89 e34, electrical buzz B4 start, ALSO, starter churns, engine wont fire.

[CharlesAFerg]

Hey guys, I have a bmw e34 525i from 1989 that has a few small electrical problems I am dealing with. I just recently replaced that inner dash unit with the capacitors and all to deal with some problems, I thought this was included but apperently its related to soemthing different because all the other dash problems like my odometer not working are now fixed. Anyways, here is the problem I am facing now..

When you turn on the ignition and all of the electrical BEFORE the car STARTS, I get this buzz and vibration coming from inside the dash near the AC and radio, basically high center. I know there is always a buzz AFTER the car is SHUT OFF on most e34s in the same area, but this buzz is louder, it rattles, and it doesnt stop after 20 seconds or however long the other one lasts. This continues until you turn the electrical off.

Also, my air conditioning fan seems to cut on and off randomly in long intervals if I turn it on, so I don't know if this is connected or not, but it's all in the same area so it could quite well be.

Also, if you guys know how much new water pumps cost that would also help me a lot, because apperently mine is not circulating enough and I'm running hot.

Thanks guys, I hope my description helps you diagnose the problem...

[CharlesAFerg]

Also, my *brake light* warning comes on.
(I heard about an "LKM" problem and there is something in the fuse box, please explain if this is the problem)

AND

I get a warning saying +38 degrees, or +18 degrees (whatever the temperature it says) I don't know what it's talking about, maybe my bad water pump. I don't know.
Thanks!

[dacoyote]

Also, my *brake light* warning comes on.
(I heard about an "LKM" problem and there is something in the fuse box, please explain if this is the problem)

AND

I get a warning saying +38 degrees, or +18 degrees (whatever the temperature it says) I don't know what it's talking about, maybe my bad water pump. I don't know.
Thanks!

First thing to check on the brake light warning is..... Make sure they work, check the bulbs and stuff

The 38 degree warning is a freeze warning, not a big deal to worry about. As in it's something it suppost to do.

-Charles

[Javier]

When you turn on the ignition and all of the electrical BEFORE the car STARTS, I get this buzz and vibration coming from inside the dash near the AC and radio, basically high center. I know there is always a buzz AFTER the car is SHUT OFF on most e34s in the same area, but this buzz is louder, it rattles, and it doesnt stop after 20 seconds or however long the other one lasts. This continues until you turn the electrical off.

Also, my air conditioning fan seems to cut on and off randomly in long intervals if I turn it on, so I don't know if this is connected or not, but it's all in the same area so it could quite well be.

Quite convinced you have a blower issue with the A/C. Try removing the fuse F19 (Blower fuse). If the ratling stops, yes it is the blower.

how much new water pumps cost that would also help me a lot, because apperently mine is not circulating enough and I'm running hot.

I paid about 50 USD for a 535i one last time, but you may need a new tstat or fan clutch instead of a new pump. Check Bruno's site on Overheating.

http://www.bmwe34.net/e34main/trouble/overheating.htm

my *brake light* warning comes on. (I heard about an "LKM" problem and there is something in the fuse box, please explain if this is the problem)

Understand Break light is different than break light circuit. If lights are OK, check your lamps sockets, use original lamps replacement only, and yes, check the LKM, also per Bruno's site.

http://www.bmwe34.net/e34main/maintenance/electrical/LKM.htm


I get a warning saying +38 degrees, or +18 degrees (whatever the temperature it says)

If it is what I guess (OBC warning), it's -38 (or about, not sure on the exact value) degrees, it is typical from a disconnected thermo probe in the front bumper, telling the OBC that temperature is extremely low.

The OBC displays an alarm when outside temperature is below -3 degrees (or about, not sure on the exact value) in order to warn you that there may be ice surfaces on the road.

Good luck
Javier

[uscharalph]

Check www.bmaparts.com for their price. My 1989 E34 525i (M20) was also having cooling problems. It still had the original radiator and water pump. We just replaced those plus the thermostat and all the hoses for under $450.00 in parts. The needle stays at 12 o'clock now. I got all the parts from BMA except the radiator which I got off eBay. If I had it to do again, I might spend a little more on the water pump and get it from the dealer, depending on the part brand they use.

[Kalevera]

I have to say that I think the "rattling" is simply the ventilation flaps opening. It's supposed to do this....good first post, missed the "read this before posting" message up top, eh?! :D

Nah, I'm just rattling your feathers :) Read the FAQ on Bruno's site...bmwe34.net. Somehow I have this feeling that the car is a new acquisition and a lot of items can be easily answered with a thorough surfing of that site or by doing a search on the forums.


best, whit

[CharlesAFerg]

When you turn on the ignition and all of the electrical BEFORE the car STARTS, I get this buzz and vibration coming from inside the dash near the AC and radio, basically high center. I know there is always a buzz AFTER the car is SHUT OFF on most e34s in the same area, but this buzz is louder, it rattles, and it doesnt stop after 20 seconds or however long the other one lasts. This continues until you turn the electrical off.

Also, my air conditioning fan seems to cut on and off randomly in long intervals if I turn it on, so I don't know if this is connected or not, but it's all in the same area so it could quite well be.

Quite convinced you have a blower issue with the A/C. Try removing the fuse F19 (Blower fuse). If the ratling stops, yes it is the blower.

how much new water pumps cost that would also help me a lot, because apperently mine is not circulating enough and I'm running hot.

I paid about 50 USD for a 535i one last time, but you may need a new tstat or fan clutch instead of a new pump. Check Bruno's site on Overheating.

http://www.bmwe34.net/e34main/trouble/overheating.htm

my *brake light* warning comes on. (I heard about an "LKM" problem and there is something in the fuse box, please explain if this is the problem)

Understand Break light is different than break light circuit. If lights are OK, check your lamps sockets, use original lamps replacement only, and yes, check the LKM, also per Bruno's site.

http://www.bmwe34.net/e34main/maintenance/electrical/LKM.htm


I get a warning saying +38 degrees, or +18 degrees (whatever the temperature it says)

If it is what I guess (OBC warning), it's -38 (or about, not sure on the exact value) degrees, it is typical from a disconnected thermo probe in the front bumper, telling the OBC that temperature is extremely low.

The OBC displays an alarm when outside temperature is below -3 degrees (or about, not sure on the exact value) in order to warn you that there may be ice surfaces on the road.

Good luck
Javier


Sweet, thanks for the info, anyways first I know that I just got a new thermostat for my car, but I will definately look into a new fan clutch as well, that really could be the problem. I took it to a place my family goes to, really great w german autos and they said it might be getting poor circulation, he did a temp reading and he said it was like 230 something on one side and 210 on the other, whatever that means.

Second, I checked the lights and their ok, but I'm worried that they work sometimes but when the warning comes on their not lighting, I can't tell. But I had someone check it when I got home and they worked, so I'm hoping its only the warning. I'm not quite sure what you mean about the light circuits and lamp sockets and stuff wtc.

Third, the temp couldnt possibly be a freze warning, it's 95 outside here right now, as it was when I was driving yesterday, so It must be some error, it was scorching hot, probably worse inside my car because I had the heater going to help cool the engine...yeah, extremely ..."ghetto".

Thanks Javier, lots of great info in your response, I appreciate it
-Charles

[CharlesAFerg]

I have to say that I think the "rattling" is simply the ventilation flaps opening. It's supposed to do this....good first post, missed the "read this before posting" message up top, eh?! :D

Nah, I'm just rattling your feathers :) Read the FAQ on Bruno's site...bmwe34.net. Somehow I have this feeling that the car is a new acquisition and a lot of items can be easily answered with a thorough surfing of that site or by doing a search on the forums.


best, whit

Actually I looked on the FAQ and saw the part about them closing, but it didnt do it 5 min ago when I tried it so it must be some ittermitent thing, it was loud compared to the valves closing. Anyways, I appreciate the concern :-D, I don't like forum noobs either. It is a new aquisition, but like I said earlier, I jsut got a new dash instrument component, so I was quite frustrated when I was confronted with further electrical problems of a similar nature.
ciao!
-Charles

PS- I wish my sig would show up :-/

[Kalevera]

Actually I looked on the FAQ and saw the part about them closing, but it didnt do it 5 min ago when I tried it so it must be some ittermitent thing, it was loud compared to the valves closing. Anyways, I appreciate the concern :-D, I don't like forum noobs either. It is a new aquisition, but like I said earlier, I jsut got a new dash instrument component, so I was quite frustrated when I was confronted with further electrical problems of a similar nature.
ciao!
-Charles

PS- I wish my sig would show up :-/
Hi Charles.

Please excuse my jerkoff-ish ways in the earlier message. Having new people on the forum is what makes it fun, so, indeed...welcome! I really was just messing around before. d00d posted that sticky a long time ago and everyone seems to ignore it, which I find rather amusing :)

Anyway, back to your car. Mr. Thoughtful (me) read the initial post again. On the aircon fan -- does this refer to the cabin blower or the aux fan, mounted in front of the radiator? If it's the inside fan, the resistor sword (on your car) is known for causing problems. I'd be looking at the IHKA control module and interface module if the blower is intermittant, versus only working on full blast. If it's the aux fan, pull the temp switch on the top passenger side of the radiator and jumper brown (ground) to each of the other two pins with the ignition turned to run. The fan should come on low and high speed, respectively. If the operation is intermittant, check the low speed relay and the ballast resistor.

On water pumps: hepu or graf. Winfred hates Geba. I own one but can't comment. It's a $50 deal from the forum favorite, bmaparts.com. Call Patrick and mention ".info" and you'll get an even better discount over what they'll offer you on the phone (which is lower than whatever the web site says, anyway).


best, whit

[Javier]

"Brake light circuit" that is fixed (most of the times) by replacing the brake light switch around the brakes pedal.

I'm not quite sure what you mean about the light circuits and lamp sockets and stuff wtc.

The goodness of a lamp is tested by the LKM trough the monitoring of the lamp current. If there is an extra resistance in the circuit or a high resistance short circuit the current will run lower or higher that expected, generating an alarm signal. Other than LKM problems, alarms on lamps can be caused by non original bulbs having a current consumption different than originals, dirty lamp sockets having high contact resistance to the lamps contacts, dirty or wore connectors along the harnesses, and of course, the star of all bugs "THE TRUNK HINGE PHENOMENA" genetically embedded in our E34's.

Javier

[JonE]

Hey guys, I have a bmw e34 525i from 1989 that has a few small electrical problems I am dealing with. I just recently replaced that inner dash unit with the capacitors and all to deal with some problems, I thought this was included but apperently its related to soemthing different because all the other dash problems like my odometer not working are now fixed. Anyways, here is the problem I am facing now..

When you turn on the ignition and all of the electrical BEFORE the car STARTS, I get this buzz and vibration coming from inside the dash near the AC and radio, basically high center. I know there is always a buzz AFTER the car is SHUT OFF on most e34s in the same area, but this buzz is louder, it rattles, and it doesnt stop after 20 seconds or however long the other one lasts. This continues until you turn the electrical off.

Also, my air conditioning fan seems to cut on and off randomly in long intervals if I turn it on, so I don't know if this is connected or not, but it's all in the same area so it could quite well be.

Also, if you guys know how much new water pumps cost that would also help me a lot, because apperently mine is not circulating enough and I'm running hot.

Thanks guys, I hope my description helps you diagnose the problem...

Ok! So, here is my take on a few of your items.
1. If heater/AC cabin blower intermittant and always "on" when on #4 or "high" speed, it is probably the "sword" resistor as mentioned above. Interestingly, this may be the source of the humming you mentioned, esp. if the blower is on "1", "2", or "3" and fan not blowing at the time.

2. Overheating issue, sounds like it could be the engine fan clutch. The fan might be spinning but not pushing alot of air when engine is very warm or hot. Of course this is assuming that the coolant level is up. Also, might check the auxillary fan operation when you turn the AC on the aux fan in front of the radiator should come on as well, assisting in cooling while running the AC.

3. The outside temperature sensor might be faulty if you're getting that chime/bong and it reads some negative/cold temperature. The sensor is typically located in the front grill area next to the driver's side (LHD cars) foglight. It is in the little hole with the black plastic stick sticking out (the black stick being the end of the sensor). It is usually the wiring that is bad and not the sensor itself, by the way.

Definately visit Bruno's site for many good fixes and information on E34 issues, including the first two of the above. http://www.bmwe34.net/

Good luck,
JonE

[CharlesAFerg]

Alright! I finally got some answers form my mechanic and you were right about the sword! I need a new one of those and I ordered it!

The front sensor also needed replacing, it was broken or something, kept reading that it was freezing outside, lol. (95* day w overheading car, sweet)

They still don't know why it wont start sometimes, because for some reason it decided to start every time at the shop by not for 3 days at my house so they couldn't diagnose it.

The cooling problem is apperently either a thermostat causing the water to not circulate enough, so my pump is fine apperently, its jsut the computers fault for being old and stupid. I gues i got a new thermostat, but it was bad, thats why I was so confused.

I guess the other AC problem is the "blower motor resistor" I'm still looking for one (any ideas?)

Anyways, thanks for the help, but if anyone has had this wierd starting problem and if there is some way to test if its the fuel air or electrical, pelase tell me, because my mechanics apperently cant figure it out. (Motorsports international in Oregon, very good)
Thanks!
-Charles

[Beemr750]

Your starting problem could originate in the ign sw.While cranking and no start, check treminal #15 or + on the coil for power.If no reading, could be bad contact in ign sw.

[pundit]

...When you turn on the ignition and all of the electrical BEFORE the car STARTS, I get this buzz and vibration coming from inside the dash near the AC and radio, basically high center. I know there is always a buzz AFTER the car is SHUT OFF on most e34s in the same area, but this buzz is louder, it rattles, and it doesnt stop after 20 seconds or however long the other one lasts. This continues until you turn the electrical off...
There are three sources of interesting noises that eminate from behind the dash of our E34's.

1. Heater valve solenoids. Always fully on with no power applied. Progressively turned off as power is applied. When the ignition is first turned on (with heater control set to off) these will make a slight noise as they shutoff.

2. Stepper motors for climate control air vents. (Up to ten of these are fitted in cars with full climate control) These will reposition each time they are powered down and up. These tend to make a ticking sound.

3. The daddy of them all. The windshield wiper pre-tensioner motor. This is the rather loud whirring/buzzing noise that appears to come from somewhere behind the instrument cluster. Usually begins within about 10-20 secs of starting the engine. Noise lasts 5-10 secs. Makes the exact same noise within about 5 secs of shutdown. If you put your hand on the drivers side wiper spindle you can feel it.