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the imitator 12-28-2012 03:33 PM

e34 535i Not getting any heat
Hello, thanks in advance for those who help.

I currently receive very little heat at idle, perhaps barely 60 degrees in the cabin while outside is 40 degrees or under.

Heres the info:
Heater valves seem to be working, I can twist the nobs from cold to full heat and hear and th valves pop open and close.

I do wake up in the morning to my windows being steamed up, but no smell of coolant, that or any sort of greasy condensation, its just water. This past summer while cleaning my car I did experience a slight water leak in my back window, but with that said I live in the Northwest and its currently the rainy season and the rear window shows no signs of leaking, but that obviously doesn't mean moisture can still get in, or out?

I did a micro filter change, which was quick and easy, but I did encounter lots of moisture in there as well, not physically on the filter but within the dash.

This all is pointing towards a bad heater core I feel..

The auxiliary pump could be corn, but I wont know til I get a meter to see if its doing anything. But being that most cars never used Aux pumps to begin with and have no problem heating up the cabin, this all has me thinking.

Thanks again.

Radian 12-28-2012 05:33 PM


Originally Posted by the imitator (Post 7276135)
But being that most cars never used Aux pumps to begin with and have no problem heating up the cabin, this all has me thinking.

The way that the circuit is plumbed into the system, without the aux pump, it won't get any appreciable flow to the cores. :thumbdwn:

Remove the cover that sits over the control valve/aux pump assembly, then with the vehicle running and warmed up, touch the individual hoses to see what's hot or not.

My car had chunks of head gasket jammed in the impeller. :eek:The nice thing is that the aux pump impeller housing is serviceable. You can take the entire thing apart and clean it out. Same with the control valves. Time consuming, but entirely worth it if they're plugged. :thumbup:

south26 12-28-2012 06:30 PM

If you need it I have a good pump for 25 plus shipping.


the imitator 12-28-2012 11:09 PM

Thanks for the responses guys.

Radian: You're absolutely right, the pump is to help assist flow, I was under the impression though that in this specific case that the auxiliary pump only showed noticeable difference when at idle in VERY cold weather, other then that it was deemed partially unnecessary since coolant flows fast/harder with RPM's.

and as stated but to be more specific, all 3 hoses at the firewall are hot at temp, with the hose leading back to the rear of the head (closest to firewall) being just slightly cooler than the rest, just barely noticeable.

If I sit at 4500 more or less rpm driving in gear the heat does NOT get significantly getting.
I have been using tap water with my coolant :tsk: shame on me.

Tomorrow i will go buy a few jugs of distilled water and perhaps attempt a basic heater core flush with a garden hose, and see if I cant successfully get any grime out of the core and replace as much of that city water as possible.

I "tested" a heater valve and pump i picked up from a wrecked vehicle in town, got it for very cheap and plugged in the leads to both the heater valve and the pump.
The valves are good but no spinning from the pump. The reason I put in quotations is because that may not be legitimate way to test this units pump.

BMWFatherFigure 12-28-2012 11:57 PM

Water in the heater box always a bad sign. Blown heater matrix or blocked drains. Check those out when you change the engine disolver (tap water) for real coolant. Reverse flush the heater, hoses off.

the imitator 12-29-2012 12:18 PM

Thanks BMWfatherfigure :P although I was indeed using a 50/50 mix the point still stands, its a no no. BUT, thats why I was pondering it being just water rather than that greasy steam you usually accumulate on your window associated with a leaking heater core.

My question now is, there are 3 hoses leading into the fire wall. 2 inlets and 1 outlet, do I need to plug one of these inlet holes before I try flushing? should I use a plunger? ... :p I usually let beavis and butthead work on my BMW. :thumbup:

Radian 12-29-2012 01:03 PM


Originally Posted by the imitator I need to plug one of these inlet holes before I try flushing?

Yep. Just one, then switch to the other. You can use your finger. No plunger required. :D

the imitator 12-29-2012 05:23 PM

Thanks radian.

With how new I am to this board (first board ive joined for BMW's) I hope people know I was just kidding about the whole plunger thing. lol

the imitator 12-29-2012 05:34 PM

Right arm! welp it looks like ill do my flush tomorrow. I have to do a valve cover gasket that had come loose overtime to my neglect and leaked towards the firewall, it leaked right where the rear main seal was, for about 3 minutes I was :thumbdwn: then felt the back corner of the valve cover pretty wet with oil and was all :thumbup: no problem.

so tomorrow will be a heater core flush since its quick, then a valve cover gasket.

Do any of you guys use or recommend putting a crease in the oil spray bar to deliver more oil to the outer cam lobes or is that just silliness?

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