Oil on the electrode side of the spark plugs!

[jac]

So I think it is likely the coil. I must have screwed up which coil was which when I did the coil swap initially because the issue moved cylinders this time.

I have ordered new coils. I'll let you know what happens when they get here.

[jac]

And.... It was indeed a bad coil.

Car purring nicely now and all errors cleared up.

Thanks all for your help!

[X5only]

Originally Posted by jac

And.... It was indeed a bad coil.

Car purring nicely now and all errors cleared up.

Thanks all for your help!

Now that's what I call meticulous troubleshooting - well done! And thanks for the update . My coils are still original. No troubles but I should probably change them now that the vehicle has hit 130k miles. What's your current mileage?

[jac]

Originally Posted by X5only

No troubles but I should probably change them now that the vehicle has hit 130k miles. What's your current mileage?

130K? That's brand new!

I have had mine since it first came off the lot... It now has 256k miles!

[Homerlovesbeer]

Good news, glad you fixed the issue.

[StephenVA]

Hopefully you up graded the plugs installed.
2.5/2.8/3.0
Iridium IX Part No. BKR6EIX, Stock No 6418, Plug gap .032”

spark plug connectors are BERU brand..if so they are per the spec noted below...1.8Kohm +/- 20%.

Coils should be .8 ohms between pin 1 and 15 (outer pins)...try a lower ohm setting on your multimeter and read them again, but these too seem to be in spec. limits.

Bad ignition coils will give you a SES light. The SES light / OBDII code will point right to the bad one.

Start with ensuring power to your ignition connector - pin 15 should have 12 volts...not fused so be careful while probing.

to test ignition coil primary resistance you can probe terminal 1 (-) and 15 (+)..and you should read approx 0.8 ohms.

to test spark plug connector resistance the Bosch should read 1Kohm +/-20%.
BERU brand should read 1.8K ohm resistance.

Ref. section 120 of Bentley's manual...pin one and 15 are the two outer pins of the three prong connector..4A is the middle pin

Replace the plug boots as they are just a short plug wire that lives in one hot area. You do have the old style square coils correct?

[StephenVA]

^ good thinking!

[StephenVA]

The 3199 BKREQUP plugs are the multiprong plugs that were popular in 2000. Every manufacturer spoke about the ability of multiple ground straps (Prongs) would provide long life which they did compared to single ones. Technology moved on to fine wire plugs with center electrodes with precious metals that provide better idle stability/ignitability characteristics for lean conditions, better tip in acceleration, and better fuel economy.

Take a look at the Iridium IX - Part No. BKR6EIX, Stock No 6418, Plug gap .032”

https://ngksparkplugs.com/en/product...um-spark-plugs

[nick325xit 5spd]

Originally Posted by StephenVA

The 3199 BKREQUP plugs are the multiprong plugs that were popular in 2000. Every manufacturer spoke about the ability of multiple ground straps (Prongs) would provide long life which they did compared to single ones. Technology moved on to fine wire plugs with center electrodes with precious metals that provide better idle stability/ignitability characteristics for lean conditions, better tip in acceleration, and better fuel economy.

Take a look at the Iridium IX - Part No. BKR6EIX, Stock No 6418, Plug gap .032”

https://ngksparkplugs.com/en/product...um-spark-plugs

Personally, I prefer to just run the copper plugs (BKR6E) and change them out frequently. Especially on these higher mile cars that probably have some blow by. Long lasting plugs aren't that long lasting when the car makes them crusty.

There are exceptions to this. The S65 in my E90 M3, for example, does knock sensing through the spark plugs through some kind of bizarre sorcery. If you don't keep the plugs fresh (max 30k miles, preferably less), you'll lose a ton of power. And you can't swap to alternate plugs without dyno testing.

[stiubhartach]

Oil on the electrodes means oil in the cylinder which can come from three problems.
1. Oil in the intake manifold from a malfunctioning CCV system
2. Valve stem seals leaking
3. Piston rings leaking

Start at the easiest to check and work your way down (#1, #3, then #2)
A. Look in the intake manifold for oil (fiber optic camera)
B. Compression test to check rings
C. If the two above don’t show problems, then it’s probably valve stem seals