Help no heat

[FastWoman]

Wow, 22 deg... Toasty!

I agree with the tech: "That ain't possible." Where there's fire, there's heat, even ignoring the friction. By any chance, do you have an oil cooler on your car? That could be bleeding off your heat.

[Neumeier]

My '78 had the same problem. In the engine compartment on the right hand side (to the left of the battery, about half way down), are some vacuum lines entering the firewall. Check there first and work your way to the right fender. In my case, the problem was right at the firewall. While the vacuum lines under the dash can be a problem too, they tend to hold up much better.

[theramz]

Z cars are cold blooded. You could try the cardbourd block and or remove the fan completely.

[FastWoman]

Z cars are cold blooded. You could try the cardbourd block and or remove the fan completely.

... or move to a warmer climate!

[conedodger]

Heater control valve? Behind the glove box, on the inside of the firewall. Sometimes pisses all over your carpet when it is bad...

[IdahoKidd]

No, the selector works fine and it regulates what heat is there. The engine itself isn't making heat. I've tried three thermostats from used motors I have setting in the shop. All open and close in a pan of heated water. I am going to go buy a new one today and give it a shot. As I mentioned above, I can pull the radiator cap and put my finger in the water after running for two hours. I bought a candy thermometer to get specific numbers and have it scheduled for a thermal imaging at the local Toyota shop. The motor is a rebuild with about 20k miles on it. It runs perfect, isn't overfueling. The clutch fan rotates freely which tells me it isn't locked up. It is the traveling with the piece of cardboard covering the radiator and still not making heat that is the bizarre thing as it should act like a manual thermostat of sorts. 7 degrees outside this morning, heat is sort of an issue.

[FastWoman]

SEVEN DEGREES?!

I think you're losing all your heat directly from the engine block to the cold air. I know this is an awful suggestion, but is there any way you can wrap the engine in insulation, at least during the winter? There's a somewhat expensive material that's a bit like stiff, silvery bubble wrap. You can get it at Lowes or Home Depot. We have it around our boiler, which runs at 180 deg. It's thin, it wouldn't mess up your engine compartment, and it would stand up to the heat just fine. Maybe you could wrap over the top of the valve cover, down around the right side, and under the oil pan (staying away from the exhaust). You could cut out for spark plugs and the engine mount, and you could probably find someplace to bolt down a clamp on each end.

Hey, you might be able to save back just enough heat if you insulate only the bottom of your engine. That way it wouldn't look quite as goofy.

Just a thought...

[IdahoKidd]

200 degree thermostat makes 160 coolant temp. Heat loss through heater hose and to heater core drops heater core temp to 90. Air temp at defrosters is 62. Cabin temp is 46 degrees. Guess I am driving the back up car for a while.

[260zCaliCar]

Being in Los Angeles, (where we are going to get a bit of rain today and its all over the news) I can't imagine this kind of cold... But based on what Fastwoman said above, sounds like you would do really well using the insulation she suggested on all of the heater hoses and ventilation tubes as well. I'm not questioning you even for a second, but it's hard to believe that the coolant drops 70 degrees in the short distance to the heater core. Again, I'm not questioning you, I just don't have the experience with that kind of cold.

[IdahoKidd]

Coolant drop is only from the engine block to the heater core. The heater core is essentially a miniture radiator and the systems sheds heat all along the way. What I don't know now is if the water pump is not pushing enough volume to prevent the heat loss or just what. The block water should be 200 with the 200 thermostat and it simply isn't. I am doing some homework now on how the water bypass system inside the pump works. Heated water is leaving the block prematurely I think and never letting it get completely hot. With all my heart I don't want to work on it today (and won't). Tomorrow the high is 15, the low -1. I've already dug out my "clean clothes car". At least there isn't any snow. yet.

[Neumeier]

Thought I'd add a reality check. I have been driving my '78 the last four days with weather from -15 F to -5 F. The heater works just fine, so all of this stuff about the engine not developing heat because it is radiating it away does not make any sense. I'm not sure what thermostat is in my car, but it is probably around 190 F since the care has always been in Montana.

Sorry I can't offer any technical input. Seems that the thermostat is at fault to me, but you have checked them in a pot of water to make sure they open - a good idea!

[IdahoKidd]

Yeah I know it should work, hell, one the Z's I bought this spring has a ski rack on it. Can't imagine going skiing in a car with no heater. (did it once but that is a very different story..........)

It looks like you guys are getting it worse than we did. Just cold and windy here.