Does anyone have any ideas why my E46 does not blow heat when its stationary but I do get heat when the car is moving, the blower fans are working fine and the car is not overheating when stationary or when being driven
I would say you have air in the heater core, probably as a result of a slow coolant leak. A through inspection of cooling system, should reveal the problem, but it's most likely a crack down the expansion tank.
Do you mean you have no heat when the car is stationary and warming up, but you so when driving and warming up.. Or do you simply not have heat when stationary but you do when moving?
The first problem I have come to see as pretty common for e46s and just BMW's in general. If the second problem however, you should check and replace your cooling system. If you don't know when it was last replaced, replace it. A good rule of thumb for BMW cooling systems.
First thing you should do is check coolant levels daily and see if it is low/you have a leak somewhere. Also, open the OBC menu function 17 and monitor coolant temps to see if the thermostat is indeed on its way out.
Do you mean you have no heat when the car is stationary and warming up, but you so when driving and warming up.. Or do you simply not have heat when stationary but you do when moving?
The first problem I have come to see as pretty common for e46s and just BMW's in general. If the second problem however, you should check and replace your cooling system. If you don't know when it was last replaced, replace it. A good rule of thumb for BMW cooling systems.
First thing you should do is check coolant levels daily and see if it is low/you have a leak somewhere. Also, open the OBC menu function 17 and monitor coolant temps to see if the thermostat is indeed on its way out.
I came across this reply and you mentioned my exact problem in the first scenario but further addressed the second one. Mine only does it when warming up at idle but is fine once you begin moving.
What might be the cause of this in a 2004 BMW 325Ci Convertible 135,000 miles
Clarify please.. There is no heat coming out of ANY vents while standing still. Or are you referring to having the lower vents on, and no flow-through air coming out of the dash vents?
Not being a "Dick" just wanting information as I get no air from dash vents unless I am moving when the floor vents are the only ones on..
I don't know how an open thermostat would cause this problem. I can see it if the problem was the reverse: heat while idling, no heat while driving. For this situation an open thermostat doesn't fit.
Neotate, does your coolant temperature stay dead center when you are driving on the interstate? I mean DEAD center, not 2 degrees off.
The temp gauge is a bad indication of actual coolant temp. We know that the gauge is buffered from 75-105 (or is it 115, regardless) degrees celcius. The only true indication of coolant temp should be done using the OBC menu. Especially when diagnosing a potential problem with the car.
To Clarify I have air blowing when the car is stationary. the air flow is constant so i am getting air coming out of the vents, but its the air seems to get colder when I stand still, when I drive the air seems to get hotter. The temperature needle hangs around the centre of the guage as I'm driving down the motorway
with the car running started bleeding the system through the bleed screw first it was coolant then a lot of air came out and it was just air for 5 minutes still going, I've tightened up the bleed screw now. Am I supposed to bleed all the air out until coolant comes out from the bleed screw?
I had the same problem with a 330 at work, there is a valve that controls flow to the heater core located near the drivers side near the firewall, I forgettthe exact name of it but if I remember correctly theres 3 hoses that go to it, its kind of a pain to get but its there, if you follow the coolant hoses to the back of the drivers side of the engine bay you'll see it, that could very well be the problem
If that valve was stuck open or closed it wouldn't open/close while driving, it would always be stuck open or closed.
I think your water pump is failing, but that's just my .02 worth of experience with my cooling system. I would bleed properly and definitely keep an eye on the temp gauge and coolant level. The little hole just inside the ET fill neck should piss coolant when there is good flow. Maybe check that out while you're poking around.
Just bled the system and I'm still getting the same problem with only getting hotter air once the revs are higher, when idling the air starts to turn colder so it may sound like I have a problem with the heater core valve, does anyone know how much a heater core valve costs and how hard is it to replace?
I'm not entirely sure that the valve is the problem. One person has suggested your water pump. I guess it's possible, but I feel it is unlikely since your car is not overheating and the waterpump doesn't fade out in terms of flow rates. It breaks the bearing and makes the belt jump off eventually but doesn't lose flow capacity. The problem would be with the valve assuming a valve can get stuck in a position b/w open or closed. If it's stuck partially open then it's just not letting enough water through at idle, but when you increase the RPM, the flow increases and gives you hot water to the core.
You need to inspect these parts above before you buy the valve. It could just be a hose with a kink in it.
It's your water pump/thermostat. Listen to what everyone is telling you. The water pump is moving more water when your revs are high. Hence the warm air when moving. If it was the control valve you would not have hot air at all. But its your money. Piss it away as you see fit.
I just don't see how it's the water pump or the thermostat. The water pump doesn't just fade out. The impeller always works. The thermostat doesn't control flow to the heater core at all. The heat works if the thermostat is closed or open. In my opinion it has to be the valve or something in that part diagram I posted.
OP, can you tell us your cars water temperatures while at idle warmed up and while driving (at say 60-70 mph) warmed up? This will tell us if your thermostat is broken.
Have you inspected your system, OP, as in getting under the car, making totally sure there are no coolant leaks, removing undertray, running car, making certain nothing is leaking? When I had this problem, it turned out to be a crack in the expansion tank, as I said earlier, that was very hard to find. I saw evidence of dried coolant nearby and after removing the tank I found the crack. I would think bleeding the system, without identifying the problem is pointless.
If you want to test the heater valve, then just bypass it temporarily, see if that fixes your problem. I'm still sticking with leak though. Air in the system will find its way to the heater core.
Had a new water pump put in last year so unless I'm really unlucky I don't believe that has broken down, going to try to replace the heater control valve tomorrow and see how that goes, if anyone has any tips on replacing the heater control valve please let me know
Your last comment was two months ago. What's happened since then and is the problem solved? As you know, other people may have your same problem, so please let us all know the outcome.
Dont replace it just yet. Pop the hoses off and keep the electric connected. Have someone turn the heat on and off while looking through the valve to see if the plunger is moving up and down. It only moves a little so keep a close watch
How does a bad water pump sound? Im getting a high pitched whistle sometimes when I give it some throttle.. I know I replaced my water pump with a metal impeller (Graf) about 2 years ago.. Im also only getting heat when I rev to about 4k RPM its gonna be a cold winter.. no its not air. as a side note, due to a hole in between my head and block that shoots coolant out, i was forced to resort to a stop leak product. i was fine for about 2 years like this. looks like that crap has caught up and clogged all types of stuff up.
Sorry haven't posted, went on vacation then came back to reassess the problem. I removed both pipes going into the passenger side of the engine bayland flushed it all out with a hose.. a load of brown gunk came out, put it all back together and still no heat but it cleared out the system. Replaced the heater control valve and flushed the whole system. refilled it and bled it and now i get heat, i also had a minor leak somewhere so i dropped in some leak repairer which stopped the leaking so it was probably a combination of things which caused the issue. All fun and games now i got a whirling noise from the rear offside wheel so it looks like I got bearing to replace when it gets warmer.
Why on earth would you use a stop leak product unless you were planning on trashing the motor? In my situation I had a hole in the block.. I didnt have much choice. But to use stop leak when you can just fix it, is beyond retarded, sorry.. That crap clogged my heater core as well.
I also solved my intermittent heat problem by simply bleeding the cooling system.
So, before jumping to any conclusions and spending your hard earned $ on something you may not need right away, try that first.
My situation was that when this cold snap hit the northeast recently, I set the central dash vent to "red" and manually set the temp setting to around 75, figuring that should give me a little heat,
but nothing changed. And this was on the highway, so it should have started heating up pretty soon. I had to increase the temp up to the 91 limit before getting any heat at all. Then, when I set it back to around 75, all the heat stopped again.
So, the next morning, when everything was cooled down, I set the temp to the 91 limit, removed the ET cap and slowly opened the bleeding screw and heard air being pushed out past it while the coolant level float rose up to the top, so I didn't add any more coolant and just closed everything back up.
That's all I did and I had plenty of heat going into work that day. I did the same thing that evening before driving home and purged more air out of the system and now the system works like new again without spending a dime!
Hope this helps someone else with similar symptoms.
Hi all im new to this forum from the UK. Wondering if anyone can help me please as I have a similar problem....My 2000 e46 (191000 miles - manual) blows out cold heat when idle but warmer air when the car is moving.....I have also noticed that my coolant level drops somewhat (the amount of the narrow part of the ET where the cap fits) but has not gone so low that the car has overheated.This has been going on for abou 2-3 months now. Also my head gasket blew in july 13 but was repaired and so far so good its holding up well. In fact the temp gauge is bang on in the middle. I had thermostat replaced about 4 months ago. ET has been replaced twice (2007 and 2011). Radiator in 2009 and water pump also if i remember correctly. The other day in the parking bay at work i noticed some coolant under the car - not alot but enough to know there is a leak. I checked and could see the splashboard a little wet but could not spot a leak. The next day at work there was somemore coolant under the car - about the same amount. I checked the coolant level and it had dropped, the amount of the narrow part of the ET. There was still coolant in the ET. I drove home and as soon as got home i popped open the lid and could see some leaking under the ET, near that blue plug/screw that u can use to let out coolant. Im thinking that i will prob have a crack in the ET or a leak on/near that blue plug. Any help on this would be greatly appreciated! Thanks guys!
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