I have a solution that I haven't seen on other threads... posting for anyone who can't track down a rough running motor ( N52 on my 2007 Z4 w/ 120K ) after doing some basic work...
I replaced my leaky valve cover, changed the spark plugs, cleaned up the vanoses (vani?), and etc. Once I buckled it all back up it ran rough.
When I was getting started and was removing my coil plugs, I noticed that some of them slid right off when I released the top lever. They are designed to (as you lift them) catch a tab on the plastic plug and slide it out. I didn't think anything of it but a couple of my levers were a bit splayed so they didn't catch -- i had to pick and pull a couple plugs off the coils.
Problem/Solution? So when I buckled it all back up those same levers didn't push the plugs back on all the way. 3 plugs were not quite snapped tight to the coils. I didn't notice, of course (they were only separated a couple millimeters) until I fired it up and it ran badly. I squeezed the sides of the levers and re-engaged and problem solved. I'm a little anxious that, splayed as they are, they might not keep the plugs tight, but at least I'll have an idea in the future.
Anyway, I see alot of people really struggling to solve rough running after these basic jobs and I thought I'd let folks know there is another potential hitch in the giddyup.
I replaced my leaky valve cover, changed the spark plugs, cleaned up the vanoses (vani?), and etc. Once I buckled it all back up it ran rough.
When I was getting started and was removing my coil plugs, I noticed that some of them slid right off when I released the top lever. They are designed to (as you lift them) catch a tab on the plastic plug and slide it out. I didn't think anything of it but a couple of my levers were a bit splayed so they didn't catch -- i had to pick and pull a couple plugs off the coils.
Problem/Solution? So when I buckled it all back up those same levers didn't push the plugs back on all the way. 3 plugs were not quite snapped tight to the coils. I didn't notice, of course (they were only separated a couple millimeters) until I fired it up and it ran badly. I squeezed the sides of the levers and re-engaged and problem solved. I'm a little anxious that, splayed as they are, they might not keep the plugs tight, but at least I'll have an idea in the future.
Anyway, I see alot of people really struggling to solve rough running after these basic jobs and I thought I'd let folks know there is another potential hitch in the giddyup.
