Please Help!!! 540i/a running rough

[tim s]

hi,
my 1995 540i/a (180,000mi.) has had a rough idle for about 2 months now & is getting worse. i checked the block number & i have an alusil block. i replaced the plugs & boots. compression tests over 200 in all 8 cylinders. it started with just a rough idle & now it runs rough up thru 1300 & gets semi smooth through 2000. one day it threw a check engine light & i did a stomp test & got a 1213 error(o2 sensor #2). so i replaced both sensors with new o.e. sensors. no difference. it has also lost its edgy power it once had. my mechanic is suspecting clogged fuel injectors. we dumped high quality fuel injection cleaner in. i will find out soon if that will fix it but i am doubtful & frustrated. is there anything i am missing or something else i should be looking at??? i am anxious to install the e.a.t. chip i ordered over the weekend.
thanks
tim s.

1995 540i/a
1987 325e

[Terry B]

hi,
my 1995 540i/a (180,000mi.) has had a rough idle for about 2 months now & is getting worse. i checked the block number & i have an alusil block. i replaced the plugs & boots. compression tests over 200 in all 8 cylinders. it started with just a rough idle & now it runs rough up thru 1300 & gets semi smooth through 2000. one day it threw a check engine light & i did a stomp test & got a 1213 error(o2 sensor #2). so i replaced both sensors with new o.e. sensors. no difference. it has also lost its edgy power it once had. my mechanic is suspecting clogged fuel injectors. we dumped high quality fuel injection cleaner in. i will find out soon if that will fix it but i am doubtful & frustrated. is there anything i am missing or something else i should be looking at??? i am anxious to install the e.a.t. chip i ordered over the weekend.
thanks
tim s.

1995 540i/a
1987 325e

maybe a vacuum leak? The V8's seem to have a problem around the rear of the intake manifold - you might want to look there...

[tim]

The Eat chip improved my idle without doing anything else.

[DueyT]

hi,
my 1995 540i/a (180,000mi.) has had a rough idle for about 2 months now & is getting worse. i checked the block number & i have an alusil block. i replaced the plugs & boots. compression tests over 200 in all 8 cylinders. it started with just a rough idle & now it runs rough up thru 1300 & gets semi smooth through 2000. one day it threw a check engine light & i did a stomp test & got a 1213 error(o2 sensor #2). so i replaced both sensors with new o.e. sensors. no difference. it has also lost its edgy power it once had. my mechanic is suspecting clogged fuel injectors. we dumped high quality fuel injection cleaner in. i will find out soon if that will fix it but i am doubtful & frustrated. is there anything i am missing or something else i should be looking at??? i am anxious to install the e.a.t. chip i ordered over the weekend.
thanks
tim s.

1995 540i/a
1987 325e

Tim, check the rear vacuum plate and attached hoses for leaks...it's on the extreme rear of the black, plastic intake manifold. You might need a new gasket... #5 on the TIS shot.

Cheers,
Duey

[David]

I had a similar problem with rough idle. turned out to be the throttle body gasket.