[snaeem155]

Hi all,

Recently changed all my coilpacks to Delphi 10572's and OEM Bosch spark plugs.

On idle the car shakes considerably and the voltage measured through the OBD is all over the shop going from 11.9 to 13.8v.

Also noticed my glovebox light dimming in time with the shuddering.

A new alternator was fitted by BMW 7 months ago along with a new battery.

Only mod is MHD stage 1+ and I get no fault codes whatsoever.

Reading online that I may have fake Delphis? (black epoxy instead of white).

Any ideas?

[Saif2018]

Originally Posted by snaeem155

Hi all,

Recently changed all my coilpacks to Delphi 10572's and OEM Bosch spark plugs.

On idle the car shakes considerably and the voltage measured through the OBD is all over the shop going from 11.9 to 13.8v.

Also noticed my glovebox light dimming in time with the shuddering.

A new alternator was fitted by BMW 7 months ago along with a new battery.

Only mod is MHD stage 1+ and I get no fault codes whatsoever.

Reading online that I may have fake Delphis? (black epoxy instead of white).

Any ideas?

Have you checked the voltage at the battery directly?

Also where did you get the coils from?

Whats your idle speed?

[snaeem155]

Haven't checked the voltage at the battery yet.

Got the coils off of Amazon, sold by Amazon and not a third party.

Idle is around 630-660rpm.

[Saif2018]

Originally Posted by snaeem155

Haven't checked the voltage at the battery yet.

Got the coils off of Amazon, sold by Amazon and not a third party.

Idle is around 630-660rpm.

Dunno if this is gonna make a difference but try adjusting idle speed to 700rpm or 750rpm using MHD options, I had mine adjusted to 750 rpm for ages, runs smooth.

Also check the battery voltage directly if that doesn't make a difference.

If you had a good set of coils, you could have swap them out to check.

[snaeem155]

I'll adjust the idle today and measure the voltage at the battery and see how I fare.

The coils are probably less than 150 miles old, blew one of the OEM Bosch ones soon as mapped stage 1 hence the replacement.

The juddering is deffo worse after installing new spark plugs.

[Saif2018]

Originally Posted by snaeem155

I'll adjust the idle today and measure the voltage at the battery and see how I fare.

The coils are probably less than 150 miles old, blew one of the OEM Bosch ones soon as mapped stage 1 hence the replacement.

The juddering is deffo worse after installing new spark plugs.

OEM Bosch plugs should easily handle stage 1+, shouldn't cause any juddering or misfires.

Let us know what happens when you try the above.

[snaeem155]

If it helps I just did an idle log with a few seconds holding it at 1krpm.

https://datazap.me/u/snaeem155/idle?log=0&data=1-12

On starting the ignition the battery voltage was at 11.17v.

Its a new battery not even 7 months old.