Engine warm-up FAIL

[wdb]

Originally Posted by Old Mechanic

I used to pull the electrical connection off the ac compressor to keep it from running in the winter.

Do you still do that? I've heard stories about AC seals and whatnot needing to see some activity over the winter months to keep from drying out. I run mine every now and then just for that reason. Usually just turn on the defrost to make the AC run. Fortunately my vehicles have a separate switch for AC, so even if it turns on when defrost is selected, I can turn it off again.

[user removed]

It was below 20 when I pulled out of the garage, middle of the temp gauge in 1.3 miles, less than 2 minutes. Got to love the new thermostat. I actually used fresh air, full heat (temperature at max) and no fan, dash and floor, and it was comfortable, but I do wear clothing to protect me if the 23 year old car craps out.

Recirculate low fan was even warmer but I hate to run the fan unless i have no option.

I did not move the heater temp selector until the temperature gauge was in the middle.

The Sentra has an AC button, so I don't have to disconnect the compressor like I had to on both of my Fords (both sold).

regards
mech

[Striker2237]

Well issue I have with heat is 3 fold, 180 degree T-stat, high volume water pump, heavy duty cooling (the radiator is like 3 inches taller/wider and almost 2x as thick plus a bunch of other coolers for the other things like the diffs and oil and PS, trans cooler is bigger than the rad in my friends 05 civic lol!) and all this leads to almost comical overcooling in winter

[Cobb]

Ohhhhh....... I thought you still had the ford festiva. Yeah, I love my 20 year old suzuki sidekick for the same reason. Its making HOT heat in a manner of minutes/ miles in the coldest of weather VA has to offer long before the temp meter even registers. Ive concluded the sensor is on the other side of the t stat so it only registers when it opens.

My insight takes a good 12 miles before the heat starts to rolling out the vents in it.

I was using my insight for my reference as I thought we were talking about new or late model cars.

Originally Posted by Old Mechanic

I do wear clothing to protect me if the 23 year old car craps out.

[user removed]

I've found the warm up times to be very consistent, fastest was the 98 Mercedes SLK230 in half a mile, slowest I don't remember. There is an overpass to Busch Gardens about 1.5 miles east of my house and every car I have owned would be at operating temp, with plenty of heat by the time I reached that overpass. If I leave the temperature control on max hot, which is useless with a cold engine, add another half a mile to reach full operating temperature.

Before I replaced the thermostat in the Sentra, which was stuck wide open, it took 6 miles to reach the same temperature.

Now, if you are using engine off coasting, and it is extremely cold outside then I could see the coolisng system temp dropping below thermostat opening point and I expereinced that first hand when the fan belt (also water pump) broke on my 76 Z car. I used engine off coasting, which spun the clutch fan, with airflow, and turned the water pump.After 10 miles the temperature was below the normal operating range, even with no fan belt to drive the pump or turn the fan.

Bottom line, if your thermostat is 10 years old and your car takes a long time to warm up andyou are not using engine off coasting then you should check your thermostat.
It requires no tools.

Start the engine and keep you hand on the top (or exit) cooling hose. It will not warmup much at all until the stat opens, then it will become too hot for you to hold your hand on it very quickly. Thats a good thermostat. If it starts to warm upbut takesa long time to get hot, or does not get very hot at all, you have a bad thermostat.

In very cold temperatures, if your car will allow it, use recirculate and max hot settings with lower fan speeds, the same process to get the best cooling with ac in the summer.
It should be easy to understand why it will work much better to reheat the same air repeatedly, versus trying to get -20 degree air to 120 degrees in a single pass over the heater core, in many cases through a cowl screen that is blocked off from any air flow by ice or snow.

If you can't get heat and everything previously suggested fails to help, then block off air flow to the radiator, but remember the heater core is not apart of the radiator circuit so when you set the temperature on a cold engine it can take much longer to get it warm and in extreeme cold the heater core itself may have more capacity that the engine needs to stay too cold.

regards
mech

[Cobb]

Its a 2010 insight and Ive done all that. Ive just concluded hybrids have hybrid heater and cooling systems. You know, half warm in the winter, half cool in the summer. When it comes to either extreme I park the hybrid and drive the zuke.

Ive taken the Busch gardens exit before and the ones before and after it. Theres one that goes over a rail road crossing. My insight when on the tanabe df springs will bottom out on the tracks making sparks. Visited Christmas town one year.

[user removed]

You must be talking about the Lee Hall exit, first one east of the Busch Gardens exit (about 3 miles east). Let me know next time you're in the Neighborhood, the meal is on me.

regards
mech

[user removed]

Originally Posted by Cobb

Ohhhhh....... I thought you still had the ford festiva. Yeah, I love my 20 year old suzuki sidekick for the same reason. Its making HOT heat in a manner of minutes/ miles in the coldest of weather VA has to offer long before the temp meter even registers. Ive concluded the sensor is on the other side of the t stat so it only registers when it opens.

My insight takes a good 12 miles before the heat starts to rolling out the vents in it.

I was using my insight for my reference as I thought we were talking about new or late model cars.

The Fiesta did not have a temperature gauge, but you could telll how warm it was by the idle speed. I did have an overheating idiot light.

regards
mech

[jamesqf]

Originally Posted by Old Mechanic

I've found the warm up times to be very consistent, fastest was the 98 Mercedes SLK230 in half a mile...

You have to remember two things. First, in coastal Virginia you don't really have much in the way of actual cold, just what many of us would think of as light sweater weather.

Second, you need to remember that the heat is created by burning fuel. Your Mecedes, for instance, has a 21/29 mpg rating (per Google). On the mostly level stretch I drive my Insight towards town on, once I get up to speed I'm cruising at close to 100 mpg. Not much fuel burned = not much heat produced.

[Occasionally6]

Re. AC:

The AC doesn't just cool the air passing through the evaporator, it heats the air passing through the condenser. That may help a little in warming the radiator (at least) and with the same CoP - heat transferred/compressor work - as it does on the cooling side.