Need some help on either a DME or a cam sensor/shaft adjustment

[mooseheadm5]

I am a BMW tech, and here is what I know:
You must have any used DME realligned to your EWS computer by a dealer or an independent shop with an Autologic or GT-1. This can cost a pretty penny if it does not fix your problem. This cam position sensor code can be caused by the sensor itself, or the tone ring on the cam, or improper cam timing. A good tech can scope the signal to see what the car is producing, Ohms will not tell the whole story. I have personally replaced cam position sensors with aftermarket for years, but have started to see the made in China Febi units fail either out of the box or very early. BMW OE only. The resistance can be the same, but if the sensor does not supply the correct signal, no dice. You can try to replace again to see what happens. If that does not work, time to open the valve cover and see what you find.
If you replace the DME, EWS unit, and tape the matching chip to the antenna ring, you will effectively defeat the EWS and allow DME swapping without and problems. You should be able to do this with any 1.9L DME auto or manual.
I have the set of DME, EWS, and chip if you need, perhaps you can borrow them by paying for shipping (both ways if you don't need them) and pay for the set if you need it.

-P

[jtkratzer]

Originally Posted by mooseheadm5

I am a BMW tech, and here is what I know:
You must have any used DME realligned to your EWS computer by a dealer or an independent shop with an Autologic or GT-1. This can cost a pretty penny if it does not fix your problem. This cam position sensor code can be caused by the sensor itself, or the tone ring on the cam, or improper cam timing. A good tech can scope the signal to see what the car is producing, Ohms will not tell the whole story. I have personally replaced cam position sensors with aftermarket for years, but have started to see the made in China Febi units fail either out of the box or very early. BMW OE only. The resistance can be the same, but if the sensor does not supply the correct signal, no dice. You can try to replace again to see what happens. If that does not work, time to open the valve cover and see what you find.
If you replace the DME, EWS unit, and tape the matching chip to the antenna ring, you will effectively defeat the EWS and allow DME swapping without and problems. You should be able to do this with any 1.9L DME auto or manual.
I have the set of DME, EWS, and chip if you need, perhaps you can borrow them by paying for shipping (both ways if you don't need them) and pay for the set if you need it.

-P

I have a manual gearbox, so that isn't the issue. I'm calling to schedule an appointment with the dealer because I have no idea what I'm doing when it comes to most of what you said above. Should I need to replace the DME/anything else, I'll let you all know and whoever has the parts I need, I'll be buying something I suppose.

Thanks for the help. I'll keep you updated.

[jtkratzer]

You guys want to hear something interesting?

The car went to a BMW dealer to diagnose the issue with the voltage and what not with the camshaft position sensor. First things first, the voltage on the wires was 0, 12, and 12 when it should have been 0, 5, and 12. This was the case because the sensor was shorted out. So, after also finding several air leaks and an air hose being used to carry oil, all have been replaced to fix the leaks and proper type of hose for the oil. Car was supposed to be done last Thursday. However, one of the previously mentioned hoses didn't arrive on time. Friday roles around and they are about to install the new camshaft sensor. Can't get it to go in right, something about the part where the sensor mounts to the block being bad...another $2 part, but they can't get it until Monday. Today, I call to find out how things are going. The head tech is having a hard time figuring out why the cam sensor won't install correctly. After a few hours, the head of service calls me and drops a bomb on me....my car has had an engine swap from an M44 to an M42. I bought the car when it was less than 6 years old and around 80,000 miles on the odometer. No way to tell how many miles are on the M42 sitting in my engine bay. The VIN numbers on the car and the DME match and say I should have an M44 in my 1998 car, but the M42 is there and someone working with the M44 DME. The problem we now are facing is that the M42 engine uses an analog camshaft position sensor and the M44 uses a digital sensor. The reason the sensors weren't working before was due to the fact that the wrong sensor was install because the mechanics were going on the VIN numbers not knowing that the wrong engine was sitting in front of them. The sensors for the two engines are different parts, not only in digital/analog, but different sizes. If the analog sensor is tightened too far, the camshaft will hit it and break it, and if it's not in far enough, it can get a signal from the camshaft. Apparently the window is +/- .002" for the sensor to work properly.

So, in the last year, I've found out that someone has removed the bulb in the dashboard to hid the check engine light because of the faults and that someone has done an engine swap. None of which I knew when I bought the car. So, I've put about 60,000 miles on this car while the check engine light should have been on and the car has a default setting when the cam sensor isn't working to keep the engine safe, however, it causes the catalytic converter to go bad much faster than normal.

I called the guy who sold me the car from the dealership to let him know and to find out what they can do to help me out. He said he would talk to the owner and see what he can do. I have a friend that works there who said the owner might take the car off my hands and take care of the rest of the loan and get me a wholesale price on just about any car I want on the lot. Who knows. We'll see what happens.

Any suggestions, thoughts, ideas?

[jtkratzer]

What I find interesting is how much the dealer tried to sway me away from using a used DME should I need to replace the DME (which it doesn't sound like I will have to) because of how complicated it can be with mismatching VIN numbers, the possibility of the dashboard not working, and the possibility of the engine not working at all plus the issues with the ignition and all that. But then here we find I have the original DME which is for an M44 engine and someone has put an M42 engine in it and everything other than the cam sensor has functioned properly. I suppose the computer can adjust with the airflow meter for the 5.26% difference in displacement and not care about the different engine since the operating temperatures and power are nearly identical. There isn't that much of a difference between the engines for the computer to get really messed up.

The service manager told me that the should they not be able to get the analog sensor to work properly after hearing back from the engineering department in Germany, that the car is not going to be repairable within a reasonable cost. I then asked what about changing the DME to a M42 DME to match the computer to the engine and he said it would probably be cheaper to swap the engine back to the M44 because of the wiring harnesses and the different sensors that would need to be replaced.