New 928 owner
 

So wear do I start. I have been eyeballing this BMW 540it for a while and the person who owns it has cancer. I have trying to buy it but he has been unrealistic on his price. Well the person that has power of attorney call me and asked me to come and look at the car again. He has four cars that need to be moved and go away. The long a short of it he gave me three of the four cars if I could get them gone in the next day. One just happen to be a 87 928s4. Hasn't run in two years. I'm sure even free, this car is going to cost me money and lost of it. There is oil on the coolant and water in the oil. I have been told I might get lucky and it is just a bad radiator. I'm hoping that it isn't head gaskets. I started by adding gas and a new battery and the gas all pored out onto the floor. So I'm starting at the back and working my way forward, I have the gas tank out and new hoses and fuel pump on it's way. The other problem is that under the glove box it looked like a scene out of horror movie. He added these devises that made the windows and sunroof one touch, alarm and a stereo that would bring down the house. Wires, amps and speakers everywhere. It was a old system so I tore it all out. I think between three amps and all the wire, I think the car just lost 30 pounds. My biggest problem is that once I removed the the one touch window things the windows don't work anymore. I have power at the switch and I tested the switches and they seemed to be working as they should. So after a long story does anyone have a thought about the windows?

Buy a membership first, and post some pictures. Plus let us know where you're located, in the real world, or some 3rd world rat hole. It makes a difference!

You'll get all the help ya need!

Ok, here is a photo
 

https://cimg7.ibsrv.net/gimg/rennlis...5531658eda.jpg
I did join and here is a photo. I live in San Luis Obispo,CA

Car looks nice. Sounds like the after market alarm is the culprit. Electrical isn't my strong suit. I'm more the mechanical type.

There are some of the most knowledgeable 928 owners located near you. You'll get help, but it's Sunday night. Tomorrow the opinions will start coming in. Some pictures of the wiring where all the items you removed would help out too.

Welcome to the ocean! Read the " New Visitor" section at the top section of the 928 forum. Lots of great info.

Welcome.

Windows, start with relay 3, and fuse 15. Make sure they are ok. The relay can't be swapped with others. You can take it out and test it, or swap with another car. check the fuse in 15.

There is also a window motor controller in the center console, and some wires that lead to the switches. If you have power at the switch, may be the controller.

some links:

http://www.928intl.com/repair/Relay/earlyrelay2.htm

https://members.rennlist.com/v1uhoh/windowSW.htm

You don't have to join to get help, and just because you joined doesn't guarantee that you will solve your issue, it can be a great site, great score on the car.there is a lot of info here and it's free, cheers.

Welcome to the group :) you will get tonnes of help here.

First, check the wiring. I'm sure that the window controllers were spliced in and intercepted the signal from the switches.

You are going to need to find both ends of the spliced wire and either solder or crimp them back together using spade or bullet connectors. Whichever you prefer.

Added systems like yours are common to these cars, especially of the UNGO box variety.

Best of luck getting it running again.

Welcome! There are cheap 928's out there but non are cheap to run and some are horror stories so if you got yours for free put $10k aside to deal with it and if you do not use that consider yourself lucky!

As a new owner you should first of all read the thread for newcomers in the Admin section.

On the plus side the first photo you submitted looks promising so that is always a good sign.

The windows are the least of your problems and if they are open and you need them closed then you can always pull the door trim and set them manually by disengaging the lifting mechanism and setting the windows closed manually.

As per your initial issues if fuel is pouring out then obviously you need to find out where it is coming from.

If you have oil in the coolant and vice versa then this is probably caused by a leak in the radiator end tank cooling coil located on the driver's side. Later models eliminated this feature by using a separate air cooler located under the radiator. If there is a leak path, when the engine is running the oil pressure is much higher so oil can migrate into the cooling system and this should not cause any harm as ultimately the expansion tank cap will lift and blow out any excess pressure. When the engine is switched off the oil pressure drops immediately and then the cooling system is at a higher pressure and the cooling system will tend to equalise by blowing coolant into the oil system- not good! Whether such has caused any problems remains to be seen.

At this age head gaskets are also a potential issue especially if the car has sat still for a long period and this can also cause corrosion issues around the sealing surfaces.

Chasing out electrical problems caused by DIY hacks at best is fun and can reduce grown men to tears!

The 928 does not like to stand idle and the list of things you should check and expect to replace is extensive. The cam belt is the first suspect, especially if you have no history of when it was last replaced. you would do well to change this before thinking of trying to fire up the motor and a new water pump usually goes with a new belt if the age/mileage is not known.

There are plenty of other things you should inspect and possibly replace before firing up the motor. Besides the above, you should check that the motor can spin freely and also good to check the crank end float to eliminate a condition known as TBF [look this up in the search engine].

First of all post some more pics including the engine bay and areas you have known problems with.

Update to my 928
 

https://cimg8.ibsrv.net/gimg/rennlis...07b1cdc2a8.jpg

Here is all the aftermarket wiring that I removed from the car.
I'm waiting for new parts for the fuel tank and the cage that holds up the fuel tank to be powder coated before I can fire it up.

The windows are the current mystery. I removed the aftermarket alarm and the aftermarket one touch window controllers. They where spliced into the window switch wires, I reconnected all of the wires like they should be. I have power to the relays, but the windows don't work. I think they must have bypassed the relay with with one of the many relays that I removed in all of this extra wiring. Here is a photo of it. I will find the problem with the windows, it is going to take some time.

What a mess! These cars have a factory alarm. For the life of me I can't figure out why anyone would install an aftermarket alarm.

These cars are fantastic as is. I supercharged mine, but that a performance upgrade.

Good luck!

I forgot to mention the three huge amps that where mounted in the rear deck. I just want to return it to stock.

I can't find the window motor controller in the center console.

I may be wrong, but I think is a black box located under the driver's seat.

on a 87 S4, I don't see anything under the drivers seat that looks like that.

It doesn't show on my service manual disk ether. Sorry