lack of temp

[86c20]

i run about a 60 40 ratio. but the problem with was there before i replace everything and the new coolent

[86c20]

i run a 60 40 mix as i do take the truck up to norther maine in feb most years to see my mom and it is nothing for it to be -30 never had a problem before tho.

and the heat problem was before i swaped everything for new coolent was last thing

[hatzie]

Mores' law doesn't apply here. It's a kind of bathtub curve.
0:100 is obviously +32F and adding more Prestone brings the temp down... to a point.

50:50 is good to -35F. I've never seen ice crystals the several times I've seen temps at -40 using 50:50 mix so anything more is pretty much overkill unless you're above the 47th parallel or hell just froze over...

60:40, what I call the devils' icebox mix, is good to -65F. It should still give you OK heat. This is pretty close to the bottom of the curve. There are places above the 46th parallel in the middle states that get this cold. I've been to Grand Forks ND and Crookston MN in January and seen -45F but they were closing schools too so it's not business as usual there. New England isn't getting that cold on a regular basis even in Stewartstown and Pittsburg NH or Caribou and Presque Isle ME. We're too close to the North Atlantic. The top of Mt Washington doesn't count. This mix will actually begin to inhibit your heat transfer somewhat but not to the degree you're seeing.

70:30 is actually back up to -55F

And 100% Prestone is slush at +10F so the actual start of freeze is above that... 100% also flows so badly that it's not any good in the summer either.

[hatzie]

First thing I'd look at is the heater box blend door seal.
Are you leaking air around the kick panel vent flaps or the heater box intake on the passenger kick panel? Rust holes in the plenum under the wipers?
Your vent temp at 120F should warm up the cab unless you are leaking in cold air.

I'd look at the fan clutch and change the thermostat.
The next thing I'd look into is moving the heater return from the radiator to the water pump like the earlier trucks.
A 350 or 305 with a massive radiator should have no trouble driving you right out of the cab using the heater in the dead of winter. I've had several of them do just that.

[chengny]

The engine is generating the same amount of heat it always did. Those BTU's are transferred through the cylinder walls/cylinder head passages to the coolant.

There are only two heat exchangers in the system that can remove BTU's from the coolant. One is the heater core and the other is the radiator. The original complaint was a lack of heat from the heater core so it would be safe to assume that the BTU's are not being removed by that heat exchanger.

That leaves the radiator - as the only place where the heat generated by the engine can be removed from the coolant. The radiator will only remove heat from the coolant system if there is hot coolant flowing through it.

The rate of coolant flow through the radiator is dependent on the degree of opening of the thermostat (or what leaks by the thermostat).

The proper procedure to confirm proper t-stat sealing is to pull the upper radiator hose from the radiator inlet tank and visually confirm a no-flow condition upon an initial cold start.

With the hose off the radiator inlet neck and pointing down towards the ground, there should be virtually no coolant coming out of it.

If there is any more flow than what can pass through the little vent hole in the t-stat disc, something is allowing it to exit the engine. Either the stat is not closed or there is leakage between the joint formed by the intake manifold, the t-stat flange and the water outlet.

If the idea of running the engine with the radiator inlet hose removed is an issue, try blocking the hose. Use a clamp and two blocks of wood to squeeze the hose shut and let the engine run. Observe whether the coolant temperature rises faster than it does with the hose not clamped closed.

It should not be necessary to block off air flow through the radiator to maintain proper operating temperature of the engine coolant. It will only cool what is available to it.

[86c20]

i have checked the flow when cold and there is less then you think there would be.

yes the complant is not enough heat but the hole motor is cool. and i agree that it should not be necessary to get the motor hot so i am still lost at this point. tomorrow night i am going to pull it back in the shop i use and see what i can find and start from the top and work every spot. dont know what else to do are this point

[donut]

Thing is, if the engine is actually running that cool, then the oil won't cook off the nasties and you'll have bigger problems down the line.

The only reason I covered my rad was to try to put some heat into it. I had 2 temp gauges. 1 either side of the thermostat, so I could "see" it functioning. My engine would produce heat, plenty out of the heater ducts. But radiator had plenty of time to cool between cycles.

This was after I did the floor covering, fixed the blend door seal. Patched the swiss cheese squirrel cage cover (underside of this cover in the engine compartment was rotted out and not visible until I pulled it off.)

[86c20]

well no work done tonight. will be on it in the am tho.

now can some one tell me what the diff in tstat letters are? the one in my truck is a 195b i think and the one in my dads 95 g30hd is a 195a. now he has a rad that is even bigger then the one in my truck and he gets alot of heat. plus his seems to cycle the tstat where mine does not???? or am i off in the wrong way all together? just running things down and if nothing else want to know better.

thanks guys