2000 BMW Z3 My Z3 stalls and sputters once warm

2000_Z3

MEMBER
2000 BMW Z3
6 CYL
2WD
MANUAL
62,400 MILES

I just bought a used Z3, which drove fine for the first 2 days (about 50 miles). Then, it happened to be pouring rain (not sure if that matters) when the engine seemed slow to respond when I gave it gas, and I noticed the "Service engine soon, " light was on. My cousin plugged it into his diagnostic equip, and it said something to the effect of "chip miscalculation." He reset the SES light, and it ran fine for a day. It seems to stall or sputter or be sluggish when: the oil temp is up to normal range (seems fine when cold); RPM is between 1 and 2K, after shifting into 2, 3, 4th or 5th gears. The SES light is back on. I've seen a number of posts with similar characteristics, and varied suggestions. The only people who posted after repairs (to let us know what the solution actually was) were people who replaced the coils (which seems to work). Any suggestions, especially any successful solutions? Thanks!

1 Reply

BUDDYCRAIGG

MECHANIC
2,262 POSTS

Well.
Weak coils can have a "cold" spark, I mean the spark isn't hot enough to ignite the fuel mixture correctly.

Humidity (or rain) can effect ignition components

failing electronics can often seem to work ok when they are cold, but as the engine warms up the failing part starts to get worse. Often with coils and ignition modules.

And you've got people posting on the internet that they have solved their problem with new coils.

I say go for the coils

if it looks like a duck,
acts like a duck,
quacks like a duck,
and people tell you it's a duck.
Well.
It's probably a duck.

Good duck,

I mean luck