2003 E85 starts and runs, then doesn't start.

[240russian]

Hello everyone! New here, figured I would try the forums.

Last year I bought a 2003 E85 2.5 5 speed manual with 80k miles. I'm somewhat versed in the early 2000s BMWs. I've owned several E46's. New to this platform. I bought it as a little project to "restore"/fix. The car started and ran great when purchased. Drove it 2 hours home and drove for a couple days. The car did not have a CEL on, but definitely had stored faults as well as the trifecta lights for the traction/abs system. As well as the airbag light. Once summer came to an end I parked it in the garage and started ordering what I needed to fix said problems.

I want to make this short but it seems like I need to be as detailed as possible. The car definitely had water get into it as there was obvious signs. I ripped out the entire interior excluding the dash. Carpets, seats every trim taken out to try and clean any water damage/corrosion. I also took the entire top off also as im planning on rebuilding it. Just havent gotten to it yet. After further research/diag I found out the YAW sensor went out from water getting into under the carpet from the passenger door trim. I replaced the sensor and the trifecta of lights disappeared. Boy was I happy to see that. Next I noticed water got into the main airbag module that sits in the middle console towards the back of the car, that made my car freak out. Half of the instrument lights did not work. No chimes, dings, etc.. I unplugged that module and now everything on the instrument cluster works as it should. I believe that module is tied into the kbus. So at this point everything is fixed(besides the airbag light because of the module). Car starts, runs great. I did a couple of things under the hood, ofhg, vcg, opg, deleted secondary air pump, all new cooling system. Basically freshened up the entire engine and components because it was leaking quite a bit. Now she's leak free and you couldn't ever tell it leaked anything.

Anyways that was this past winter. Going forward to now. I haven't driven or started the car for almost 2 months. I did not have the battery on a tender, but I did have the negative post unplugged. Plugged the battery back to the car to get it out to clean the garage and get the fluids flowing. Car starts immediately without hesitation. Sounds good. I drive it maybe 6ish miles to get gas and get the fluids flowing. Car drove fine. No hesitation. Power is all there. No lights on the dash besides the airbag light. When I pull back into my driveway I leave the car there, turned it off. Cleaned the garage. Once I was ready to pull the car back in, it just cranked and cranked but never turned over. It cranked fast no signs of it ever slowing down. Checked battery, it was good. Ended up pushing the car in the garage. 2 days go by. I go out to try and start the car and it starts up immediately with no hesitation. At this point I'm lost. I did replace the ignition switch a few months ago also. I know just reading this won't be much help. I will try and get whatever codes/faults I have stored in the car asap.

I do have a bmw specific code reader. It's nothing fancy but it will read the car. I don't remember the codes specifically but once I have time I will plug it back in and update this post.

I appreciate you reading this if you made it this far.

Aleks

[enuff_zed]

Welcome to the madhouse.

I've had some experience with the centre airbag module (SIM85) corrupting the kbus, but it sounds like you got that sorted.
When it comes time to replace that you will find all the info you need on here to select an exchangeable part number and code it to the car (VIN and System Time)

Wrt the starting issue I suspect you'll have quite a few things to check: fuel pressure, pump running, spark at the plugs, etc.
The only issue I ever had with those symptoms was due to the EWS not accepting the replacement DME we fitted. The engine turned over fine, but I think the EWS must stop the fuel pump running or something as it would not start.

As you said, get the codes and that'll hopefully guide us a bit better.

[240russian]

Thanks for the reply. I did replace all the spark plugs and ignition coils this past winter also. Just about everything I've replaced has been through fcpeuro. Thank goodness for lifetime warranty if anything fails. I feel like it might be ews related. There isn't any signs of water getting Into the dme last time I checked. I read somewhere to check those 5 fuses in the little box next to the dme. Although if it was a fuse I wouldn't think the car would just start 2 days later. The dme is original to the car. Someone else told me it could potentionally be the fuel pump. When my fuel pump went out in my e46 it was abrupt. No symptoms just poof.

Just writing this all out while it's fresh on my mind and visiting what you wrote also. I'll try to get my scanner on the car within the next couple days.

[Rockhopper]

The failure to start you are describing sounds like the classic symptoms of a failing crank position sensor. When it gets hot it fails but starts working when it cools down again. My Alfa has this issue and interestingly it didn’t turn the light on.

[240russian]

The failure to start you are describing sounds like the classic symptoms of a failing crank position sensor. When it gets hot it fails but starts working when it cools down again. My Alfa has this issue and interestingly it didn’t turn the light on.

Thanks for the reply. This just made me remember something when I was trying to crank it that day. The car never over heated but it did get to operating temperature.
The weird part is, when I was trying to crank it the temp Guage went all the way to the red pinned. That was confusing for sure. The car sat off for atleast an hour when that happened, but regardless it never overheated. Something is communicating with something and was telling me the car was hot.

That's a sign of a bad crankshaft sensor?

[Rockhopper]

Nope!