Hello Mr. Kilmer, I have a question about my BMW. When I start up my car there's a lot of shaking and the speedometer bounces up from 1 to 0 at a constant pace. And when I drive it more the car stops doing it, it's like it shifts back to normal. Also, the model of the car is a 335xi 2008, and it has 149,000 miles. The car was bought used, and we already ran a background check. It's an automatic transmission.
to add more information, we've changed the spark plugs and the oil. I've seen it could be the throttle body. And it can't be the engine mount because they are screwed in well.
Is it shaking only when the car is stopped or also when you are driving? Have you tried to put it in neutral? Is there any difference when the engine is warmed up? Have you checked transmission mounts?
And it can't be the engine mount because they are screwed in well
Have you lifted the car by lifting the engine? Does the car lift with engine?
It shakes when it is stopped after I drive it for a while it stops shaking. I haven't checked the transmission mounts and haven't lifted it neither.
it can't be the engine mount because they are screwed in well.
Whether the engine mounts are "screwed in well" has nothing to do with whether they are any good. The rubber deteriorates over time and that car is 16 years old.
That's true, I will go ahead and change them.
That's true, I will go ahead and change them.
Jack up the motor with a floor jack, with a wood block between it and the jack. When you reach the engine, the motor mounts will want to rise with the engine, if they're still good. It they're bad, the motor will start to come free of the mount or mounts. There are usually 3 mounts, not one single mount. The weight of the engine is held by the metal of the mounts when the rubber fails, and it's kept there by gravity. The shaking is caused by the bolts, which have now become loose. Metal doesn't dampen vibrations, either, for obvious reasons.
Some Scotty's videos about motor mounts
https://www.youtube.com/watch?v=h4VqDmlR9Oc
https://www.youtube.com/watch?v=lKV2uo3tlx0