Coolant and no heat!

**craigd4937** · 02-15-2018, 11:42 AM

Hello guys first post here! I have an issue! I have no heat in the cab! I checked the water valve and its working and the heater core is clear.
So I checked the line running to the engine from the water valve and there nothing coming out with the engine running! I was thinking maybe it needed to warm up, the engine,
didn't matter, So I need help! I don't want to have to remove the intake manifold.....

Craig

**Ken Rada** · 02-15-2018, 11:51 AM

Originally Posted by craigd4937

Hello guys first post here! I have an issue! I have no heat in the cab! I checked the water valve and its working and the heater core is clear.
So I checked the line running to the engine from the water valve and there nothing coming out with the engine running! I was thinking maybe it needed to warm up, the engine,
didn't matter, So I need help! I don't want to have to remove the intake manifold.....

Craig

Could be low on coolant. Maybe there is a slow leak coming out of one or both of the rigid pipes under the intake manifold. That is where my leaks were coming from. If that is the case you will need to remove the intake manifold and replace those pipes.

Sent from my LGLS992 using Tapatalk

**craigd4937** · 02-15-2018, 12:00 PM

Might be, I have bled that thing probably twenty times... I tried to flush that with a garden hose and it seemed like it had a blockage, nothing went in....
I thought I would have to take that off dammit... I was hoping for some kind of trick....

Craig

**dworthy** · 02-15-2018, 01:05 PM

So how did you test the heater valve? If you unplug it, it will always default open, then you can check to see if the hoses going into the heater core is getting hot, as well as the return line is also warm.

How did you bleed the system? Just filling it up with 50/50 coolant and distilled water mix just won't do the trick. Even using the bleeding valve, is useless unless you have the front end elevated.

**craigd4937** · 02-15-2018, 02:18 PM

I removed it and put 12v to it and watched it close. the heater core is fine i ran water thru it and its all good. I jacked up the front of the car and removed the bleed screw, poured coolant in until the bleed opening had no bubbles, put the ignition on and turned on the heater for five minutes added more coolant and then drained abit and it was good to go about 20 times...but here's the deal, I take the line off of the water valve that goes to the engine and NOTHING comes out....

**dworthy** · 02-15-2018, 02:25 PM

Indeed interesting.

Are the hoses even getting hot at the heater valve? When you do an "Old Skool" bleed, it will take 10-15 minutes before the thermostat open and you start to get heat then.

**craigd4937** · 02-15-2018, 10:46 PM

Ok, i let it heat until the needle on the temp gauge was in the middle and still no heat or coolant coming out of the line...so?? Is that long enough??frickin car!!

**dworthy** · 02-16-2018, 12:59 AM

Is this with the interior temp set to max? Also to confirm it is the heater valve, unplug it and see if that fixes it. Leave the hoses alone, everytime you open a hose, you have to re-bleed the system.

**craigd4937** · 02-16-2018, 08:27 AM

Yes, with the heat set on 91. and yes i have unplugged the car, I have driven this car for hours, it doesn't overheat and the gauge goes from cold to the middle and stays there. Now I dont want to do mork
work thats not needed, but its looking like I'll have to remove the intake manifold and see whats going on with the tubing that runs from the valve to the motot...

Craig

**MarcoZandrini** · 02-17-2018, 07:23 AM

It’s not a problem at the top of the engine. Did you check the temperature of the hoses at the heater control valve? I’m betting that the heater core is blocked. Remove the 2 hoses that go through the firewall. Take a garden hose to one (it doesn’t matter which one) and try to run water through the core.

**craigd4937** · 02-18-2018, 10:46 PM

The heater core is NOT blocked.as i mentioned before, i put the hose to them and they were running both ways.. as i mentioned before, the hose that runs out of the engine and runs to the valve has nothing comeing out of it even running for more than an hour...so any help wound be appreated...
PS read my posts before answering...

Craig

**dworthy** · 02-19-2018, 03:43 AM

So the cliff notes:

1. Heater core isn't blocked and confirmed by running water thru both directions.
2. With the heater valve unplugged you get zero heat.
3. With the heater valve plugged in and the controls set to max still no heat.
4. Coolant system is fully bleed and no air bubbles present.

If all above is true, then I would replace the heater control valve as it seems to be jammed shut.

**craigd4937** · 02-19-2018, 08:19 AM

Do you mean the water valve?? I have checked that and with the power off its straight thru, as I said before, when I apply power the valve shuts so if this is the valve its working as it should....

So lets go over this heater coolant system...when the car warms up, it opens the thermostat, which in turns lets coolant go into the motor and up to the line that goes to the water valve which in turn goes into the heater core and thru to the expansion tank...and repeats..correct?

**craigd4937** · 02-19-2018, 08:27 AM

Could there be something clogged in the tube from the valve to the motor? I have tried to backflush it with the hose, and it wont clear, if its blocked....

Craig

**dworthy** · 02-19-2018, 10:50 AM

Well you get the hot water from the motor, and the thermostat doesn't need to be open for the water to flow thru the valve. It is rounted under the motor just behind the waterpump on the head and thru a plastic tubing. Around cylinder 5, there is a connection to a rubber line which goes to the heater valve. From the heater valve, it goes to the firewall connection, should be the closest to the driver IIRC. The outflow will go to your expansion tank, and dump the cooler water there.

So what maybe happening is that plastic coolant pipe under the intake is blocked. Is the water or the heater valve itself hot after driving for 20-30 minutes?

**craigd4937** · 02-19-2018, 12:36 PM

No, maybe luke warm.....so is it possible to get to some of that under the engine? and I guess I didn't explain what happened. I was driving to work and had noticed the temp gauge was climbing and almost to the red the temp, thats when the heater stopped working, when I got off the freeway, I was in the red and had stopped and was letting it cool down. when I got it to work it was steaming and figured it was the thermostat, changed it out and now the car doesn't overheat, but no heat out of the vents, just cold air.....

**dworthy** · 02-19-2018, 02:06 PM

Since you replaced the thermostat, has the car overheated? Remember that the water pump is made out of plastic, and the impeller can break-off causing the car to overheat.

Also since that temp gauge is very buffered in the middle, from 120F to 210F, so lets see what the temps to get to:
http://www.bmw-driver.net/forum/showthread.php?t=31204
Function #7 is the actual temp for the motor, so take it for a drive and let me know what the temp actually is.

**craigd4937** · 02-19-2018, 03:08 PM

No it hasnt overheated.. The needle stays in the middle....and ill see when Ill drive it later in the week. and Ill let you know...
Thanks for all your help...

Craig

**MarcoZandrini** · 02-20-2018, 07:42 AM

Google “BMW E46 hidden OBC functions.” Test #7 shows the engine temperature as seen by the engine computer (DME).

**dworthy** · 02-20-2018, 12:04 PM

No problem, just to function 7 and let us know.

**bmwbob89** · 02-22-2018, 08:22 AM

You can see if the water pump is circulating by running the engine with the rad cap off. You will see the coolant moving if you have someone rev it up a little. Next try and backflush the coolant hose that goes to the heater valve.

**craigd4937** · 03-02-2018, 08:46 AM

Ok, I removed the intake and found the coolant line that ran from the engine to the heater (water) valve was clogged with this stuff that looked like a yellowish plumbers putty... And the end of the plastic line that went into the motor was leaking so i replaced both of the plastic lines and while I was at it the CCV system also. So this weekend is going to be putting it back together. Do you happen to know the torque specs on the intake? So I'll keep you posted...;.

**dworthy** · 03-02-2018, 09:32 AM

M7 = 15NM
M8 = 22NM

Make sure you get new intake seals, as the original ones will be hardened.

**Eaglesail** · 03-02-2018, 02:06 PM

Dworthy...In addition to this posting...I also have issues concerning the overall of my heating system in my 325. I will not plague you to this post for my different....expect you may hear more and especially from me again ...at another time ..on here.

**craigd4937** · 03-02-2018, 02:33 PM

[QUOTE=dworthy;29966326]M7 = 15NM
M8 = 22NM

Make sure you get new intake seals, as the original ones will be hardened.[/QUOTE

Yes, I have new seals for the intake....I'm excited to get this back on the road!