shearoth

About 2 months ago i began having some issues starting my car it will crank but not start. This only began happening when the temperature began dropping and also has only happened later at night and will always start right up the next morning, not sure whether thats coincidence or if that could be some clue to whats going on. I've checked the fuel pressure and there doesnt seem to be any problem with the fuel pump and i had spark plugs replaced about ~1500 miles ago. I was getting a crankshaft sensor code so i replaced the sensor but that also didnt solve the problem and i am not sure where to look next, if anyone has had this issue themselves or has any idea what could be causing this i would appreciate any advice i can get at this point.

seanjordan20

Fuel, air and spark is what you should be checking. I'm sure your car had more codes than a sensor error. How are you checking for codes. If your not using something specific to BMW of a beefy OBD2 reader then you need to either go that route or take it in for a diagnostic. Your car cranking but not starting would through a codes to the module even if it doesn't illuminate the check engine light. Find out what those errors are and I'm sure you'll find your way to the issue

scottalexander

Here's the long crank no start project plan I put together over the last several years using the forum members suggestions.

The diagnostic plan (attached) is for my e60, but should be somewhat similar for you.

shearoth

My friend has a pretty beefy obd2 reader that i have been using and i was getting some vanos codes as well as a cylinder 2 coil code but i dont believe that either of those would be causing this but i’ll definitely go ahead and scan it again and double check that im not missing something

seanjordan20

Ok let us know what you come up with.

shearoth

Lots of new ideas to check out from that thanks for sharing

shearoth

Ended up getting a lot of new codes but every single one was voltage related. I also found out the main cause is the DME isnt getting any crank signal from the sensor that i replaced so im going to reinstall that new sensor after cleaning the slot and hope that helps. we also tried taking out the DME and heating it up but got no results from that either. So if cleaning that sensor slot doesnt change anything we know that somewhere between the sensor and the DME that crankshaft signal is getting lost, so we at least have some direction to go towards now.