ddtham

Folks,

I got off the freeway and stopped at a stoplight today and noticed the car started vibrating/shaking really badly I then put the car in Neutral and put it back to Drive again and the vibration's gone

This is the second time it happened. The first time was about a month ago at the exact same off-ramp and stoplight during the same time of the day (lunch) The difference was that the shaking was a lot worse today.

The car was fine, there was no CEL or any warning lights. Cold start was also okay and there's no vibration whatsoever when the engine was cold. There's also no misfiring, etc.

Any similar symptoms before taking it to my indie? motor mount or tranny mount perhaps? My 185 is wobbling, could this cause the crazy vibration? It felt like I was in an old Diesel truck. I checked on old threads regarding motor mount, but the symptoms sounded different. Any help would be greatly appreciated!

TemjinX2

did you upgrade your plugs? if you use mag wires, some times they come loose and cause misfiring.

Lenin

Can also be MAP sensor or TPS. See if someone with STAR can read the codes.

ddtham

Mike,

I haven't upgraded my plugs yet. I was thinking about going NGK one step colder per JTurkel's recommendation. So, I still have the original plugs and wires. Don't usually misfiring would throw CELs though? Mine was completely okay and the vibration went away right after I shifted to Neutral.

Hi Lenin,

I will check into MAP sensor and TPS, but also don't they usually throw CELs too? Nonetheless, it seems like I would have to go to my local indie seeing that I don't know anyone with STAR in the area.

On the other hand, the car has been loving the 65F weather and seems to be running better than usual as expected

TemjinX2

yeah i had a bunch of misfires on the mag wires. It will cause the car to shake until the misfire gets really bad, then it'll cause cells. I'm on oem wires and NGK copper spark plugs.

elgato

when does it act up? As you are braking, at idle, or what?

ddtham

It acted up when I was idling at a stoplight. It hasn't happened since though.

paypaboi

This exact thing is happening with my 03 C230 Kompressor except it does it pretty much every time on the first start when I am idle at stop lights. I need to know what this it is, it sounds and feels terrible and it's embarrassing when you have passengers in the car and always have to ship into neutral to stop the vibration.

JonMBZ

You got to get it hooked up to a star. I had similar issues I ended up changing my engine mounts plugs/wires and it's gone now. All are maintenance items anyways so you should probably change them all if your mileage is over 60k.

TemjinX2

stock plugs and wires should last at least 150k. I swapped out my plugs at 110k and they were still clean.

gt4awd

Doesn't sound like motor mounts to me, as I had to get mine replaced. Both were shot and had leaked out. Vibration was very bad during cold start, and stayed bad until the engine heated up substantial. Even after so still a decent amount of vibration. I would have to suggest a vacuum leak. Any other issues since? Has it repeated?

tworotorturbo

My guess would be ignition related: plugs, wires or a coil pack. I have 117K on my C32 and experienced the same thing (See my recent thread "P0300 P0350"). Sometimes it would idle rough at stop lights and it got a little better when I shifted into N (no load on engine). And it only showed these symptoms when fully warm. No MIL lights until almost 100 miles when it threw a P0300 and P0305. Changed the wires and plugs. No more problems at all.

In your case it CAN be a coil pack that acted up too. Coil packs can act up occasionally and then go back to normal.

Plugs and wires are simple to do and cheap and considered a normal wear item. Might was well change them out anyways.

ddtham

I haven't been able to duplicate the issues so far. I am planning to go one step colder NGK and OEM wires soon though. Thanks for all your help, folks!