Vehicle Shaking 50i

[buckeyewalt]

This has happened to me several times and I really don't think it's an issue, just want to see if any other guys have the same thing.

When traveling at any speed when the vehicle shifts into the last gear (8th), does anybody else experience a shake in the engine when the accelerator is barely depressed. I think I know what the issue is, it's because it's in final gear and it's stumbling a little. Just like a manual transmission where you are going to slow in final gear.

When I give it gas, it goes no problem. Probably dropping into last hear a little too early I expect.

[MattBianco]

Here is a way to test your deduction: Drive in Sport, or Sport+ if you have it. It should upshift to 8th from 7th at a higher RPM. Or, it's your music (joke ends)

[buckeyewalt]

Confirmed, doesn't do it in sport. Just wondering if anyone else noticed on their vehicle,

[ingenieur]

RPM's are low right? Sounds normal.

[retx]

Originally Posted by ingenieur

RPM's are low right? Sounds normal.

Resonance? due to the low RPM in the OD gear?


One of my old cars used to have this problem and the dealer had to add the additional buffer to absorb the vibration.

[cenix]

I don't have the 50i but it sounds like perhaps the engine is lugging a little bit as you mentioned? In other words, the RPM's are too low for the speed. Have you determined this to be a transmission issue or normal operation?

[originalgoods13]

I had the same exact experience after a drivetrain malfunction and whenever I depress the gas pedal it rumbles

I am surprised your vehicle is not throwing a code "drivetrain malfunction"

[42pilot]

Originally Posted by originalgoods13

I had the same exact experience after a drivetrain malfunction and whenever I depress the gas pedal it rumbles

I am surprised your vehicle is not throwing a code "drivetrain malfunction"

I agree. That is why the car has a torque converter and electronic shifting. There should be zero shuttering or the sounds of the engine lugging. The torque converter should be taking up the low-end rpm and converting it to transmission rotation fully around 1500 rpm or so. In addition, the clutches in the transmission should be making shifting butter smooth - from any speed or any RPM.

[buckeyewalt]

Originally Posted by 42pilot

I agree. That is why the car has a torque converter and electronic shifting. There should be zero shuttering or the sounds of the engine lugging. The torque converter should be taking up the low-end rpm and converting it to transmission rotation fully around 1500 rpm or so. In addition, the clutches in the transmission should be making shifting butter smooth - from any speed or any RPM.

I have no issue with it shifting, down or up shifting, just when it gets around 1100-1300 in 8th gear traveling around 40 mph that when I notice some shuttering and if I didn't give it gas it would shutter quite a bit.

[buckeyewalt]

Originally Posted by originalgoods13

I had the same exact experience after a drivetrain malfunction and whenever I depress the gas pedal it rumbles

I am surprised your vehicle is not throwing a code "drivetrain malfunction"

GEEEZ don't say that....

[42pilot]

Originally Posted by buckeyewalt

I have no issue with it shifting, down or up shifting, just when it gets around 1100-1300 in 8th gear traveling around 40 mph that when I notice some shuttering and if I didn't give it gas it would shutter quite a bit.

Yikes - I still think it's an issue for the dealer to investigate...

[mikikuki7]

I know echar you are talking about. Like ejem you remove the foot from the gas pedal it does it too. Like a vibration. As if the injectors needed cleaning to something. I noticed also that when you accelerate just a bit it doesn't have enough power and the engine shakes. Just like an old car.

[buckeyewalt]

Originally Posted by mikikuki7

I know echar you are talking about. Like ejem you remove the foot from the gas pedal it does it too. Like a vibration. As if the injectors needed cleaning to something. I noticed also that when you accelerate just a bit it doesn't have enough power and the engine shakes. Just like an old car.

Yep, that's it!

[mikikuki7]

Originally Posted by buckeyewalt

Yep, that's it!

Sorry for all the misspellings lol, I had me keyboard set on Spanish lol. Anyway, yes, I'm going to take it for service and I'll have them check out the injectors, it happened on my X6. They actually changed the injectors on that one. Let's see what they say about this one! Once a new vehicle hits the 15k miles, that's when I notice the engine shaking...

[buckeyewalt]

Originally Posted by mikikuki7

Sorry for all the misspellings lol, I had me keyboard set on Spanish lol. Anyway, yes, I'm going to take it for service and I'll have them check out the injectors, it happened on my X6. They actually changed the injectors on that one. Let's see what they say about this one! Once a new vehicle hits the 15k miles, that's when I notice the engine shaking...

I have a little over 7200 miles and really it did it around the 1000 mile mark. It only does it when it's in 8th gear around 40mph with it slightly off throttle. Seems really weird to me that it would be the injectors, I just attributed it to of throttle shudder.

[AresM3]

I am having the same exact problem. Mine is around 40-45 mph if I am either staying at that speed (maybe a slight let off of the gas) or if I am just accelerating slowly (due to traffic of course). From what I can tell, it is not getting any worse. I am going to have them check it out next time I get the oil changed. Please let us know what you all find out.

[aroach04]

Anybody ever get a final decision on what was causing this? I think my 50i just started doing this recently.

[alphaod]

I think the problem is you guys aren't flooring it. When you're trying to go top speed, the car never shifts to 8th gear.

Sorry I'm not much help, but I'll see if my car does it. How many miles you guys have?

[bimmermann881]

Originally Posted by aroach04

Anybody ever get a final decision on what was causing this? I think my 50i just started doing this recently.

I have a x3 35i that had been "jumping and jutting" at low speeds for a while (I told them in the past it has been always doing this) than I had a drive train malfunction and it would not move or start so when it got towed in they said the valetronic motor went and now it better but I think it still doing it but it's not as noticeable or often!