with too little heat in the winter time, even down to -45

[hayesash]

After doing the 97 cooling mods I had a lack of heat problem. Turned out to be one of the new GM thermostats. It wouldn't close all the way. Had to look real close to see the gap.

Pat

[alman]

I agree with the thermostat Being stuck open,Just a little bit will cause a problem, This Happend to me and drove me NUTTS !!!

[Dihrdbowti]

Could it be a bad heater core?? I had an issue like this with an old Camaro. Went through the whole cooling system and for the hell of it changed out the heater core. Plenty of heat after that.

[catmandoo]

man my 92 has more heat then i can stand.i usually run with the fan on low or start backing the temp down,this thing i believe could melt your shoes if you didn't watch it.and my temp gauge never gets over 165.my timer is set for 2 to 21/2 hours before i hit the road and i usually start and let run for 5-10 minutes or til the windows are defrosted.and i don't use a winter front,did on my old 84 and it needed it but this thing doesn't.

[BuffaloGuy]

I'd check the heater vent levers on the left side of the big main heater duct that comes down near the gas pedal. They're hard to see, but if you lay down with your head right next to the gas pedal and look up you will see them. You might need a flashlight.

There are 2 levers with springs. It's quite a combobulation and I've had trouble with mine several times before.

The best thing to do is to turn the key on and, while looking at the levers, change your heater vent settings and make sure they are doing what they should.

If they have fallen off or you are missing the springs the doors may not be opening and letting the heat in. It's a cheap fix but it's a real pain in the neck to work in the little space.

Mine kept falling off the axle that is connected to the vent. I finally gobbed a bunch of hard setting gasket sealer on them and pushed them on. (That was a whole lot harder than it sounds)No troubles now.

The odd thing I noticed is that after I did the repair my display panel that shows where the vents are set to blow air to started to work right.

Before it would flash at times and then eventually disappear. Now it never flashes and works just fine. It had been flashing for the last 150,000 miles!

There must be a sensor somewhere that could tell all was not working as it was supposed to down there.

[markrinker]

I have found a quick easy way to flush heater cores is to disconnect the heater hoses, attach to pressure washer wand, and carefully flush with soapy, then clear water. Lots of rust and scale can be removed. I have improved heater operation on many old vehicles with this same method, rather than removing non-leaking cores.

[chickenhunterbob]

My vote also to have the thermostat(s) or heater core checked. I had an old ford half ton a while back that was severly lacking for heat, I had a chemical flush of the cooling system to clean out all the crud in rad, heater core, etc. and viola. Not sure what type of chemical they use, bit it sure worked. I had it done at a place that specializes in cooling systems.

My 1994 chev 6.5 has also more heat than I can stand, usually have the arrows on the dash set a notch or two above centre and that's lots for the coldest days.

Also, I don't use a winter front. I asked the previous owner when I bought the truck and he said he never used one, his dealer mechanic said not necessary. I found this to be true in my case at least. About 2 - 3 km slow driving after the fast idle shut down and it's right up to normal operating temp despite the ambient temp.

Bob

[curmudge1]

In my case, it was the heater core. Does the dash temp gauge indicate ~ 190*F, or better? Mine always runs about that, regardless of exterior temp. If the temp gauge indicates low, then I'd look at the thermostat. It's always possible to have more than one problem, too.