[JustDriveIt]

Hey guys, I've searched a little while now, but haven't found exactly what I'm experiencing.

07 335i E92 90k miles

When I first start the car (even if car is hot) when I'm in regular drive starting to drive off and when I let off the gas, I can feel the transmission "give resistance" like engine braking and I hear a metallic rattle coming from under the car, lasts about 2 seconds or so until the transmission seems to disengage and engine braking is released and it starts to coast like normal (like if you pressed the clutch in on a standard). It does not happen in neutral, not the waste gate.

Maybe the exhaust rattling? but it seems to go away after the first minute or so and I can't replicate it again.

Any ideas? Is there some kind of clutch engage in the automatic? Fluid change? I have no idea.
Thanks guys.

[dannyjones]

I have the same, especially prominent coming down parking garage ramps. I was meaning to check if it was waste gate rattle (don't really know what that sounds like). Interested in replies to this thread

[N54Twin]

Originally Posted by JustDriveIt

Hey guys, I've searched a little while now, but haven't found exactly what I'm experiencing.

07 335i E92 90k miles

When I first start the car (even if car is hot) when I'm in regular drive starting to drive off and when I let off the gas, I can feel the transmission "give resistance" like engine braking and I hear a metallic rattle coming from under the car, lasts about 2 seconds or so until the transmission seems to disengage and engine braking is released and it starts to coast like normal (like if you pressed the clutch in on a standard). It does not happen in neutral, not the waste gate.

Maybe the exhaust rattling? but it seems to go away after the first minute or so and I can't replicate it again.

Any ideas? Is there some kind of clutch engage in the automatic? Fluid change? I have no idea.
Thanks guys.

Waste gate buddy, i have the same problem.

[JustDriveIt]

Originally Posted by Kewill0360

Waste gate buddy, i have the same problem.

But why only in drive and not neutral and why only when first driving? I guess this is a recall and gets fixed for free though, right?

[N54Twin]

Originally Posted by JustDriveIt

But why only in drive and not neutral and why only when first driving? I guess this is a recall and gets fixed for free though, right?

You can go to the dealer and try to get them replace.

Vid cold start idle:https://vid.me/rhBF

Vid reving:https://vid.me/s0Jz

[motoguy128]

Originally Posted by JustDriveIt

But why only in drive and not neutral and why only when first driving? I guess this is a recall and gets fixed for free though, right?

IF I remember correctly, one function of the Wastegate/Blow-off us the prevent surging and the turbo from stalling at low loads. When coasting, there minimum pressure and the wastegate probably closes and may start rattling as the turbo starts to surge a little.

I deal a lot with centrifugal chillers, which are similar. All you need to remember is that non-positive displacement type pumps HATE low loads and changes in loads are partial pressures. They like lots of mass flow and steady state operation. That's why turbos have taken so long to get right. Its' really really hard to tune them for good drive ability, emission and flat torque curves.

[Antetokounmpo]

Warranty was 8 years/82k so you're likely SOL with a 2007.

And also: http://lmgtfy.com/?q=335i+rattle+deceleration&l=1

[JustDriveIt]

Originally Posted by Heel Toe

Warranty was 8 years/82k so you're likely SOL with a 2007.

And also: http://lmgtfy.com/?q=335i+rattle+deceleration&l=1

Thanks for the google link, except that is a car rattling when ACCELERATING, as it clearly states in the first sentence. Also that car sound's nothing like the rattle I have.

Mine is rattling when DECELERATING as in when I have my foot off the gas.

However, I'm sure it is the wastegates, I'm pretty used to BMW's shitty products and engineering at this point, and I'm 100% sure they are not going to help in any way. I have no idea why the are a successful company in the US except for people buying them solely for the "look and status".

[Reckless335]

I'm having this same problem, only I'm not making boost anymore. If I push the throttle any more than say 35% I'll go into limp mode and get the half engine light, along with the 30FF code. I use Cobb to monitor my boost and I don't make boost at all anymore. It "maxes out" at 0.0lbs of boost. If I drive it under 35% throttle, it seems to drive fine (aside from the wastegate rattle noise) but if I push it to where I'd normally build boost, instead of boost I'm getting a half engine light and limp mode.

Can I fix this by adjusting the wastegate actuator arms? Is anyone else losing boost when their wastegates rattle? I'm almost FBO (minus CP) so I'm running Cobb Stg 2+ so I normally boost around 14-16psi. Now I'm now seeing ANY.

[Antetokounmpo]

Originally Posted by JustDriveIt

Thanks for the google link, except that is a car rattling when ACCELERATING, as it clearly states in the first sentence. Also that car sound's nothing like the rattle I have.

Mine is rattling when DECELERATING as in when I have my foot off the gas.

However, I'm sure it is the wastegates, I'm pretty used to BMW's shitty products and engineering at this point, and I'm 100% sure they are not going to help in any way. I have no idea why the are a successful company in the US except for people buying them solely for the "look and status".

Oh I'm sorry, did Google only return 1 result? Or 17,000,000 like it does for me?

[n54SQUAD]

But you can test the waste gate right? By unplugging the vaccume lines to check initially?

[N54Twin]

I can still drive but i have lags, if i hit 70mph it speed up like crazy or reduce power warning pops up and if i go up a hill it feels like my car is going to stall on me.

Go to the dealer try to fight the warranty if you not over 82k or 8 years.

[JustDriveIt]

Originally Posted by Heel Toe

Oh I'm sorry, did Google only return 1 result? Or 17,000,000 like it does for me?

Man, you are so helpful, glad to have you as a part of the forum.


Anyone else with this issue have a fix that doesn't result in replacing the turbos, which would cost more than 50% of what the car is worth?

I saw a video of someone "tightening" the actuator rod, does this actually do the trick?

I'll probably end up trading it if not, don't want to have to drive my car under 35% throttle to avoid limp mode.

[N54Twin]

Originally Posted by JustDriveIt

Man, you are so helpful, glad to have you as a part of the forum.


Anyone else with this issue have a fix that doesn't result in replacing the turbos, which would cost more than 50% of what the car is worth?

I saw a video of someone "tightening" the actuator rod, does this actually do the trick?

I'll probably end up trading it if not, don't want to have to drive my car under 35% throttle to avoid limp mode.

It might, depending on the situation it could fix it but is not a permanent fix.