miguex

Do you think the spark#7 has Oil deposits or Gap bridging?

I will bring them to my independent BMW mechanic on Monday and see what they say.

andy545

Dig up some of my posts - my engine was replaced couple of years ago due to the "ticking noise" - ended up being an out of tolerance cylinder...guess which one ? : no.7

oil deposit on the 7 spark plug doesn't sound like a coincidence to me.

get it checked.

miguex

That is interesting.... Number 7 is a bad number eh?....

Yes, I will check it in a few days then will post the status.

baadaaboo

this problem wouldn't happen to 6 cylinder right?

EBMCS03

I was just going to post I should have bought a 6 cylinder!

my530i

Still have on 6-cyl as the pattern is # of cylinders - 1. If you have I6, check the 5th one

pentiumpush

From the pictures, it doesn't appear that oil deposits have formed on the cylinder number 7 spark plug. It looks more like carbon buildup. Either the other ignition components for that cylinder are not quite up to par or the fuel injector is slightly clogged. I would test the impedance of the coil and the resistance of the wire (if applicable). If they are within factory specs. then just run a bottle of fuel injector cleaner through a full tank of gas and see what happens.

06530-6M

Honestly, my first reaction to your photos was surprise at how much build-up was on ALL of your plugs. When I replaced mine on my E39 at 90,000 miles I remember how clean they were. Sure, not all nice and shiny like the brand new ones going in, but my mechanic remarked at how good they looked with regard to their age. There really was no build-up of any kind anywhere on them -- they just looked 'older.'

My question to you is what kind of fuel have you been using on a regular basis, and perhaps more importantly, is it a major, good quality brand of gas? Trust me, it DOES make a definite difference. I read articles years ago about the 'cheap' brands vs. the major brands and have always stayed away from them. For me, it's always Hess or Chevron.

Another point, and perhaps I should open this as a new post: My SA was counseling me the other day to never let my gas tank go more than 3/4 empty, i.e. I should consider a 1/4 of a tank as 'empty.' They are very concerned about the amount of ethanol that's being put into our premium gas and believe it is too-often more than the legal amount of 10% despite what's displayed on the tanks. He tried to describe to me how the E60's fuel pump sort of sits in a 'coffee can' type apparatus and because ethanol is heavier than gas, it tends to collect at the bottom of the tank where the pump is located. When you allow your tank to go all the way to empty, it's basically 'swimming' in too much ethanol, or at least a higher ratio than what's good for the engine, fuel pump, and spark plugs.

If you can't tell, I'm anything but mechanically minded. Perhaps some of you who are more versed on this topic can chime in with better descriptions and/or advice?

MRV99

Well the only way that I can see this being supported is that ethanol is hygroscopic - it attracts water, and can even pull it in out of the moisture in the air. If the moisture does get into the fuel, it will mix with the ethanol and settle out. From what I can deduce from this, is that no matter what you do the ethanol will settle to the bottom every night when your car just sits in the garage. So every morning the bottom of the tank would be ethanol and water. So the 1/4 = empty does not really fly with me.

If this IS the case then somebody should find out how gas stations pump gas from the tanks to the dispenser. If they pump for the top then you want to fill up around the day which they fill the tank stations tanks. If it is from the bottom, you want to wait until the stations tank has been drained more and the full station tank people filling up would have very large quantites of ethanol and watter and the near empty fillers would have little or no ethanol in the tank.

southgate

wow i have to pull mines out n check them out to see what condition they are in!!

MIGUEX did you have to reset the Idrive????? or did any warning come up???