OZ2002 wrote:

I'd like some opinions on this one. I live in Kansas where summer temps are often above 100 and winter temps can hover around 0. Problem is the heater runs quite cold in winter, particularly during highway driving or with temps below about 30. I think the radiator, heater core, valve and hoses are all good. I'm not sure which thermostat I have, but its a California car. Should I switch between the summer and winter thermostats to accommodate seasonal temps? Seems like a hassle, but I don't want to chance overheating the engine during the summer. Thanks.

There isn't much difference between running a 160 deg thermostat and a 180 in the summer IF your cooling system is working well! Being typically you're car in 90+F weather is running 190-200 water temps anyways.

In the winter there is a large difference between a 160 and 180, but if you're driving your 2002 outside in 0F days, why not stick some cardboard in front of the radiator to curtail some of the cold air coming in? Most midwesterners do that for just about any older car. It makes the difference between toasty toes and freezing ones!

Use a 180 deg F thermostat unless you're having major problems with heat in the summer and if you are overheating a thermostat isn't going to solve the problem. Look for blocked radiators, mistuned or tired out engine, leaking hoses etc.

WH

"... but if you're driving your 2002 outside in 0F days, why not stick some cardboard in front of the radiator to curtail some of the cold air coming in? Most midwesterners do that for just about any older car."

A slightly more elegant way (and a lot less noticeable) is to remove the two upper radiator mounting bolts and insert a washer between the bolt and the mounting point on the body. That'll give you just a little space--enough to insert an offset litho plate in front of the radiator. Offset plates are very thin, rigid aluminum and one 11x17 one will cover just enough radiator to make the car run nice and warm if it didn't before. Check with a print shop, they'll most likely give you a couple of old ones. Bend one end over in a U shape to hook over the radiator support, and you're in business

Best of all, they don't show and are easily removable.

mike
_________________
'69 Nevada sunroof--"Wolfgang"--bought new
'73 Sahara sunroof-- "Ludwig"--mine since '78
'87 eta E30 coupe--"Johannes"
+ Fiat Topolini (Benito & Luigi), Renault 4CVs (Anatole, Lucky Pierre, Brigette)...
and Kermit, the Bugeye Sprite

WH wrote:

OZ2002 wrote: I'd like some opinions on this one. I live in Kansas where summer temps are often above 100 and winter temps can hover around 0. Problem is the heater runs quite cold in winter, particularly during highway driving or with temps below about 30. I think the radiator, heater core, valve and hoses are all good. I'm not sure which thermostat I have, but its a California car. Should I switch between the summer and winter thermostats to accommodate seasonal temps? Seems like a hassle, but I don't want to chance overheating the engine during the summer. Thanks. There isn't much difference between running a 160 deg thermostat and a 180 in the summer IF your cooling system is working well! Being typically you're car in 90+F weather is running 190-200 water temps anyways. In the winter there is a large difference between a 160 and 180, but if you're driving your 2002 outside in 0F days, why not stick some cardboard in front of the radiator to curtail some of the cold air coming in? Most midwesterners do that for just about any older car. It makes the difference between toasty toes and freezing ones! Use a 180 deg F thermostat unless you're having major problems with heat in the summer and if you are overheating a thermostat isn't going to solve the problem. Look for blocked radiators, mistuned or tired out engine, leaking hoses etc. WH

Last I checked. The thermostat maintains the water temp inside the engine. Since the water temp on the gauge is measured by the water inside the termostatic loop; which the heater core is in that same loop. It doesn't matter if he's got the mother of all radiators on it. Or cardboard covering the whole thing. If the gauge shows 160 degree water is in the engine/heater core loop.. and he's not getting any heat. It's a valve/heater core issue. Has nothing to do with the radiator. Either the water is hot or it's not. Now covering the radiator may decrease the time from cold to warm but won't change the amount of heat that the core can put out.

oldguy wrote:

Last I checked. The thermostat maintains the water temp inside the engine. Since the water temp on the gauge is measured by the water inside the termostatic loop; which the heater core is in that same loop. It doesn't matter if he's got the mother of all radiators on it. Or cardboard covering the whole thing. If the gauge shows 160 degree water is in the engine/heater core loop.. and he's not getting any heat. It's a valve/heater core issue. Has nothing to do with the radiator. Either the water is hot or it's not. Now covering the radiator may decrease the time from cold to warm but won't change the amount of heat that the core can put out.

I would agree that the heat given off from the heater core is dependent upon the cooling system feeding it. If you have a radiator that is too efficient (super large cooling area or a humongous fan, the radiator may shed too much heat and not reach the desired operating temp. One obvious means of modulating the heat is be controlling the flow of coolant in the system (thermostat). Another means of modulating the heat is by restricting the flow of air to the radiator. This has been done for years by the use of shutters.

I grew up with a lot of old cars and farm equipment, some of which was repaired by a blacksmith. I cannot think of a specific example at the moment(maybe Packard or REO, but I know we would make both the engine and cabin warm up quicker and remain hotter with shutters. In effect, the shutters made the radiator and the entire cooling system less effective. My memory is dim, but I am certain there were a few cars that did not have a thermostat at all, relying entirely on the shutters.

oldguy wrote:

Last I checked. The thermostat maintains the water temp inside the engine. Since the water temp on the gauge is measured by the water inside the termostatic loop; which the heater core is in that same loop. It doesn't matter if he's got the mother of all radiators on it. Or cardboard covering the whole thing. If the gauge shows 160 degree water is in the engine/heater core loop.. and he's not getting any heat. It's a valve/heater core issue. Has nothing to do with the radiator. Either the water is hot or it's not. Now covering the radiator may decrease the time from cold to warm but won't change the amount of heat that the core can put out.

I'm not sure what you're point is, of course the engine water and heater core water are the same! 160 deg water in an engine when it's 0F outside is a sure way NOT TO HAVE HEAT at all in a 2002. These cars have poor heating capability, so anything you do to improve it (say run a 180F thermostat) will improve heating in the car drastically. In the same way blocking part of the radiator off in the winter reduces the efficiency of the radiator when driving allowing the engine to run warmer. This can be very important in very cold conditions (0F or even colder). This helps the engine to maintain operating temperature when driving being it might actually reach water temps OVER the opening temperature of the thermostat, increasing the heat making capability inside the car.

I for one have frozen in the midwest winters in -30F weather (wind chill -50+F) in an old car. I can say even with a 180F thermostat in my old BMW, without blocking off part of the radiator, my car would never get to operating temperature and maintain it when moving especially at highway speeds. The car would not produce much heat or feel warm inside until I partially or nearly fully blocked off air access to the radiator, simply because the system was too efficient at cooling the car at those temperatures.

WH
Midwesterner for 28 years till I got smart and moved out west.