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Hi Does anyone know of a list or spec sheet somewhere that would tell me what the expected voltage would be for the crankshaft sensor wire. I know the "live" will give around 12 volts depending on the battery charge level. What should the signal wire that goes back to the DME show. I think it should be 4 or 5 volts but I wanted to confirm as I think I may have a wiring issue. I've looked on the wiring diagram and I can't see anywhere that it states what the voltages should be. Be useful to have all the voltages for the different parts written down somewhere so it's easy to refer to. Thanks for your help Simon
dazh90 posted a topic in E28 1982-1988Hey all, So my eta 525e AUTO still refuses to start (from my previous threads). Changed almost all the ignition components, distributor cap, ECU, relays, sensors, etc etc. I still do not have any spark to the plugs hence a healthy turn over but no idle. So, i finally had a look into the bell housing where both the Speed sensor, and the Reference sensor are positioned. Because this was new to me when i first had the problem, i'm going to give as much detail as possible with the hope someone may stumble upon this thread in the future. The Speed and Reference sensors push into the bell housing of the gearbox between the torque converter and the flywheel/ring gear. They are both side by side on the nearside of the car, behind the airbox. They are both connected to the engine harness and these connectors can be accessed by removing the airbox and can be seen attached to the block side by side. Grey connector plugs into the sensor pushed into hole B and the black connector connectors to sensor pushed into hole D. Both sensors are the same part number (12141710668) and are interchangeable but you can not get the connectors confused as they must go to the correct sensor relative to the hole identified by B and D. This is what i can see when i look into the reference sensor hole and a i believe my trigger pin has snapped because everything else has been changed and i get quite funky results when the engine is turned over and a AC Volts are measured across the sensor. See Duncan's amazing guide on how to check this if you do not know already below. MASSIVE thanks to Duncan for this, has helped me and tonnes of other people. So the sensor that i discovered was faulty was the reference sensor, which goes into the hole closest to the road. The lowest hole. This sensor was absolutely shot, it had no resistance so was not detecting anything. I changed it for a working new one which i can confirm works as it was tested in a university lab using an oscilloscope. Correct resistance and AC sine wave replicated by a spinning neodymium magnet. This has not solved my issue so this is what i see when i look into the hole. I need help and peoples experienced opinion on this as its the first time i'm investigating it: Now analysing this photo, reveals to me.... this does not look right. Although it does not look aggressively snapped, it does not look long enough!? The only angle i could take the photo forces it to be taken bias to the front of the engine so you can even see the ring gear. If you look at it from the angle the sensor would read, you can barely see the pin! I've drawn out roughly what you would see if you looked at it head on.. So, does everyone agree that this does not look right? Has my pin snapped or is this normal? As the flywheel rotates, it will not swipe across the sensors face/tip. Also, an interesting observation i made of the old, faulty sensor backs up the theory that the pin has snapped. The old sensor has swollen out creating a dome to its face (interesting?...). There are also scrape marks on its face and a dent to suggest its been grinding against something. Wondering if anyone know about this, if they have changed a flywheel on these cars. As the engine rotates and you pass the trigger pin on the flywheel, you periodically come across large tabs of the flywheel that pass by the sensor which are NOT trigger pins. They are just large areas of the flywheel that match the length of the trigger pin. These have long scratches on them like the rust of the wheel has been removed. Long lines of exposed fresh metal as if the sensors swollen tip has made them. So, that is where i am at currently. What do people think? Is this enough to pull the transmission out and replace the flywheel? Has the trigger pin snapped off? Is this normal what i am showing and if so, where would my next area of investigation be? Is changing both sensors enough to move on and look elsewhere? ALL help and opinions are immensely appreciated, i really am stuck. I also hope some of this information will inspire someone else with the same problem and help them repair their own fault!! Kindest regards, Darren - From Brighton, UK
I hope this should be OK to post here but this post is mainly for those who don't know or are searching the Internet as I couldn't find anything anywhere on the matter not even in the bmw workshop manual. The flywheel locking hole is below the starter motor on the left side of the engine and has a little plastic bung in the hole (mine was yellow). Before attempting to remove the pulley it is advisable to remove the radiator. The crank vibration damper pulley is removed by first undoing the 8 little bolts in the front to remove the Aircon drive pulley. Then the crank bolt itself is a 22 mm socket and is removed in an anti clockwise rotation. It is a right hand thread (like most bolts) and I used a 1.2m breaker bar. Do not use an impact wrench or air ratchet. Once the bolt is removed everything should slip off, it may require a little leverage but only gently whist lightly tapping simultaneously with a rubber mallet. The air-conditioning pump bracket also has to be loosened to remove the lower timing case cover or removed but I had gas in my system so I loosened it off. If your are also removing the cylinder head as well as timing chain, the head bolts are an E12 female torx socket. You will need a minimum 150mm extension bar and a breaker bar this time I used a 400mm bar, it didn't need much force as they are at 30Nm plus a bit more. Do not use an impact wrench or air ratchet as this could shatter the casting, then it's game over. That is all.