New motor/tranny mounts now stumble

[Nelsonbimmer]

I installed new motor mounts and tranny mounts and I now have a slight stumble whilst idling on my '01 540i sport. When I start it cold it more pronounced than after it's warmed but still can be felt. Also I do not see the tachometer bounce around.

I have no lights on the dash nor is the performance/acceleration affected.

The transmission shifts smoother with the new mounts.

Any ideas?'06 BMW X5 4.8is Sapphire Black/Black mfg 10/2005 58k
'01 BMW 540i Sport Jet Black/Black mfg 11/2000 90k
'00 Jeep Wrangler Sport White/Tan cloth 82k
'06 BMW Z3 Rider Green/Tan Seat (daughters push car)

[JimLev]

Did you disconnect any of the air ducts, wiring, or tubing when you replaced the mounts?

[Nelsonbimmer]

My first thought was that something got unplugged when I jacked up the engine. Which I did slowly to be sure the fan would clear the shroud and it did.

For the tranny mounts there was a cable/wire that was clipped onto the tranny bracket but I didn't unplug those.

Is the engine to body ground at the top front or toward the bottom?

Thanks,

David'06 BMW X5 4.8is Sapphire Black/Black mfg 10/2005 58k
'01 BMW 540i Sport Jet Black/Black mfg 11/2000 90k
'00 Jeep Wrangler Sport White/Tan cloth 82k
'06 BMW Z3 Rider Green/Tan Seat (daughters push car)

[Whorse]

Andreas
Queens NY
BMWCCA# 186796
86 325es (wrecked by careless driver)
87 325 300k (project for life) aka 1BADETA/Christine
00 540is 6spd 180k (daily driver)

[Whorse]

Check the plastic/rubber air boot coming from the MAF going into the TB. Mine cracked open on an old e30 when i changed the motor mounts.

Andreas
Queens NY
BMWCCA# 186796
86 325es (wrecked by careless driver)
87 325 300k (project for life) aka 1BADETA/Christine
00 540is 6spd 180k (daily driver)

[JimLev]

"Drive It Like You Stole It, A Sickness for Quickness"
The Bottle Rocket "King of Spray" 2 Stage Nitrous Oxide
Dare to be different and stand out among the crowd of me-to-cars!
No guts, no glory! Tire smoke, not traction control!
Zionsville all aluminum radiator to replace the 3 leak prone Nissens Radiators!

NOS Progressive 2 Stage Controller with port injection
Snow's Performance Methanol/Water Injection
Dinan downloads, VAC Under Drive Pulleys
Dinan Carbon Fiber CAI
Dinan Front Strut Bar
Electric Cooling Fan w/PWM controller
NGK Iridium Plugs
DDE Enhanced Angel Eyes, Smoked Lenses
Koni FSD's/H&R Springs, BAV Brass Caliper Bushings
Eisenmann Race Exhaust (from H8-Rain's car)
///M5 3.15 LSD
///M5 Sway Bars, Front & Rear
Energy Suspension Polyurethane Sway Bar Bushings
///M5 Gauge Cluster Rings ///M5 Lip Spoiler
///M5 Mirrors and Switches
Leather Z weighted shift knob (thanks H8-Rain)
Rogue “Octane” Short Shift kit w/WSR
Rogue Tranny Mounts
StopTech Brake Lines Front & Rear
Axxis Deluxe Plus pads Front & Rear
Staggered M Parallel 66, Xenons
Modified CDV, UGDO
Euro Storage Tray (thanks Zombywolf)
Redline in Diff and Tranny
Passport 8500 X50, Escort ZR3 Laser Jammer
G-Tech/Competition Pro Data Logger
Auto Enginuity OBD-II Scan Tool
25% Tint, X-Pel, LoJack
PIAA Driving Lights
35W Xenon backup bulbs
BMW CCA Member Boston Chapter

[Nelsonbimmer]

I looked over that ground cable and it looks to be in great shape. I have heard of others removing their ground cables and using some copper paste to ensure good ground.

I still have the stumble and wondering if now that I'm taking care of the cars smaller issues if it's left over and I'll have to chase it down.

Have you had experience with that?

Thanks, '06 BMW X5 4.8is Sapphire Black/Black mfg 10/2005 58k
'01 BMW 540i Sport Jet Black/Black mfg 11/2000 90k
'00 Jeep Wrangler Sport White/Tan cloth 82k
'06 BMW Z3 Rider Green/Tan Seat (daughters push car)