Heater control valve

W

wiganz4

Member
Can anyone tell me where the heater control valve is on a 2005 2.0i (n46 engine) please?

Part number 64116917341 is listed as additional water pump on real o e m. This is easy enough to get to and replace as it's sat in a rubber housing with an electrical plug and 2 spring clip hoses but is it the heater control valve or water pump?

Cheers
 
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It's the auxiliary water pump.
The control valves are all located on the sides of the HVAC unit itself.
Talk to @bigwinn : he's just spent time messing about with those.
 
enuff_zed said:
It's the auxiliary water pump.
The control valves are all located on the sides of the HVAC unit itself.
Talk to @bigwinn : he's just spent time messing about with those.
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You mean the actuators, these are on the side of the HVAC unit, not control valves.
The part is listed as additional water pump rather than auxiliary. This is my confusion as it looks exactly like an E46 heater control valve and it's the feed into the heater core, which is what the control valve does.

So the question I really need answering is does this (part number 64116917341) control/regulate the amount of hot water going to the heater core or is there a separate component listed as the heater control valve? Hope that makes sense to someone.
 
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64116917341 isn’t an hvac control unit actuator

That’s the aux water pump
 
wiganz4 said:
So the question I really need answering is does this (part number 64116917341) control/regulate the amount of hot water going to the heater core or is there a separate component listed as the heater control valve? Hope that makes sense to someone.
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I thought my answer was clear, sorry.
It is an auxiliary coolant pump. It is simply a pump. It pumps coolant to the heater matrix. It does not have any valves in it.
It consists of a plastic housing holding an impeller. Coolant is supplied to one side of it and the impeller moves that coolant out of the other side and to the heater housing.
It provides full flow to the heater core, as it is simply driven by a 12v supply.
It does not regulate flow nor provide any controlling, valve-like function.
 
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enuff_zed said:
The actuators don't just sit there. They actuate valves on the HVAC unit
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Yeah I know. But a heater control valve controls water where as the actuators control air direction and hot/cold air mix. All my actuators are fine. I need to know why, or if there's supposed constant hot water flowing into the matrix via the additional pump. I've constant hot air coming from the demist vents, increasing as I speed up! All flaps, fan dials, directions, recycle are working. A/C blows ice cold. Foxwell scanner tells me additional motor is running 100% and that's my worry. Should it run at 100% constantly, even if the heater is set to cold. This is why I asked if it was a motor or control valve. Might sound a daft question to some but I'm working by elemination and I'm running out of ideas. 🫣
 
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wiganz4 said:
Yeah I know. But a heater control valve controls water where as the actuators control air direction and hot/cold air mix. All my actuators are fine. I need to know why, or if there's supposed constant hot water flowing into the matrix via the additional pump. I've constant hot air coming from the demist vents, increasing as I speed up! All flaps, fan dials, directions, recycle are working. A/C blows ice cold. Foxwell scanner tells me additional motor is running 100% and that's my worry. Should it run at 100% constantly, even if the heater is set to cold. This is why I asked if it was a motor or control valve. Might sound a daft question to some but I'm working by elemination and I'm running out of ideas. 🫣
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Well I had one fail so I wired it directly to an ignition live so it ran constantly. I never had any untoward symptoms like you describe?
Are you certain all the actuators are operating correctly? There is one on the right side of the heater assembly called the servo drive for the defroster flap? Maybe this isn't closing the flap? Perhaps the actuator is working but the physical connection to the flap has failed?
As far as I can tell there is nothing to stop hot coolant flowing through the matrix all the time. It is simply down to flap positions whether air is passed over the matrix to heat it, or to direct that heated air to the various vents.
 
enuff_zed said:
Well I had one fail so I wired it directly to an ignition live so it ran constantly. I never had any untoward symptoms like you describe?
Are you certain all the actuators are operating correctly? There is one on the right side of the heater assembly called the servo drive for the defroster flap? Maybe this isn't closing the flap? Perhaps the actuator is working but the physical connection to the flap has failed?
As far as I can tell there is nothing to stop hot coolant flowing through the matrix all the time. It is simply down to flap positions whether air is passed over the matrix to heat it, or to direct that heated air to the various vents.
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Well today I've had to drive from Telford to Lancashire and I've done it with a towel covering the intake grille on the scuttle panel as an experiment. As the air flow, and noise, increase with speed it has to be connected. Plus everything's working, including temperature shift and direction using the controls. It looks like the fresh air intake actuator is either stuck open, being told to stay open or loose and the air flow is passing straight thru it, hence the issue I've got as by default air is guided to the screen vents. I'm home now and just disconnected battery with lights left on to rinse any power out. I'll reconnect in the morning to see if that resets the system. I know I can see the air inlet actuator when I do the pollen filter as it's on the far left hand side of the unit so I'll remove the glove box and see what I find.
 
Bit blurry but I should be able to at least see the actuator I think if the issue.
 

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wiganz4 said:
Well today I've had to drive from Telford to Lancashire and I've done it with a towel covering the intake grille on the scuttle panel as an experiment. As the air flow, and noise, increase with speed it has to be connected. Plus everything's working, including temperature shift and direction using the controls. It looks like the fresh air intake actuator is either stuck open, being told to stay open or loose and the air flow is passing straight thru it, hence the issue I've got as by default air is guided to the screen vents. I'm home now and just disconnected battery with lights left on to rinse any power out. I'll reconnect in the morning to see if that resets the system. I know I can see the air inlet actuator when I do the pollen filter as it's on the far left hand side of the unit so I'll remove the glove box and see what I find.
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I think we are on similar lines? There is nothing to stop air coming into the car, but if that flap is not closing it will pass over the matrix, get hot and come out the top.
What @bigwinn suggests will tell you if the actuators are working, but of course does not prove if they are still connected to the flap they are supposed to be moving.
 
bigwinn said:
The actuators can all be moved using inpa

Do you have it?
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No. I only have a Foxwell nt510 but this tells me all the actuators are working, and which ones as well as to what percentage. But as we know this is just the motor. My thinking is a more physical issue and the flap or link is loose or broken. This is why I'm trying a reset, and I'll have a look best I can tomorrow.
 
You're not gonna believe this. And I'm almost embarrassed to tell you but not really.

Turns out my problem is........

Car needs 2 new front wheel bearings!

Drivers side worse than passei but that's the problem.
So why the issues I have been having?
The heater box is acting as an amplifier as it's bolted to the chassis, for both noise and the very slight vibration which in turn is moving not just noise but heat to the only open vent as the increasing noise and vibration occur with increased speed and also more load when turning the steering. The only escape is always the screen vents as they are designed to omit air by default, even when heating is off.

Crazy but true. And the mechanic who I use told me I'm not the first and won't be the last with a Z4 and now Mini convertible to turn up with this conundrum. Especially as there's no noise or vibration from any of the front wheels while driving and listening from the outside. Difference is I've diagnosed mine to my limit (and sanity) before losing the battle where as most turn up thinking their heater system needs replacing.

Cheers to you both for the help/replies.
Every day's a school day eh!
These cars definitely become a love/hate relationship.
 
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