Bad Rough Idle Please Help!!

[chaison]

HI, i have a 96 ti, done about 100,000 km. It has a rough idle straight away when i start the engine in the morning, and you can hear the rear muffler going like boof boof boof, and etc. I took it to BMW and they told me that it was the cam shaft sensor. They replaced it but nothing change, still the rough idle. It seems like a misfire from the engine with the muffler going boof boof. Can anyone please help me find the solution for my problem.

And also the BMW guys told me that the rough idle comes standard with the M44 96 ti. I thought that was a load of S%#*t. Please help

[2ndBimmer]

My car, even with brand new wires and plugs, has a slightly rough idle (~600rpm).
So it seems like a bit of coarseness is normal, though nothing excessive.

[NEKO]

I changed my cam position sensor on my 97 when my car was running rough. Once the new CPS was replaced the car ran fine. I hope you can figure out what the problem is.

[ZeroG]

I changed my cam position sensor on my 97 when my car was running rough. Once the new CPS was replaced the car ran fine. I hope you can figure out what the problem is.

There are a few things that can affect idle beside that CPS. When was the last time you changed your O2 Sensor? Have you tried to trouble-shoot your ICV (Idle Control Valve)? If you model has one have you checked the status of the throttle body heater? How about your crank shaft sensor?

What exactly do you mean by a rough idle? I have a friend that thinks his idle sucks and it just fluctuates between 650 - 800 RPMS. Is the idle hunting like there is a vacume leak? Have you tried fuel injector cleaner, also try changing where you are getting your gas from maybe it's a bad tank. Have you tried running a higher octane fuel?

-Chad

[2002tii]

Hey

A simple fix and is also worth looking into is checking your fuel filter. They are under $20 at any import part place. The filter is located underneath the driver seat under the car. it is coverd by a plate that you can remove with an 8 mm socket then a clamp that is held by a 10 mm socket. followed by 2 hose clamps and away you go. this may or may not help but it is good piece of mind for the future and it is a cheap fix. it helped on my 97 I tried wires and plugs and it still was rough. The filter fixed it

[Jeff Spooner]

the 4cyl BMW's are bad about the plug wires going bad. they may ohm good but will still skip. The best way to check is when the engine is cold crank it up and measure the temp on each exhaust pipe at the head. if you dont have a temp gun spray them w/ a pump spray bottle. the skipping cyl will not burn the water off. Then replace just that wire with a known good wire. IT helps to have a few donor cars around the shop. Or switch wires between cylinders and see if it changes cylinders. if no change try swapping coils or plugs between cylinders to isolate which part is bad.