1999 BMW 318 Engine Vibration

Is the check engine light on? If so, what codes are present?

I had the same problem on my 318 it was dirty battery cables or loose connection, try that.

Make sure you check your ground straps from the oil pan to the frame, also check your starter connections, you have a loose connection somewhere.

Meanwhile I will sleep on it and see what comes to me in the morning

I Have been reading happen your posts, I am without sufficient information of the cars history, so let's start over again, tell me everything you have done to the car, and who has been working on it, all the parts that you have replaced, how long you had the car, When did the problem occur and what you did to correct it, has the vehicle been sitting for a long period of time ect.

Here are a list of diagnostic procedures, if you need to know how to do them let me know, I will step you through them.

ENGINE RUNS ROUGH (OFF IDLE)
Fouled spark plugs.
Burned or sticking valve.
Ignition system malfunction.
Intake manifold air leak.
Fuel injector not operating.
DME/Motronic control unit malfunction.
Blown head gasket.

ROUGH OR UNSTABLE IDLE
Fouled spark plugs.
Burned or sticking valves.
Intake manifold air leak.
Incorrect valve timing.
Ignition system malfunction.
Fuel injector not operating.
DME/Motronic control unit malfunction.
Blown head gasket.

LOSS OF POWER
Insufficient fuel pressure.
Restricted fuel filter.
Restricted air filter.
Ensure engine compression is okay.
Ignition system malfunction.
Burned or sticking valves.
Restricted exhaust system.
DME/Motronic control unit malfunction.
Incorrect valve timing.

http://www.realoem.com/bmw/showparts.do?model=AL31&mospid=47631&btnr=11_1514&hg=11&fg=15

Inspect the crankcase vent valve, replacement of the valve is typically the solution to your dilemma. It is #1

Sorry I have been a little busy and unable to get back to you. I will now step you through the diagnostic procedure:

ROUGH OR UNSTABLE IDLE

1. Fouled spark plugs: remove all of the spark plugs and check them for contamination, gas or oil residue, make sure the spark plugs are cleaned and properly gap before reinstalling.

2. Burned or sticking valves: this procedure is a little bit more difficult so we will bypass it for now.

3. Intake manifold air leak: get yourself a little propane torch like the plumbers use, with the engine running take the torch do not light it! Just turn on the gas and check all are found the intake, injectors, all vacuum lines and the intake duck, if the engines smooth out you found your vacuum leak, if there is a vacuum leak.

4. Incorrect valve timing: this may be an issue due to the fact that you stated "The problem comes 7-8 months ago and increase gradually" when was the timing belt last changed? As the timing belt gets old it stretches and changes the valve timing, remove the timing belt cover and inspect the belt.

5. Ignition system malfunction: the engine on TDC remove the distributor cap makes sure of the rotor and the cap are in good condition, also make sure the rotor is pointing to cylinder number one, inspect the spark plug wires make sure they are in good condition, and when you put them back on the spark plugs make sure they click on every spark plug.

6. Fuel injector not operating: take a small piece of hoses, long enough to reach the injectors and your ear, so you can listen to see the injectors are operating, the injectors will make a distinct clicking sound make sure they sound all the same, if you have one injector that is making a different clicking sound that is your problem, you can try some injector cleaner to resolve the problem or replace the injector.

7. DME/Motronic control unit malfunction: the only way to determine if the computer is not functioning properly it is usually intermittent, it will work until it gets hot and then it will shut down a certain function, ignition, timing advance, injectors, ect.

8. Blown head gasket: if the vehicle has the blown head gasket you will have a dead cylinder, you can determine this by a compression check, also examine the spark plugs if it has the blown head gasket sparkplug will usually be very clean, or it will have white particles of coolant stuck to the spark plug.

If you need any more help or have further questions do not hesitate to respond.

And dont forget to do what Dr. Hagerty said "Inspect the crankcase vent valve, replacement of the valve is typically the solution to your dilemma. It is #1"

http://www.realoem.com/bmw/showparts.do?model=AL31&mospid=47631&btnr=11_1514&hg=11&fg=15