[DXB12C]

I earlier posted a comment on another thread relating to an issue that I recently noticed in my car, whereby a significant vibration/shudder occurs when accelerating slightly (i.e. light throttle, just enough to kick a gear down from 5th to 6th at cruising speed) and in my case between 2000-3000 rpm when the turbo spools up.

Other members have chimed in with similar experiences, so it seems fit for this to have its own thread.

For ease, I have copied the links to the videos of this phenomenon happening in my car and in Walt's (Walt of Destiny) car. Naranja's car also appears to have similar symptoms.

My car (you can hear the sound of the dash vibrating between 2k-3k rpm):

http://youtu.be/fU4cYTwTrkA

Walt's car:

http://youtu.be/192oTa1Qavc

 

[Mrloudly]

Can't help thinking this isn't turbo related, not directly at least. If a turbo were to be out of balance enough to feel the vibration, a little buzzing would be the least of you worries ;-) Probably some sort of heat shield resonance or panel vibration. Hope you sort it ;-)

 

[Naranja]

It is 100% Turbo related, below is my original post, best I can describe it...

'Mine does this too, it's definitely Turbo related. Typically I may accelerate from low revs in auto then have to lift off almost straight away then it does it, like a low rumble that seems to make the car shudder. It's worse when hot. This should be a new thread' ... and now it is!

 

[andy c]

It is 100% Turbo related, below is my original post, best I can describe it...

'Mine does this too, it's definitely Turbo related. Typically I may accelerate from low revs in auto then have to lift off almost straight away then it does it, like a low rumble that seems to make the car shudder. It's worse when hot. This should be a new thread' ... and now it is!

I also get a vibration,but as I always have both sets of fingers on the paddle at all times
(I know its just me!!) I get the feeling through the paddle/wheel,i thought it was the gearbox vibrating,do you think it could also be this??????????

 

[Naranja]

I also get a vibration,but as I always have both sets of fingers on the paddle at all times
(I know its just me!!) I get the feeling through the paddle/wheel,i thought it was the gearbox vibrating,do you think it could also be this??????????

I'd say so Andy, I feel mine more through the seat of the pants, as it were but I'll try your method tomorrow and see... It's typically at low revs, once pressing on, past about 2.5k revs, I never feel it again.

 

[DXB12C]

Can't help thinking this isn't turbo related, not directly at least. If a turbo were to be out of balance enough to feel the vibration, a little buzzing would be the least of you worries ;-) Probably some sort of heat shield resonance or panel vibration. Hope you sort it ;-)

It definitely has something to do with the turbo in my case as it only comes about when the turbos start to spool up and then (as with Naranja's car), it disappears when you reach 3k RPM. The vibrating dash is only a symptom of the shudder/vibration of the whole car. It does a very noticeable and significant vibration, the intensity of which I can describe as similar to the kind feel throughout the car when you drive over an unpaved/gravel road.

Naranja pointed out on the other thread that in his case it intensifies when the weather is hot, ive driven it in hotter days here (last night was 33C) but never noticed this issue before yesterday (which was my first proper drive after the car came back from the dealer).

 

[Mrloudly]

The engine/exhaust is fitted in vibration reducing mountings to the chassis. Through their very nature, turbos have to be finely balanced to prevent them tearing themselves to bits. Even the slightest imbalance at 200,000 rpm would kill the bearings/seals in no time. If there were a transient vibration on spool up, I really doubt the few micro-grammes of out of balance would transmit itself through the soft mounts to the body. Balancing: http://www.youtube.com/watch?v=TMA5RFpGRbg

 

[Walt of Destiny]

I don't believe it's the turbos. It sounds like a can of rocks being shaken right in front of my feet.

The car is at the dealer as I tap this. I sent the video to them they said they'd figure it out.

In mine it's not speed dependent. I think it's a bit of the undercover loose. But I could be wrong, and I frequently am.

 

[McDc]

It is 100% Turbo related, below is my original post, best I can describe it...

'Mine does this too, it's definitely Turbo related. Typically I may accelerate from low revs in auto then have to lift off almost straight away then it does it, like a low rumble that seems to make the car shudder. It's worse when hot. This should be a new thread' ... and now it is!

Mine does it too. 100% turbo related. McLaren is looking into it. Sort of.

Thought I might be the only one.

 

[andy c]

Mine does it too. 100% turbo related. McLaren is looking into it. Sort of.

Thought I might be the only one.

Any news on what they found or didn't find on the Data logger Martin???

 

[Naranja]

Mine does it too. 100% turbo related. McLaren is looking into it. Sort of.

Thought I might be the only one.

No, you're in good company this time Martin!

 

[Mrloudly]

This is from an ex Ilmor engine builder friend of mine

"Turbos are either working fine with good balancing maintaining a hydrodynamic bearing...or completely failed with the oil bearing broken down and the whole thing failed in seconds, there isn't really an in between stage

If you can feel it, wait a few seconds and it will be scrap"

 

[garyw]

I have the occasion effect of a vibration, I thought it was a gearbox issue, usually on low revs and when asking very little of the engine power.
Never really concerned me before, it did it today on the motorway, a gear select down cured it, so not convinced it was the Turbos..

 

[McDc]

Any news on what they found or didn't find on the Data logger Martin???

Let's not open pandorra's box Andy

 

[roundincircles]

Guy's, you got me worried as my car does not do it........well I think it doesn't!

Do you have Iris or satnav on when it happens?

 

[andy c]

I have the occasion effect of a vibration, I thought it was a gearbox issue, usually on low revs and when asking very little of the engine power.
Never really concerned me before, it did it today on the motorway, a gear select down cured it, so not convinced it was the Turbos..

Well looks like we've all felt something ,but mine is under hard acceleration from low down,so im even more confused,thats why I thought it was gearbox,explains why ric has never felt it though

 

[isv]

Interesting.. and there I was wondering if I was the only one who had this as well. Slightly weird vibration in highish gear coming off the throttle on low revs... was never serious enough to really bother me though but did think it was a bit strange.

 

[Declan]

I think most 12Cs have the same vibration at 2600/2800 revs when accelerating in 3/4/5. I have experienced it in different cars and believe it is related to the clutch. Don't think it's the turbos at all

 

[Mikeyb]

Mine does it too. 100% turbo related. McLaren is looking into it. Sort of.

Thought I might be the only one.

See how many friends you have here !

 

[Owl]

I have the occasion effect of a vibration, I thought it was a gearbox issue, usually on low revs and when asking very little of the engine power.
Never really concerned me before, it did it today on the motorway, a gear select down cured it, so not convinced it was the Turbos..

I also noticed something similar a few times while driving at very low speeds in dense on -off traffic. Like Gary, it was at low revs and light pressure on gas padle, with a rather mild if not hot weather. I thought it could be the clutch overheating slightly, or even the fans' pow consumption interfering with the electrical balance of the engine. It disappeared after a few minutes, when traffic allowed Higher revs.