HEATER PROBLEM

[jpvd]

Hi All

New on here, but wanting to ask for some help...

I have a z4 2.2 on a 2003 plate.

having a problem with the heaters, where the passenger side is blowing cold and the drivers side hot. I've flushed the whole system, back flushed the heater core. There was a fair amount of sludge build-up (brown gunk) that must have been caused by old coolant or lack of coolant and previous owner using water. Flushed and back flushed 3 times, new coolant added and followed bleeding procedure (bottle on coolant cap, etc) until no air bubbles.

Still have the problem.... :headbang:

now the car does'nt have dual zone climate control or anything like that, but I'm wondering if it is a mechanical problem - stuck flap, steeping motor, etc..... Almost bought a new heater core, but don't fancy fitting this as it will probably be a nightmare....

Has anyone else come across this problem and if so how did you solve it....driving me nuts as the wife moans about being cold all the time when we go out for a spin, so needs sorting.

thanks in advance....

Paul

 

[jpvd]

Nobody have any ideas?...can't be the only one

 

[centuryboats]

My money would be on the flap doors

 

[raymond.harper]

https://www.google.co.uk/url?sa=t&source=web&rct=j&url=http://www.bmwclub.lv/files/07_E85_Heating__and__Air_Cond.pdf&ved=0ahUKEwjzpvKW--LRAhUHAcAKHeNGDBg4ChAWCCYwAw&usg=AFQjCNFqlkECcice3b3wvS8acvUz9Jk3Xg&sig2=nTLwQvx3_vcaiLi_dGSb1A
An overview of the system.

 

[jpvd]

Nice one..thanks for the info, will see whatican find

 

[gioxtom]

Hi, i have same problem. Have you find solutions?

 

[Marius]

Do simple test. Keep revs high at 4-5k rpm for few minutes and if you get warm/hot air on all vents it's a headgasket.

 

[Ewazix]

Do simple test. Keep revs high at 4-5k rpm for few minutes and if you get warm/hot air on all vents it's a headgasket.

Now that's how to the $hits up someone! :lol:

 

[alekos911]

If it was a si, I would say that the water pump might be the culprit.

 

[Ewazix]

Hi All

New on here, but wanting to ask for some help...

I have a z4 2.2 on a 2003 plate.

having a problem with the heaters, where the passenger side is blowing cold and the drivers side hot. I've flushed the whole system, back flushed the heater core. There was a fair amount of sludge build-up (brown gunk) that must have been caused by old coolant or lack of coolant and previous owner using water. Flushed and back flushed 3 times, new coolant added and followed bleeding procedure (bottle on coolant cap, etc) until no air bubbles.

Still have the problem.... :headbang:


Paul

The lack of pin-point suggestions is probably down to there being so many possible causes, you've done the right thing by starting with the basics of the cooling system, I'd only add that the M54 engine is famously difficult to bleed and the heater core is the furthest point so will catch air. I've seen how-to's suggesting the front of the car needs to be raised a bit on a slope or ramps and I would really eliminate bleeding before going deep. Obviously you suspect your heater core because of the gunk in the system and it may come to that, but I'd find some tech info on getting to the flaps, actuators and any flow valves beforehand as a couple of members have had those going down.

If it's not overheating, losing coolant, running rough or getting oil/water - water/oil exchange then it's unlikely to be head gasket. A lazy thermostat however is possible preventing proper hot running. You might get engine fault codes with a 'stat problem so is worth checking, try the mobile Torque-pro app if you haven't got a fault reader as this will confirm engine running temps as well. Let us know how it goes

 

[Marius]

Do simple test. Keep revs high at 4-5k rpm for few minutes and if you get warm/hot air on all vents it's a headgasket.

Now that's how to the $hits up someone! :lol:

Well known m54 problem.

 

[jpvd]

Do simple test. Keep revs high at 4-5k rpm for few minutes and if you get warm/hot air on all vents it's a headgasket.

Now that's how to the $hits up someone! :lol:

Well known m54 problem.

doubt its the head gasket....just changed the oil and filter, oil looked fine, just dirty - not milky....no steam form exhaust and runs spot on...

I'm still thinking its an airlock in the heater core....I've tried the bottle trick and parked it on a hill and bled it....I'm considering dropping the coolant again, flushing it again with some stronger coolant flush and then refilling and seeing if that fixes it.

I've had a look under the dash, but its a bloody nightmare to get to anything and i can hear all the motors working when i turn the knobs and alter temp, etc.....

the coolant was really bad - brown with lots of gunk and sediment - probably down to the last owner not doing a proper flush....its clean now and i ran a hose pipe through the whole system until it cleared - attached it to the flow and return pipes in the bulkhead to flush the heater core too.....also the flow into the core is hot and the return is just as hot too, so would expect the temp to drop??....

mystery...will try bleeding again and see where i get....as for the water pump and stat, these both seem fine too - flow is good and stat is opening and closing - plus on the motorway the engine temp doesn't drop....

one question though - could this problem be caused if the a/c is low on gas?......as the air con isn't cold, so needs a re-gas...could ti be connected?

thanks again

 

[Ewazix]

May be of interest, http://www.z4-forum.com/forum/viewtopic.php?t=43687


If you are running the aircon when you are testing and getting different hot - cold on the pass' and driver's sides as described, then yes low gas could do this, but if you are not running the aircon then I can't see it.

 

[Mike6]

One trick I have used on other cars is with engine running at operating temperature and then grap hold of one of the large rubber hoses coming out of the radiator and giving it a good squeeze a number of times. You may hear a gurgling sound and the level in the header tank go up and down. You could then perhaps try the other pipe - flow in and flow out hoses. This will often cure an air lock in the system but havent had to do this on my Zed so not sure how accessible the hoses are.

 

[jpvd]

well its been a while since i last posted on this!...still not sorted the issue, since other things took priority and it just got left...

back on it now and trying to get it fixed as I am driving the car all year so need the heaters when the temp drops...further to what i said above, the two pipes that run into the bulkhead (flow and return) both are hot once the engine has warmed up, so there is a flow of hot water through....therefore i doubt the matrix is blocked.....i am still leaning towards a failed motor or vent....

does anyone know for sure if the matrix is dual core and if so does it have a bypass for if one side gets blocked??

such a pain and shame the fault code reader can't find the problem....would make it far easier!... :rofl:

 

[longshaw]

well its been a while since i last posted on this!...still not sorted the issue, since other things took priority and it just got left...

back on it now and trying to get it fixed as I am driving the car all year so need the heaters when the temp drops...further to what i said above, the two pipes that run into the bulkhead (flow and return) both are hot once the engine has warmed up, so there is a flow of hot water through....therefore i doubt the matrix is blocked.....i am still leaning towards a failed motor or vent....

does anyone know for sure if the matrix is dual core and if so does it have a bypass for if one side gets blocked??

such a pain and shame the fault code reader can't find the problem....would make it far easier!... :rofl:

Hey,
I have same issue ... or rather the Mrs has this issue :wink: Passenger footwell heater "not working"
Have you managed to resolve yet? and what would you try in what order to resolve this?

 

[jpvd]

well its been a while since i last posted on this!...still not sorted the issue, since other things took priority and it just got left...

back on it now and trying to get it fixed as I am driving the car all year so need the heaters when the temp drops...further to what i said above, the two pipes that run into the bulkhead (flow and return) both are hot once the engine has warmed up, so there is a flow of hot water through....therefore i doubt the matrix is blocked.....i am still leaning towards a failed motor or vent....

does anyone know for sure if the matrix is dual core and if so does it have a bypass for if one side gets blocked??

such a pain and shame the fault code reader can't find the problem....would make it far easier!... :rofl:

Hey,
I have same issue ... or rather the Mrs has this issue :wink: Passenger footwell heater "not working"
Have you managed to resolve yet? and what would you try in what order to resolve this?

hi - still trying to resolve it.....looking at soaking the heater core with limescale remover overnight and then flushing again..see if that works....its not an airlock, all the motors and flaps seem to be working ok, both pipes are hot going into the core and i've checked the thermostat is opening and closing, which it is....so it all points back at the heater core....so will let you know how i get on, as should be doing it next week (was supposed to do it today, but my starter motor dies so that's this weekend job now!)

thanks

 

[longshaw]

Thanks, how did you know how to check all the things you’ve mentioned? are these easily checked? keep us in the loop.

 

[JGB2018]

Hey guys, very interested in this post. jpvd did you manage to resolve the issue at all?

J

 

[jpvd]

well i had a try at pumping through some heavy duty limescale remover, using some length of rubber hose, a drill attachment water pump and two buckets. Left it pumping through for an hour or so and left it to soak for the same. I did get some milky white sediment come through so it definitely cleaned something, but I do wonder if it is worth leaving it overnight to really soak in.

anyway connected it back up, bled the system and it is still cold on passenger side. did go for a drive and after a while the passenger side did warm slightly, but not by much. So it is either the heater core which is still blocked up or it could be a flap, although i cannot see how a flap would cause this issue since the z4 doesn't have dual climate control so no need for separate flaps??

may try soaking the heater core once more and also having a look behind the dash again for any slipped cables or connectors.....

also on another note both the flow and return pipes to the heater core are hot so nothing to do with stat or pump - also i plugged the scanner in and watched the live data which shows coolant temp and radiator temp, so you can tell when the stat opens and the radiator fills and that seemed all good....

driving me nuts...winter time and the car interior is just not warming up.....dammit!! :thumbsdown: :fuelfire: