A few questions about S54 engine

[SaltyNC]

Guys, can you tell me if the throttle body shaft on your S54 engine has some play in it? It's #13 in the diagram, below. I can move mine back and forth lengthwise and make it rattle. I've also attached a photo.

http://www.realoem.com/bmw/enUS/show...diagId=13_0911


When you're out of gear and increasing the throttle from idle, do you get any points where you feel some vibration come through the car as the RPM's rise?

Finally, I found some older posts where others have experiencesd this, but I never found a definitive answer. After the car has set overnight, when the engine is first started, there is a clattering sound that lasts for a second or so. It occurs with the clutch in or out. I think one theory was the chain slapping the housing of the oil pump. I thought it might be related to the vanos, but since having all of the vanos work done and the chain guide replaced, I still hear that clattery sound when I crank the motor first thing in the morning. Do you guys have that? Do we know what it is? Any way to prevent it?

Thanks!

Salty

[StickMon]

I can verify the play in the throttle rail.
When I had a recent go-around with throttle positions sensors I spent a while mucking with it.
Given the way it functions, end-to-end play has no bearing on it. Round-and-round is the important movement.

"do you get any points where you feel some vibration come through the car as the RPM's rise?"

HA!
I have Bimmerworld motor mounts. There's a spot around 1800 rpm where I don't feel much vibration.
The rest of the range is a variable frequency butt massage.
Dash rattles? You betcha! Different ones hit resonances at different RPMs.
Cup holder at 1200 rpm, ash tray at 2400 rpm, ...
It's a symphony.

Can't say I hear anything unusual when I first crank it, but maybe I just haven't noticed.
Wouldn't be surprised at some noise before the oil gets distributed.

[SaltyNC]

Originally Posted by StickMon

I can verify the play in the throttle rail.

Thanks for sharing your experience, Stickmon. Good to know the throttle rail play is normal.

That's funny about the vibration symphony. I have the Vibratechnics that you used to have before it split on you. I don't really get any rattles, but when I'm sitting in neutral and I increase the RPM, I feel something like an engine shudder...almost like the engine isn't balanced quite perfectly.I'm going to check my bolts again to make sure they haven't worked loose.

You know the dual mass rattle we get if we don't push in the clutch when turning off the engine. It sounds similar to that, but a lot faster. It's a 1 sec or less clattering sound, then it's gone and won't return until the next day. I'm overly sensitive to noises, now. Once I get the bearings swapped, I'll be able to settle down.

Thanks again.

Salty