Hi all, relative newbie here, hoping you guys can help with a bit of detective work - this forum has already been super helpful, and I haven't even posted yet!

The back-story is that I bought a sketchy e60 without service records. Silly, I know - but it was cheap! The car has 185,000kms on it, and looks really clean inside and out. Love the brown leather interior! I'm not new to fixing cars (though I haven't had many BMW's, and this is my first e60), but this one has me at a bit of a loss. Like the title says, this is a 2007 530xi (N52 engine, type code NF73, build date Nov 2006 for USA market - it's in Canada now).

My issue is a stubborn cylinder 5 misfire that I just can't chase down. I started with the obvious and cheap; I cleaned the vanos solenoids (even though no vanos codes), replaced all spark plugs with the NGK ones for this car (I even checked the plug gaps, though none of them needed adjusting; they all seem to be gapped to 0.043), then I swapped the ignition coil with another cylinder, still misfiring on cylinder 5. Then I figured maybe fuel, so I pulled the injectors and swapped #5 with #2, but the misfire stayed with Cyl 5. Then I checked for compression - and as scared as I was that there'd be nothing on cyl 5, it was surprisingly slightly higher compression. Who knew?

Then I started checking for vacuum leaks; first the lazy way with a running engine and carb cleaner in a spray can, then properly disassembled the intake to inspect pieces. While in there, I checked the DISA, and voila! Disintegrated. Ugh. So off came the intake manifold and found the pieces (yay!). Installed a new DISA (I replaced both, while I was in there, even thought the inner/right looked fine), and hoped that would be it - after sorting out the giant, scary snake nest that BMW calls a wiring harness, back together it went. On the up side, it runs! On the downside, it's still rough. On the other up side, I had no power steering before I started, and with the intake off I saw a plug that wasn't plugged in, so now I have adaptive steering!

I'm hoping someone can steer me in the right direction - my next thought is wiring, to see if cylinder 5 is actually getting a spark. Any thoughts on how to check that properly? Should I be looking for something else? Thanks in advance for any insight, hopefully I've passed on enough detail!

 

Someone had the same issue you were having and replaced all the plugs and coils and it fix there issue. He was troubleshooting for a couple weeks doing the same thing you did and went back to were he started and it worked. Maybe replacing your coils will fix your issue.

 

Maybe, I've thought about doing just that - but then if that doesn't work, do I do the same with the injectors? I hate throwing parts at a car and hoping it works - it's a pretty expensive way to fix things sometimes. Is there a way to test the coil with a multimeter?

 

Yes they have videos on google.