Vibrations at certain RPM

[Ripnz]

I’m not an engineer or a mechanic, so did some ‘research’ on Google and watched a few YouTube videos. I think in my case I can rule out the drive shafts as the vibration occurs at 1800 rpm which equates to different driveshaft rpm depending on gear and speed. I’m also thinking the heat shield rattle is a result of the base resonance, so bending it out of the way may reduce the noise and some vibration but is masking the true cause.
I’m leaning towards engine/transmission mounts as it only occurs under power. Could also be a torque converter issue.

 

[Hannes01]

Thank you! Just wrote an email to Mr Anselment. Tomorrow I have to go to Hanau perhaps I drop in at K&E on my way home

Maybe have a look for a Fieldmaster in MM, 17 Alloys and winch!

 

[Clark Kent]

Mentioning it for the sake of inclusion: exhaust drone, rumble, pressure waves?
This vehicle has a large bore stainless exhaust and high volume chambers in the cat, DPF and rear muffler.

Also agree this vibration seems rpm specific not road speed related. Standard engine mounts used with the B57 in BMW vehicles are fluid damped as far as I can ascertain. We have substantial solid rubber mounts.

I did a test in manual mode yesterday and held the engine in the 1800 - 2000rpm range in 3rd gear. I could produce that vibration by varying the rpm, albeit at a low amplitude. Throw in the potential for sympathetic vibrations in the many heat shields (low mass, high moment), if harmonics are being transmitted through the solid engine mounts, and we could be looking at a complex system of vibrations from a single engine-based source.

Just a working theory. Akin to running your wet finger around the top of a crystal wine glass. Get the speed (frequency, rpm) right and it will sing!

 

[DaBull]

I’m not an engineer or a mechanic, so did some ‘research’ on Google and watched a few YouTube videos. I think in my case I can rule out the drive shafts as the vibration occurs at 1800 rpm which equates to different driveshaft rpm depending on gear and speed. I’m also thinking the heat shield rattle is a result of the base resonance, so bending it out of the way may reduce the noise and some vibration but is masking the true cause.
I’m leaning towards engine/transmission mounts as it only occurs under power. Could also be a torque converter issue.

Hi Ripnz, I started this original post thread. Perhaps it bears reading again as a possible cause or cure. Not sure, however worth more consideration now that Grenadier is talking about engine and transmission mounts being too tight, when all Ineos Grenadier may need to do is install a damper to negate and absorb all the vibrations. Perhaps someone should get this to Ineos so they could see if this might help or cure the main vibration issues. It completed cured a very similar if not identical vibration on my Range Rover Sport.

Vibrations at certain RPM

In regards to the vibrations many seem to be feeling on their new Grenadiers, it reminded me of having the same thing happen on a couple of my Range Rover Sports, where I was feeling a vibration at certain rpm’s through my steering wheel. One was related to the tires/rims needing much better...

www.theineosforum.com

 

[emax]

this vibration seems rpm specific not road speed related.

I think there is general agreement on this.

 

[Wayneos]

....Standard engine mounts used with the B57 in BMW vehicles are fluid damped as far as I can ascertain. We have substantial solid rubber mounts.

I updated the engine mounts in my E46 M3 from stock to slightly harder rubber, at idle it vibrates a lot more whereas before it was smooth but it's fine at all higher revs. I'm putting my money on engine mounts and/or tranny mounts being the cause of this vibration in the Gren.

 

[DaBull]

I updated the engine mounts in my E46 M3 from stock to slightly harder rubber, at idle it vibrates a lot more whereas before it was smooth but it's fine at all higher revs. I'm putting my money on engine mounts and/or tranny mounts being the cause of this vibration in the Gren.

Hi Wayneos, I think we are talking about the same thing. There is obviously something in the drive train setting up a resonance that is causing vibration at certain rpms.
Softer torque settings on the engine and transmission mounts sounds like how Ineos is trying to address the vibration and absorb some of it. My point is that having a vibration damper installed, like what was done by Land Rover on my Range Rover Sport, may work and also may have the added advantage of not only damping the vibration but also completely cancelling out the vibration. When you experience how smooth a drive train can be and then have the vibration show up at certain rpm's, I found it just plain pissed me off until I kept digging to find out the cause and had it fixed. It was pure bliss afterwards. DaBull

 

[klarie]

@emax update from K&E my car has arrived. Later this morning I visit and take some pictures. More to come.

 

[PBD]

Hi all,
DCPU suggested a cure for the hi pitched rattle in June on this thread.
I did bend the heat shield he indicated and it solved 90% of the rattle, good news.
Bad news is that the engineers worked to solve this issue whilst they had my truck for a month. The heat shield is in one big piece all down the off side of the engine, the stripped the airbox out etc and bent it into a new shape. Unfortunately the rattle is now back up to 100%

 

[James]

I updated the engine mounts in my E46 M3 from stock to slightly harder rubber, at idle it vibrates a lot more whereas before it was smooth but it's fine at all higher revs. I'm putting my money on engine mounts and/or tranny mounts being the cause of this vibration in the Gren.

The logic is looking quite strong. Couple of ‘gut’ thoughts-
does anyone else wonder why the diesel and petrol versions of a straight 6 (most balanced engine type) would exhibit a difference here? It doesnt feel impossible, but it does feel unlikely that only one would have an rpm related unwanted resonance. Maybe the mounts are different…
second, the gearboxes are different. Not a lot, but they are different units.

 

[trobex]

Nothing a visit to Clark rubber and a tube of Sika can't fix!!!

 

[grenadierboy]

Hi Wayneos, I think we are talking about the same thing. There is obviously something in the drive train setting up a resonance that is causing vibration at certain rpms.
Softer torque settings on the engine and transmission mounts sounds like how Ineos is trying to address the vibration and absorb some of it. My point is that having a vibration damper installed, like what was done by Land Rover on my Range Rover Sport, may work and also may have the added advantage of not only damping the vibration but also completely cancelling out the vibration. When you experience how smooth a drive train can be and then have the vibration show up at certain rpm's, I found it just plain pissed me off until I kept digging to find out the cause and had it fixed. It was pure bliss afterwards. DaBull

As I mentioned - when I got "the man" (head service technican at the closet INEOS agent to me but not mine) to rev the (diesel) engine, then place it in Drive with foot on brake & feel the vibrating steering wheel and then put his hand on engine cover - he said........"probably an engine mount issue - get your agent to check it out up once it's up on the hoist"........

 

[AWo]

The logic is looking quite strong. Couple of ‘gut’ thoughts-
does anyone else wonder why the diesel and petrol versions of a straight 6 (most balanced engine type) would exhibit a difference here? It doesnt feel impossible, but it does feel unlikely that only one would have an rpm related unwanted resonance. Maybe the mounts are different…
second, the gearboxes are different. Not a lot, but they are different units.

There are differences in the behaviour of Diesel and Petrol engines, even if they are natually balanced straight 6 in regards of vibrations. And as far as I understand it is an issue not related to the engine rpm but the speed of the car. That rules all engine related stuff out. Did I mention to check the balance of the drive shaft...?

AWo

 

[emax]

There may be two kinds of vibrations: a) related to the engine RPMs, and b) related to the drive shafts RPM (i.e. car velocity).

I personally have so far only experienced engine related vibrations. But this might be different for others.

typo​

 

[NQ94]

The logic is looking quite strong. Couple of ‘gut’ thoughts-
does anyone else wonder why the diesel and petrol versions of a straight 6 (most balanced engine type) would exhibit a difference here? It doesnt feel impossible, but it does feel unlikely that only one would have an rpm related unwanted resonance. Maybe the mounts are different…
second, the gearboxes are different. Not a lot, but they are different units.

The difference between the diesel and the petrol would be the cylinder pressure during combustion and the engine speed to produce the maximum torque. Petrol and diesel ignition processes are very different when seen with high speed photography. The tendency now is for vehicle manufacturers to have the vehicle at near peak torque in the highest gear at the lowest engine rpm for normal road speeds. This is known to cause extra resonance and vibration through the drive drive line. Clutch and transmission manufacturers try to alleviate the low engine speed vibrations by adding extra or different dampeners to torque converters and clutches and changing shift strategies in transmissions.
Vehicle manufacturers add rubber mounted weights to the exhaust, transmission and chassis to try and absorb some of the vehicles harmonics.
Ineos also uses CV joints in its drive shafts to try and eliminate the phase speed differences causing vibrations from universal joints operating close to maximum working angles.
Vibration and resonance through a vehicle can be difficult to diagnose and isolate.

 

[DaBull]

The difference between the diesel and the petrol would be the cylinder pressure during combustion and the engine speed to produce the maximum torque. Petrol and diesel ignition processes are very different when seen with high speed photography. The tendency now is for vehicle manufacturers to have the vehicle at near peak torque in the highest gear at the lowest engine rpm for normal road speeds. This is known to cause extra resonance and vibration through the drive drive line. Clutch and transmission manufacturers try to alleviate the low engine speed vibrations by adding extra or different dampeners to torque converters and clutches and changing shift strategies in transmissions.
Vehicle manufacturers add rubber mounted weights to the exhaust, transmission and chassis to try and absorb some of the vehicles harmonics.
Ineos also uses CV joints in its drive shafts to try and eliminate the phase speed differences causing vibrations from universal joints operating close to maximum working angles.
Vibration and resonance through a vehicle can be difficult to diagnose and isolate.

Hi NQ94, Thanks for the detailed explanation of causes of resonance and vibration. Explains why they added a donut damper to my Range Rover Sport, which in my case completely eliminated the vibration. Hopefully Ineos comes up with a solution that is as simple. DaBull

 

[grenadierboy]

The difference between the diesel and the petrol would be the cylinder pressure during combustion and the engine speed to produce the maximum torque. Petrol and diesel ignition processes are very different when seen with high speed photography. The tendency now is for vehicle manufacturers to have the vehicle at near peak torque in the highest gear at the lowest engine rpm for normal road speeds. This is known to cause extra resonance and vibration through the drive drive line. Clutch and transmission manufacturers try to alleviate the low engine speed vibrations by adding extra or different dampeners to torque converters and clutches and changing shift strategies in transmissions.
Vehicle manufacturers add rubber mounted weights to the exhaust, transmission and chassis to try and absorb some of the vehicles harmonics.
Ineos also uses CV joints in its drive shafts to try and eliminate the phase speed differences causing vibrations from universal joints operating close to maximum working angles.
Vibration and resonance through a vehicle can be difficult to diagnose and isolate.

Many Thanks for your great overview - it makes sense

I have printed this and will take it with me when I go to my agent in the next few weeks.

 

[Maxwell]

Hi guys, I have had my Grenadier Trialmaster (Diesel, LHD) delivered a few weeks ago. The car had been sitting a the dealer for about 9 months. After a few kilometres driven, the yellow engine light came on. That issue came from a loose lambda probe also causing exhaust fumes to leak into the passenger cabin. However, I now have the car back from the workshop and I also still experience these vibrations of the engine and drivetrain at certain rpms and speeds.

Can anyone who has had the same issue (vibrations) tell me how the issue can be fixed or was fixed, respectively? The vibrations really ruin my Grenadier fun.

 

[AWo]

Balance the prop-shaft....

AWo

 

[YellowLab]

Hi Fidei, I found the mention of vibrations from owners who had taken possession of their vehicles and were reporting their findings under the thread
"So Where Are All Your First Impressions". Check out the following posts under that tread;
Post 215 by Wiaspria
Post 217 by MrJar
Post 229 by grenadier boy.
The vibration issue not stopping me from converting from a reservation holder to placing an order in May in the US. Just would be nice to determine what may be causing it as from previous ownership experience of my Range Rover Sports, it annoyed me on a new vehicle purchase and luckily I found what caused it and got it resolved. Hoping this forum for Grenadiers also finds the cause and the fix for those that might have the issue. Respectfully, Da Bull

Think it happened more in the diesel versions than petrol correct?