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e85 n52 3.0 rough running ( spark plugs, vani, valve gasket )

Discuss problems you have had or are having with your Z4
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rhetoric
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e85 n52 3.0 rough running ( spark plugs, vani, valve gasket )

Post by rhetoric » Mon Feb 19, 2018 9:22 pm

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.

DJz4
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e85 n52 3.0 rough running ( spark plugs, vani, valve gasket )

Post by DJz4 » Fri Feb 23, 2018 9:28 pm

Thanks - I will take a look at mine :thumbsup:
BMW E86

AveZ4coop
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e85 n52 3.0 rough running ( spark plugs, vani, valve gasket )

Post by AveZ4coop » Thu Mar 01, 2018 3:10 am

Had the same problem on my Z4C. Replaced all the coils and plugs due to engine warning light/lumpy running and after replacement I had a horrendous misfire. Noticed a couple of coil packs about 2-3mm higher than the others, pushed them down and problem solved. The later replacement Bosch coils don't give a 'click' when you remove or refit them like the originals do to let you know they are fully 'home'. Has now been running sweet as a nut for a few months.
Montego blue 2006 BMW Z4 coupe 3.0si with black interior, ZHP, Whippy, 12mm front/16mm rear spacers on BBS 108's wrapped in Michelin PS4's. :driving:Brand new Pierburg water pump fitted at 101k after failure :cry: (should have done it at 100k) :headbang:

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