» Site Navigation | | » Recent Threads | | | | | | | 12-02-2005, 02:04 PM | #1 | Senior Member Join Date: May 2005 Location: Indianapolis, IN Posts: 228 | Heat at speed, cool air at idle Hello again everyone, I endeavored to fix the heat in my car last night, and it worked! See this thread for details if you want. But now that the Bowden cable properly operates the heater flap (so it shouldn't cause any problems), I notice that even though the car is up to temp the air is cool at idle. Only when I hit the revs does the heat kick in. So, hot air at speed, cool air at idle. Any ideas? This was unexpected. It may be unrelated, but I noticed that I couldn't burp my cooling system without revving the engine last night, either. Thanks in advance guys. | | | 12-02-2005, 02:20 PM | #2 | Senior Member Join Date: Jun 2003 Location: Greenville, SC Posts: 9,356 | Could also be the heater bypass valve located on the firewall. __________________ ...steven BMW CCA #146825 1996 BMW 328ti • 2003 MINI Cooper S • 2016 M235i www.bmwcca.org | | | 12-02-2005, 02:40 PM | #3 | Senior Member Join Date: May 2005 Location: Indianapolis, IN Posts: 228 | When you say "on the firewall" does that mean under the hood up against the wall between the engine and the cab? Or do you mean inside the cab up against the wall in between the engine and the cab? Thanks cali. I found a heater valve for $74.95 at bavauto.com, but is this something I could replace on my own? Do those hoses all have antifreeze in them? | | | 12-02-2005, 02:58 PM | #4 | Senior Member Join Date: Jun 2003 Location: Greenville, SC Posts: 9,356 | It is on the engine side. Don't replace it unless it's bad. Turn on your heat and be sure the engine is at operating temperture. I think there are two hoses going to the valve. Both hoses should be warm. Those hoses would have antifreeze in them. Then the system would need to be bleed again for air. I've never done it, just watched a mechanic do it. __________________ ...steven BMW CCA #146825 1996 BMW 328ti • 2003 MINI Cooper S • 2016 M235i www.bmwcca.org | | | 12-02-2005, 03:04 PM | #5 | Senior Member Join Date: May 2005 Location: Indianapolis, IN Posts: 228 | Thanks Cali, I found the precise diagram for this part ( it's item 5, but you knew that), and I see where it should be in relation to the heater radiator. Now that I'm becoming more comfortable with how these "cars" work I think I can test to see if the two tubes are warm at idle. As you suspect, I suspect they will not be until I rev the engine, and even then the valve will only push hot water for as long as I throttle. But these are only guesses. To bleed the entire system there's a valve on the bottom of the radiator, no? If I catch all of the coolant/antifreeze, can I reuse it after I perform the operation if I use a clean container to catch the coolant mixture? | | | 12-02-2005, 03:06 PM | #6 | Senior Member Join Date: Jun 2003 Location: Greenville, SC Posts: 9,356 | There is a bleed valve or screw on the top of the raditor. You should have water flowing through the valve at idle. And STOP calling me Cali. __________________ ...steven BMW CCA #146825 1996 BMW 328ti • 2003 MINI Cooper S • 2016 M235i www.bmwcca.org | | | 12-02-2005, 03:22 PM | #7 | Senior Member Join Date: May 2005 Location: Indianapolis, IN Posts: 228 | ****! SO sorry about that, man. I feel like a jerk for getting you confused with another member. I know the plastic bleeder screw you're talking about next to the coolant fill cap. Perhaps I can just lift the pump up and out of there (if the tubes are flexible enough) and use a vise to clamp them while I change out the part. Is that what you're thinking? Thanks 1996 328ti | | | 12-02-2005, 04:16 PM | #8 | aka Stabby Join Date: Nov 2004 Location: Mead, CO Posts: 5,336 | Quote: Originally Posted by Severian ****! SO sorry about that, man. I feel like a jerk for getting you confused with another member. I know the plastic bleeder screw you're talking about next to the coolant fill cap. Perhaps I can just lift the pump up and out of there (if the tubes are flexible enough) and use a vise to clamp them while I change out the part. Is that what you're thinking? Thanks 1996 328ti | LOL ... i'm so good, i answer questions when i'm not even on! cali-ti = eric, 1996 328ti = steven __________________ 1996 318ti, California package, 267k miles current mods: bilstein sports, bavauto springs, e30 m3 LCABs, solid metal ball joints, bavauto RSMs w/reinforcements, e30 3.73 LSD & halfshafts, supersprint cat-back exhaust, turner rear sway bar reinforcements, IE poly subframe & RTABs + camber/toe kits, powdercoated e36 32x front calipers, sport mirrors, H&R 28mmF/19mmR sway bars, x-brace, auto solutions SSK w/poly bushing upgrade, BMW CD43 head unit, DICE HD Radio w/iPod integration and "stealth" HD antenna, staggered style 68s, orange electronic TPMS, leather arm rest, JT Designs metal undertray acquired and awaiting install: heated seat kit, cali top switch relo, lumbar support kit, park distance control kit, heated washer nozzle kit, m-coupe rear subframe, trailing arms, differential, and halfshafts, m-coupe front/rear brakes with master cylinder, under hood light kit, mud flaps, rear sun blind, auto-dimming rear view mirror, tilt steering wheel retrofit, apexcone 5000K HIDs with 55W ballasts 2002 X5 4.4 Sport Package, 53.5k miles Current Mods: e46 m3 steering wheel | | | 12-02-2005, 09:08 PM | #9 | Senior Member Join Date: Aug 2004 Location: state college, pa Posts: 3,431 | Quote: Originally Posted by 1996 328ti And STOP calling me Cali. | At least he didn't call you Shirley. __________________ I scream, you scream, we all scream for ZOMBIES. | | | 12-03-2005, 02:20 AM | #10 | Senior Member Join Date: Jun 2003 Location: Greenville, SC Posts: 9,356 | Quote: Originally Posted by Severian I know the plastic bleeder screw you're talking about next to the coolant fill cap. Perhaps I can just lift the pump up and out of there (if the tubes are flexible enough) and use a vise to clamp them while I change out the part. Is that what you're thinking? | It's not difficult to open the bleed screw. But be sure it's a bad valve first. Don't change perfectly working parts for another perfectly working part. __________________ ...steven BMW CCA #146825 1996 BMW 328ti • 2003 MINI Cooper S • 2016 M235i www.bmwcca.org | | | 02-16-2006, 01:33 PM | #11 | Senior Member Join Date: May 2005 Location: Indianapolis, IN Posts: 228 | An update (and solution) to our quirky problem; a new Water Pump. Recently our engine started making a slightly alarming metal-on-metal style noise...it was running louder than it should have. Our mechanic said the water pump was on the verge of going bad, and it was making the loud noise. With the new water pump we have heat all the time (even at idle). WoOt! | | | 02-21-2008, 02:18 PM | #12 | Senior Member Join Date: May 2005 Location: Indianapolis, IN Posts: 228 | Update: We no longer have hot air at idle. On days when it's really cold I just turn off the blower since it starts blowing cold air. I'm going to have a new Water Valve put in. http://www.realoem.com/bmw/showparts...02&hg=64&fg=18 | | | 02-21-2008, 02:35 PM | #13 | Senior Member Join Date: Jul 2007 Location: SW Florida Posts: 4,275 | so, your car worked fine for the past 2 years with the new water pump...then the heat went out recently? i also have a problem like this...the heat problem i mean. post again if the water valve works for ya. thanks __________________ Sean 1995 Active | | | 02-21-2008, 03:04 PM | #14 | Senior Member Join Date: May 2005 Location: Indianapolis, IN Posts: 228 | I will indeed. The problem is not an overnight development...I've been dealing with it by revving the engine at stop lights. I am tired of this though, and I would like my car to blow hot air while at idle RPMs. My wife would also like it; she's ready to disown the car. Such animosity towards a car into which I've poured so much work cannot go unchecked! So far I've performed (or had performed) the following on this car: * Replaced Thermostat * Burped * Fixed bowden cable problem * Replaced water pump All fixes resulted in improvement of some kind. This is sort of the final frontier for heat issues I think. | | | 02-21-2008, 03:12 PM | #15 | Senior Member Join Date: Jul 2007 Location: SW Florida Posts: 4,275 | good luck __________________ Sean 1995 Active | | | | | Currently Active Users Viewing This Thread: 1 (0 members and 1 guests) | | Posting Rules | You may not post new threads You may not post replies You may not post attachments You may not edit your posts HTML code is Off | | | |