No crank, no start.

e91Owner · 10-30-2025, 09:25 AM

Quote:

Originally Posted by SyncVox

I have the same problem, and first thing I would recommend all to do is to check the connection from the battery to the engine. For me it's the lack of ground, but the main ground cable is good. Have to check why it's not going from the engine mount to the engine.

Are you saying that when you check the voltage between the + terminal in the engine bay and the block, it is reading 0? If that is the case, manually bond the block to the - stub in the bay with a jumper cable & attempt a restart. If that does work, your ground is no bueno.

BMW man · 11-28-2025, 09:32 AM

Hi All. My son recently had this issue. We quickly verified that by pushing it down the road and jump starting it by engaging 2nd gear once some momentum was reached, the car started and ran fine. So did not appear to be an engine related issue at this stage. Like everyone else I jumped on YouTube etc and diagnosed a few things without success. I even took off the starter motor assembly, hooked it up to a spar battery for test purposes and in my case, worked fine. Here is what I eventually found in my case. On his BMW 320d the battery cable comes from the back, and is fed through the car. With the bonnet open and with the plastic engine cover removed, you can see that it runs from right to left across the top of the engine bulkhead nearer the wipers. This cable (very thick and carries the positive voltage) comes out of the plastic cover and is seen to go into a small covered junction just behind the windscreen washer container. Remove the plastic cover off that junction (ease it off gently with a flat blade screwdriver) and you will see that the thick cable terminates onto a metal bracket that is bolted in position by a Ny lock (or similar) nut. The other side of that metal bracket is also terminated by a thick cable which continues down and is the main cable that carries the positive voltage and is eventually bolted to the starter motor main power terminal. Going back to that Ny lock nut, on my sons car it looked like it had overheated because the nylon within the nut had melted. It was dark out when I was diagnosing this area and I noticed that if I moved that area I would observe some sort of arching/spark. The solution for me was to remove that Ny lock nut which released the thick cable, I cleaned the mating faces of the metal bracket thing as well as where it was bolted to, then refitted the assembly back together, and the starting issue was fixed. So I assume the issue in my case was caused by a loose nut which allowed arching which eventually corroded the junction enough to affect the high current draw during the starting process. The car has been fine since. A lot of focus is given to the earthing side but in my case it was the positive side. An easy fix. I will include pictures. I do hope that this info will help some of you out there. Good luck.

sonofsun · 11-28-2025, 04:27 PM

Great handsketch. Bravo.

TurboTye · 01-26-2026, 12:41 PM

I'm glad to have found this thread. My 2007 328i just decided on Saturday to have a no crank situation. My starter has always been VERY slow to turn on anything colder than -10C, and in this situation, it was -25C. I boosted the car, and did a quick charge on the battery, and was able to get it to start to go out. Later on that night, it was -30C and I didn't even get a click out of it. Battery was fine, no dimming of lights or anything when pressing start, just no action whatsoever from the starter. It's manual and I was able to bump-start it to get it home. Fired right up bumping in second gear.

I have long suspected that there was higher than normal amp draw due to the long run of cable from the trunk to the engine compartment, but now I have a bunch of other things to look at.

Accessories all come on and work but I'm definitely going to check under the battery and at that positive terminal for corrosion, etc. I'll also have to test that ground strap situation.

Lots of other things to check, but I feel like this one is a simple fix. Very low mileage for its age, but corrosion doesn't care about mileage, haha. 144000kms on this one, but it's 19 years old, so...

11-28-2025, 09:32 AM	#46
BMW man Registered 3 Rep 1 Posts Drives: BMW 120 D 2011 Join Date: Jan 2024 Location: Buckinghamshire iTrader: (0)	No crank no start - fixed - 2008 320d manual version- Bad Positive supply Hi All. My son recently had this issue. We quickly verified that by pushing it down the road and jump starting it by engaging 2nd gear once some momentum was reached, the car started and ran fine. So did not appear to be an engine related issue at this stage. Like everyone else I jumped on YouTube etc and diagnosed a few things without success. I even took off the starter motor assembly, hooked it up to a spar battery for test purposes and in my case, worked fine. Here is what I eventually found in my case. On his BMW 320d the battery cable comes from the back, and is fed through the car. With the bonnet open and with the plastic engine cover removed, you can see that it runs from right to left across the top of the engine bulkhead nearer the wipers. This cable (very thick and carries the positive voltage) comes out of the plastic cover and is seen to go into a small covered junction just behind the windscreen washer container. Remove the plastic cover off that junction (ease it off gently with a flat blade screwdriver) and you will see that the thick cable terminates onto a metal bracket that is bolted in position by a Ny lock (or similar) nut. The other side of that metal bracket is also terminated by a thick cable which continues down and is the main cable that carries the positive voltage and is eventually bolted to the starter motor main power terminal. Going back to that Ny lock nut, on my sons car it looked like it had overheated because the nylon within the nut had melted. It was dark out when I was diagnosing this area and I noticed that if I moved that area I would observe some sort of arching/spark. The solution for me was to remove that Ny lock nut which released the thick cable, I cleaned the mating faces of the metal bracket thing as well as where it was bolted to, then refitted the assembly back together, and the starting issue was fixed. So I assume the issue in my case was caused by a loose nut which allowed arching which eventually corroded the junction enough to affect the high current draw during the starting process. The car has been fine since. A lot of focus is given to the earthing side but in my case it was the positive side. An easy fix. I will include pictures. I do hope that this info will help some of you out there. Good luck. Attached Images
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11-28-2025, 04:27 PM	#47
sonofsun Lieutenant 306 Rep 405 Posts Drives: '11 328i X-drive E90 N51 PK53 Join Date: Nov 2017 Location: Texas iTrader: (0)	Great handsketch. Bravo.
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01-26-2026, 12:41 PM	#48
TurboTye Registered 3 Rep 3 Posts Drives: E90 328i RWD 6MT Join Date: Feb 2025 Location: Ottawa iTrader: (0)	I'm glad to have found this thread. My 2007 328i just decided on Saturday to have a no crank situation. My starter has always been VERY slow to turn on anything colder than -10C, and in this situation, it was -25C. I boosted the car, and did a quick charge on the battery, and was able to get it to start to go out. Later on that night, it was -30C and I didn't even get a click out of it. Battery was fine, no dimming of lights or anything when pressing start, just no action whatsoever from the starter. It's manual and I was able to bump-start it to get it home. Fired right up bumping in second gear. I have long suspected that there was higher than normal amp draw due to the long run of cable from the trunk to the engine compartment, but now I have a bunch of other things to look at. Accessories all come on and work but I'm definitely going to check under the battery and at that positive terminal for corrosion, etc. I'll also have to test that ground strap situation. Lots of other things to check, but I feel like this one is a simple fix. Very low mileage for its age, but corrosion doesn't care about mileage, haha. 144000kms on this one, but it's 19 years old, so...
	Appreciate 0 Quote