Author Topic: Wintertime heat (Read 4095 times)

JHZR2 · « **on:** December 17, 2007, 10:48:49 AM »

Hello,

Just curious of two things... how poorly does you 318's heat work, and how fast does the engine loose heat after shutdown in the winter.

My heat has never worked well. No real blend at all at half-heat. Minimal heat at 3/4. Doesnt really work to warm the cabin at all unless I set the dial at full heat, then it works OK at best.

I replaced the heater core and heating control, anti-freeze, etc. The cooling system is very clean. No dice... no luck getting hot air from the climate system with the dial set at anything but full heat. The blend door works properly, BTW.

I dont really think that the car makes enough heat to sustain itself. My car's temperature is never beyond a needle-width past the 1/4 line. This is the case even with highway use. I'd assume that if it was a stuck open thermostat, the engine would take forever to heat up, but with highway use, etc., it would eventually get up to the correct temperature, right? The interesting thing is that whether in the summer or winter, if shutting the car off, the needle will very quickly start to drop. Most cars hold temperature for a while after shutdown (even in the winter) because of heatsoak, etc., but on my 318i, within 5 minutes of being off, the needle will have started to move down. The engine does have a large oil sump, pretty big radiator, etc., so I assume that will have a substantial effect.

Can anyone else comment on their heat and engine's ability to hold its heat in?

Thanks!

JMH

Wise Old Dog · « **Reply #1 on:** December 17, 2007, 10:56:07 AM »

Most of the 318's here will see about a 12 o clock temp. The temp sensor for the guage is located in the head, which is aluminum. Aluminum disapates heat very quickly. You need to check your thermostat and make sure you have the correct temp.

tjts1 · « **Reply #2 on:** December 17, 2007, 11:15:32 AM »

You need to replace the thermostat. You temp gauge should get to the 1/2 way mark within a few minutes of starting summer or winter. I used this car when It was 10f outside and I had some heat after 3 minutes and it was nice and toasty after 10 minutes of starting. This has nothing do to with the size of the engine or the material used. With a good thermostat it should be able to heat up the cabin well below freezing. It helps to use the recirculate button to retain heat.

JHZR2 · « **Reply #3 on:** December 17, 2007, 11:16:12 AM »

is there a good DIY on thermostat replacement on this car???

Thanks!

JMH

tjts1 · « **Reply #4 on:** December 17, 2007, 11:20:45 AM »

http://www.esatclear.ie/~bpurcell/318ismaintenance.html#thermostat

http://zoso.no-ip.org/318i-thermostat.html
Good luck.

gearheadE30 · « **Reply #5 on:** December 17, 2007, 04:20:10 PM »

My heat also doesn't blend well, but it will get to 3/8ths in the time it takes me to get to school (10 mins). It does take the car awhile to heat up the interior, though.

JHZR2 · « **Reply #6 on:** December 18, 2007, 08:41:37 AM »

in reality mine isnt much below 3/8ths... maybe a needle width below 3/8, given that Im a needle width above the first tickmark out of the blow (I assume that is 1/4). However, it still concerns me that I dont get past that point even with longer driving.

That said, has anyone correlated the major tickmarks on the temperature gauge for operating temperature? I know that flaky grounds and electrical gremlins can cause the gauges to not read right, but theoretically the gauge shows according to some resistance provided or signal sent from a temperature sender, where the resistance or signal behavior with respect to temperature must be known. Same for the gauge, its position correlates to some signal or resistance. Does anyone know what the center or other tick marks actually should indicate roughly???

Thanks,

JMH

JHZR2 · « **Reply #7 on:** December 20, 2007, 01:31:21 PM »

Well an 88C Wahler thermostat puts me about a needle width below the halfway mark, with a much quicker heatup. Still doesnt have the best wintertime heat, but this is a small engine that breathes well, so I suppose there isnt really as much heat load on the (potentially oversized) cooling system. The fact that it has a larger than average oil sump aids in cooling as well.

But things are good. I suppose the first main tick mark corresponds to ~80C, and the halfway corresponds to 92C (there is an OE 92C thermostat also available...).

Thanks,

JMH

tjts1 · « **Reply #8 on:** December 21, 2007, 11:59:27 PM »

I remember reading that the "water valve" (#16 in second pic and #7 in third pic) can become stuck closed. I think its some sort of thermostat instead of a valve.
http://www.realoem.com/bmw/partgrp.do?model=AJ93&mospid=47318&hg=64&fg=15

HaNasich · « **Reply #9 on:** January 06, 2008, 08:51:17 AM »

indeed, on my car heating is very poor.
temp gauge usually sits at the 1/2 stand after the car has warmed up, but than the air coming out of the vents is a bit warmer but nothing that really heats the car up.
if i compare it to my other to Mitsaubishi's - when u turn heating on there u can touch the vents coz the air blowing out is so hot....

Ron.

jrobie79 · « **Reply #10 on:** January 06, 2008, 12:04:45 PM »

i can get my car parts for a huge discount cause my dads buddy runs the shop down the street. i asked if they had oem thermostats for the m42 and he said it was a 176 degree one, which translates to 80 degress celcius, should i be asking for one that is 88?