New user with issues !

[E34Ireland]

Hi everyone - just joined up and hoping to find out some things.

I've got a 1995 E34 520i automatic. It originated in Singapore and is therefore classified as Japanese spec. I think. Largely it seems to be very similar to European spec. though.

First problem, the heating system. The A/C isn't woking and never has since I bought the car in Jan'05. I'm not too concerned about that at the moment though. What I am concerned about is the fact that any time I try to turn up the heater controls in the car, smoke starts wafting out through the vents. I am driving around at the moment with the heater controls turned to full cold - it's not until I try to turn on some heat that this problem arrises. Anyone got any idea what might be going on there ?

Also the rear window demister stopped working some time ago. I looked under the rear seat at the fuse box to find that an entire section of it had melted. Haven't figured that one out yet either but I'm about to get started on it.

Finally for now, I lock the car using the remote key fob. But when I lock it, the doors all lock and then unlock themselves again. So I've got to press the button once more which seems to tell the car the doors are now open again (which it already was anyway), and then press the button one last time to successfully lock it. Any ideas ? This one is really doing my head in !

[Karl]

Sounds like you may have some problems with wiring that has rubbed against the body some place to wear through the insulation, causing a short. Or perhaps previous owner did some wiring of his own to add an accessory and messed it up...

Start with the melted fuse box and make sure all the fuses are the right rating. If fuses are the right size, you can still get a hot spot in the fuse box from resistance due to dirty connection. Had that happen in my son's car. At least the fuse box will need to be replaced. Once that's squared away you can see what's under the dash at the heater controls.

For the door locks, check the archives--I know it's come up before, but can't remember the specifics, perhaps a bad ground.

[nyc525iTe34]

In regards to your heating/smoke issue....you might want to check the AC resistor pack to make sure it hasn't fried.

[Gayle]

Regarding the locks--what you are describing is a very common problem when the central locking system gets unsynchronized. It can be caused by manually locking or unlocking the doors. Here is a link to a thread that describes the resynch procedures.

http://www.bimmer.info/forum/showthread.php?t=7443&highlight=synchronize+locks

[Kalevera]

Interesting theories by the previous posters on the smokingly hot climate control situation. What does the smoke smell like? Does it fog up the windshield/front windows? I would put my money on a leaking heater core: coolant is leaking out, then vaporizing. If it were an electrical issue, it would be a one time only thing, and the car probably would have had a dash fire or wouldn't currently start. Heater cores are expensive, but they can be bypassed if the owner doesn't mind giving up heat. Could be a hard compromise for a cold Irish winter, aye mate.

Well, a previous electrical meltdown in the car might invalidate what I said above, but I'll still stick with it.

best, whit

[Bill R.]

heater core, especially if it has a sweet smell similar to maple syrup.




Interesting theories by the previous posters on the smokingly hot climate control situation. What does the smoke smell like? Does it fog up the windshield/front windows? I would put my money on a leaking heater core: coolant is leaking out, then vaporizing. If it were an electrical issue, it would be a one time only thing, and the car probably would have had a dash fire or wouldn't currently start. Heater cores are expensive, but they can be bypassed if the owner doesn't mind giving up heat. Could be a hard compromise for a cold Irish winter, aye mate.

Well, a previous electrical meltdown in the car might invalidate what I said above, but I'll still stick with it.

best, whit

[E34Ireland]

It's definately smoke and not any kind of vapour that pours out the vent. It doesn't cause the windows to fog up and smells like burning plastic - it's the only way I can describe it.

It has only happened twice. The first time I thought the whole car was going to go up in flames. But I quickly realised that turning the controls to full cold meant smoke wasn't pouring into the cabin.

So it was summer and didn't need the heater - I drove around happily with controls on cold and thought the problem had somehow rectified itself. Then one day I turned on some heat and smoke started billowing out again. It was at that point I made the connection between the heat controls and the smoke.

[Kalevera]

That's probably a wiring specific problem that can only be diagnosed by taking the thing apart. Such work could very well cost more than the car is worth if being performed by a mechanic. If you don't already own a copy of the Bentley manual, my suggestion is to buy one and start taking the dash out. Hacked electronics are bad news -- the body harness is large and complex, as well as expensive to repair and replace. The aircon box itself sits on a modular harness, but if it is shorting out enough to cause smoke, something is probably damaged back past that connector. Frankly, I'm surprised that the thing, let alone the car, still runs.

Earlier in the summer, I rebuilt a 325iC that had a trunk fire. Just to give you an idea of the kinds of issues that one might run into when doing this kind of work: resistances on the replacement wiring (I effectively replaced the harness from the rear seat back) were high enough to continually trip the check control brake light circuit test; that's not a problem that can easily be fixed/without taking the entire car apart.

If the car has a burnt rear ebox and evident electrical problems in the dash, it might be wise to consider how much time/effort/money you are willing to sink into what has evidently become "a project". You might be better off selling or parting this car and buying one with a clean history.

Sorry to offer such a bleak outlook on the issue. I am hardly an electrics expert, but I have performed a lot of electrical repairs and upgrades in my time, and can say with reasonable confidence that it will cost considerable money or time to make it 100% right.

best, whit