vibration felt throughout car when idling

[bruno6491]

Hey

i have a vibration in my car that is felt through out when the car is idling. The idle is pretty smooth and is constant at about 700 rpms. Its a 1988 325i convertible automatic and has 90k miles. Here is a list of what ive done in the last 50 miles
Its a 1988 325i convertible with an auto and 91k miles
I have done all these things within 150 miles:
Spark plugs
Spark plug/ignition wires
Distributor and cap
Rotor
Valve Cover Gasket
[COLOR=blue ! important][COLOR=blue ! important]Oil [COLOR=blue ! important]pan[/COLOR][/COLOR][/COLOR] gasket
All new radiator hoses and intake hoses, including breather hose to valve gasket and intake boot
All new filter- Fuel, Air and Oil
Oil change
OEM motor mounts
Bilstein Sports Shocks
H&R Sport springs


What would be the next thing to check to solve this vibration?

Thanks Bruno

[norcalE30]

how bad is the vibration?

[allwheeldrive]

Mine shakes. Its noticeable. I live with it cause its probably just how it is. This is before and after new motor and tranny mounts. And no its not misfiring.

[bruno6491]

its to the point where my rear view mirror shakes like if you have a system with the bass shaking it. I feel it in the seat and notice it quite a bit. Could the valves being adjusted or a new O2 senor do anything?

I dont really mind it but if im able to fix it i would like to

[abepark]

most automatics will have some vibration.

[norcalE30]

yeah mine shakes too, but not as bad as yours.... you said you replaced the motor mounts? myabe check the trans mounts...

[bruno6491]

i replaced the motor and trans mounts. I read that if the engine isnt idling 100% that it would cause vibration and one thing is maybe the O2 sensor? Also the car is a little hesitant when i get on the gas, even at low speeds so its not the tranny downshifting

[rhett325i]

Hesitation usually means vacuum leaks
Also clean your ICV with some brake cleaner
have you replaced the vacuum hose that attaches under the throttle body?
pull the vacuum hose off the FPR and give it a sniff. If you smell fuel you need a new FPR.

[acefreely02]

smelling the vac line to fpr isnt always true, or works i should say. few guys over at e30 tech had fpr problems and couldnt smell gas in the line

[bruno6491]

i will check to see all of these things. Also with the cold weather the car is sometimes hard to start, and need to pump the gas pedal. Could this be my fuel pump on the way out?

[VacMan]

Bruno, glad to see you make the jump to R3V.

What did you replace the mounts with, OEM or aftermarket? Does it shake more/less in neutral or park than in gear?

Are you sure it's firing smoothly on all 6 cylinders? The I6 is an inherently smooth motor so a misfiring cylinder isn't as easy to notice. Pull plug wires one by one while the car's running and see if there's any change. If you pull a wire and nothing changes you've found the culprit.

Make sure you trace all vacuum leaks. There are lots of writeups floating around on how to do this. Even a minor vacuum leak can cause stumbling and a loss of power.

[Jordan325iC]

My car has always done this. Even after turbocharging it and replacing pretty much everything, problem still remains. The only ignition-related things that were not replaced were the coil and plug wires.

[bruno6491]

they mounts were replaced with OEM ones. I also noticed that around 5k rpms the engine seems to lack power and die off, even tho its the top of the power band. Maybe this has something to do with it. I will check tomorrow to see if i notice it more in P,D,N,R

R3V has lots of great info and help and enjoying learning about the car

Bruno

[///M42 sport]

any updates on this? I'm having the same prob

replaced ICV, TPS, checked vacuum hoses, newer oem cat, 02 sensor, no engine codes. Still same prob.

I did notice a slight improvement after using chevron with techron injection cleaner.