Problem with my heat!!

[bimmer95]

If the heater blows hot air when you rev the motor to ~2500RPM, but then goes luke warm at idle, you definitely still have air in the cooling system. Most novice BMW DIYers top off the coolant reservoir and think their done bleeding the system, that is vastly incorrect. You need to start with the car cold and have someone hold the RPMs to ~3000 while filling the system to properly flush any air out. Here's my quick write up on the subject, http://www.understeer.com/faq.shtml#coolingbleed

[Severian]

Ahh! Okay, I'm attempting to stop the parts order right now. When I bled the system I never had assistance, so I will try this prior to buying anything.

[Will'sBimmer]

elchicano318ti I just checked my temp gauge is in the middle, it blows out warm air but not as hot as before. Where is heater valve control located? Do you got a pic to show me? thanks


Yes my temp holds rock solid in the middle. I lose heat when at lower RPMs...I always get intense heat at 3,000+ RPMs. I have placed an order for a water valve (#5 in the diagram):
http://www.realoem.com/bmw/showparts...02&hg=64&fg=18


it is #5 in the diagram. It is located left of the fuse box, close to the firewall. you will see it is kinda hidden but once you start to look back there you will see the top of the pump, it will metal and round.

[Severian]

Originally Posted by Severian

Ahh! Okay, I'm attempting to stop the parts order right now. When I bled the system I never had assistance, so I will try this prior to buying anything.

I followed these instructions over the weekend:

How do I bleed my BMW's cooling system?
It really helps to have a friend lend a hand by sitting in the car revving the motor and keeping an eye on the temp gauge. Start off by removing the coolant reservoir cap and the plastic bleeder screw right next to it. Fill the coolant reservoir with a 50/50 mix of coolant and distilled water. Have your friend start the car, turn on the heater to full hot on the vent position and rev the motor to about 2500 RPM, if the temp gauge goes past the 12 o'clock position, shut the motor off, let it cool down and start over again. Watch the coolant reservoir, as the engine warms up the coolant level should drop, refill as the coolant is sucked out of the reservoir. Watch the bleeder screw hole also, when coolant with no air bubbles begins to overflow then you're almost done. It's a good idea to have some paper towels handy to mop up any overflow. Screw the bleeder screw back in (be careful to not break the plastic screw) and continue to rev the motor, you should see a continuous stream of coolant spraying in to the reservoir from the small hole at the top. Continue letting that spray in to the reservoir while your friend revs the motor for a couple of minutes, until the gauge hits the 12 o'clock mark, to ensure any remaining air is gone. If the heater is blowing hot air when you're revving the motor AND when the engine is at idle then your cooling system is properly bled. If your vents are blowing cool air at idle then you still have air in the system, try revving the motor more and/or squeeze the radiator hoses to help dislodge any trapped air. Once your system is fully bled, top off the reservoir and replace the cap. Check the coolant level in a day or two and top off as needed.

I followed the process as best I could. I ran into a snag, though.

"Start off by removing the coolant reservoir cap and the plastic bleeder screw right next to it. [...] rev the motor to about 2500 RPM [...] Watch the bleeder screw hole also, when coolant with no air bubbles begins to overflow then you're almost done."

I did all of the steps but I snipped these to state that nothing ever "began to overflow", instead there was a geyser shooting out of the plastic bleeder screw hole! I could never determine whether or not the mix shooting out of that hole had air bubbles in it or not!

So what I did was had my wife rev for awhile (about 2 minutes), all the while pouring 50/50 mix into the reservoir. I had a big'ole'mess to clean up. It did improve the heat at idle. It's not _HOT_ but it's definitely lukewarm where before it was downright cold (external temp). I don't know if I did it wrong, or didn't burp the system enough, but I stopped after such time as I had made enough of a mess.

[cooljess76]

Yeah, don't rev the engine with the bleeder screw removed. Just the radiator fill cap.

Personally, I don't even rev it at all, I just turn the heat on full blast and let the engine idle while I add coolant/distilled water with the bleeder screw out and the front of the car nosed up in my driveway.

I suppose it might help to rev the engine, but with the bleeder screw removed, you're just gonna make a mess and waste coolant.

[Severian]

Originally Posted by cooljess76

I suppose it might help to rev the engine, but with the bleeder screw removed, you're just gonna make a mess and waste coolant.

Yeah, that's what happened. So to sum up, I can remove the screw, let it idle, and add coolant as needed? Then when I notice that any coolant mixture coming out of the bleeder screw doesn't have bubbles I'm good to go?

This will be a much cleaner process.

[cooljess76]

Originally Posted by Severian

Yeah, that's what happened. So to sum up, I can remove the screw, let it idle, and add coolant as needed? Then when I notice that any coolant mixture coming out of the bleeder screw doesn't have bubbles I'm good to go?

This will be a much cleaner process.

Yeah, just make sure that the heater is on full blast and the front of the car is elevated making the bleeder hole the highest point in the cooling system(air bubbles travel up).

Doing it this way may take a few tries to get all of the air out of the system. It helps to massage the radiator hoses in hopes to wiggle every last air bubble out, but don't get your hands too close to the belts or the fan. Continue to add coolant until you see a steady stream of coolant/water flowing out of the bleeder hole with no air bubbles.

Hose the driveway down thoroughly as dogs like the taste of the poisonous antifreeze. Replace the bleed screw and radiator cap then drive the car around the block a couple of times. Let it cool down completely before removing the radiator cap and bleed screw and repeat the process a few more times as necessary.

[elchicano]

Yup just did it today turn on the heater and it was hot, I'll see if it really works now when i turn on my heater in the morning. I reved the engine with the bleed screw off, bad idea. A bunch of coolant burst out. But yea hope this fixes my heater issue.

[cooljess76]

Originally Posted by cooljess76

don't rev the engine with the bleeder screw removed.

Originally Posted by elchicano318ti

I reved the engine with the bleed screw off, bad idea.

c'mon Dave, don't make me tell you "I told you so"

[elchicano]

Originally Posted by cooljess76

c'mon Dave, don't make me tell you "I told you so"

My dumba$$ forgot, I have blead the radiator so many times. But while i was letting it idle i went inside to check on the temp gauge then some how i decided to press the gas and then theres goes the coolant everywhere. Oh well lesson learned.

[cooljess76]

I must confess, I learned the hard way too. Actually like you, I forgot and revved the engine a few times before I looked up to a geyser shooting out from under my hood. Even worse, I got blasted in the face at one of our meets in Angeles Crest. I was slowly cracking my radiator cap to relieve the pressure so I could add coolant. I knew it was still hot, but I thought I would hear the air hiss before the cap was completely loose. I guess I turned it 1 thread too much, but that sucker blew out of my hand and I got a gallon of boiling water in the face and chest! Luckily, I was wearing my sunglasses.

[elchicano]

Your lucky your were wearing your glasses, thats why i dont take those chances i rather wait for it to cool down. But yea i usually learn the hard way. But look at the positive side now you have a story to tell about you getting coolant in your face ha!

[bimmer95]

You have to start with the motor completely cold. If you start with a hot motor you WILL end up with a geyser on your hands. Revving a cold motor will merely ooze water out of the bleed screw.

[cooljess76]

That's just a bad idea. I've never heard or read in any manuals to rev the engine with the bleed screw off. The proper and printed way to do it is with the engine running, heater on full blast and with the car parked on an incline.

[elchicano]

Yea and eventually it will start to warm up and then its gonna gush out unless you wanna deal with radiator fluid everywhere then go on ahead and do it. But my problem is fixed i guess i was low in coolant or something.