CDTi Tourer Roof Vibration 1700 to 1800 rpm

Djangoz · 9th January 2017, 11:03

I've read a few threads describing vibration occurring between about 1700 to 1800 rpm affecting diesel tourers only, which sounds like it's coming from the engine area but is in fact coming from the roof panel vibrating against the lateral reinforcing panels between the headliner and the roof itself.

I do have this vibration issue and I've convinced myself that that is what I've got by pressing on the headliner above my head whilst driving at those revs and managing to stop the vibration.

So I was all fired up to tackle the issue by dropping one side of the headliner and running a bead of silicone sealer between the roof and the reinforcing panels as others have described.

However, one of the threads (which I can't for the moment track down) reported that about a year after doing this, one owner claimed he could actually see a dent across the roof corresponding to the line of silicone he had applied the year before. As if the space being filled (even by a flexible filler like silicone) was sufficient to transmit the vibration which was still "trying" to occur through to the roof panel to the extent that it was deforming the roof itself.

This has made me a bit nervous to try the silicone sealant method and I wonder if anyone has tried using Dynamat or similar applied to the inside of the roof panels in an attempt to damp out the resonant frequencies responsible?

I'm not sure whether the Dynamat adhesive would be reliable under the full heat of the sun - although the same would apply with silicone sealant I suppose (or "No More Nails" as one owner has apparently used).

Would welcome any views on the subject especially if you've solved the problem on your own car.

COLVERT · 9th January 2017, 12:33

As you say--" a resonant frequency"

It is probably being generated by being in Sympathy with another source.

The vibration is quite likely starting at the engine.

At the revs you mention the roof starts to vibrate at it's own Resonant Frequency which matches that of the engine.

Check the engine mounts. Maybe even move them a fraction.

You need to find the source of the problem and not just look at the results.-

grivas · 9th January 2017, 14:14

Quote:

Originally Posted by Djangoz

I've read a few threads describing vibration occurring between about 1700 to 1800 rpm affecting diesel tourers only, which sounds like it's coming from the engine area but is in fact coming from the roof panel vibrating against the lateral reinforcing panels between the headliner and the roof itself.

I do have this vibration issue and I've convinced myself that that is what I've got by pressing on the headliner above my head whilst driving at those revs and managing to stop the vibration.

So I was all fired up to tackle the issue by dropping one side of the headliner and running a bead of silicone sealer between the roof and the reinforcing panels as others have described.

However, one of the threads (which I can't for the moment track down) reported that about a year after doing this, one owner claimed he could actually see a dent across the roof corresponding to the line of silicone he had applied the year before. As if the space being filled (even by a flexible filler like silicone) was sufficient to transmit the vibration which was still "trying" to occur through to the roof panel to the extent that it was deforming the roof itself.

This has made me a bit nervous to try the silicone sealant method and I wonder if anyone has tried using Dynamat or similar applied to the inside of the roof panels in an attempt to damp out the resonant frequencies responsible?

I'm not sure whether the Dynamat adhesive would be reliable under the full heat of the sun - although the same would apply with silicone sealant I suppose (or "No More Nails" as one owner has apparently used).

Would welcome any views on the subject especially if you've solved the problem on your own car.

Just use a few pieces of cushion foam carefully placed, job done.

Number 6 · 9th January 2017, 15:34

I have used the "Silicone " method and this was several years ago.Living in France we have extremes of hot and cold and I have never had a problem with any deformation of the roof on my tourer

trikey · 9th January 2017, 15:36

Quote:

Originally Posted by Number 6

I have used the "Silicone " method and this was several years ago.Living in France we have extremes of hot and cold and I have never had a problem with any deformation of the roof on my tourer

This method and a few strips of duct tape along the pressed steel edge of the roof support works well.

Djangoz · 9th January 2017, 22:20

Quote:

Originally Posted by COLVERT

As you say--" a resonant frequency"

It is probably being generated by being in Sympathy with another source.

The vibration is quite likely starting at the engine.

At the revs you mention the roof starts to vibrate at it's own Resonant Frequency which matches that of the engine.

Check the engine mounts. Maybe even move them a fraction.

You need to find the source of the problem and not just look at the results.-

Good advice but from trawling the archives it seems that few if any folks have solved this particular issue by attention to engine mounts. Indeed several have gone to the expense of replacing mounts only to find the problem remains. Maybe just an unfortunate issue with the tourer setting up an annoying resonant vibe due to a combination of factors. I don't feel my engine vibrates unduly even at idle so think I'll go with tackling the vibration at the "active" site!

Djangoz · 9th January 2017, 22:24

Quote:

Originally Posted by Number 6

I have used the "Silicone " method and this was several years ago.Living in France we have extremes of hot and cold and I have never had a problem with any deformation of the roof on my tourer

Good to hear your experience in this case - I must admit I thought it was strange to hear of distortion occurring with soft silicone. Did you use any particular brand? Maybe the other guy used something semi setting like an acrylic mastic or something.

Djangoz · 9th January 2017, 22:28

Quote:

Originally Posted by trikey

This method and a few strips of duct tape along the pressed steel edge of the roof support works well.

Thanks for that - will see how it looks when I've dropped one side of the headlining. Only want to do the job once!

Arctic · 9th January 2017, 23:29

kitchen pad scourer ten in a pack for 50p, drop head lining a little and add two or three each side with the scourer facing down sponge touching the steel roof job done.

You can poke them in with a cane or long screwdriver Arctic

2.8jonmy · 10th January 2017, 16:03

A new lower engine mount fixed my 1800rpm roof vibration.
Jon.

9th January 2017, 11:03	#1
Djangoz Regular poster Rover 75 Tourer Join Date: Nov 2016 Location: Plymouth Posts: 37 Thanks: 4 Thanked 6 Times in 3 Posts	CDTi Tourer Roof Vibration 1700 to 1800 rpm I've read a few threads describing vibration occurring between about 1700 to 1800 rpm affecting diesel tourers only, which sounds like it's coming from the engine area but is in fact coming from the roof panel vibrating against the lateral reinforcing panels between the headliner and the roof itself. I do have this vibration issue and I've convinced myself that that is what I've got by pressing on the headliner above my head whilst driving at those revs and managing to stop the vibration. So I was all fired up to tackle the issue by dropping one side of the headliner and running a bead of silicone sealer between the roof and the reinforcing panels as others have described. However, one of the threads (which I can't for the moment track down) reported that about a year after doing this, one owner claimed he could actually see a dent across the roof corresponding to the line of silicone he had applied the year before. As if the space being filled (even by a flexible filler like silicone) was sufficient to transmit the vibration which was still "trying" to occur through to the roof panel to the extent that it was deforming the roof itself. This has made me a bit nervous to try the silicone sealant method and I wonder if anyone has tried using Dynamat or similar applied to the inside of the roof panels in an attempt to damp out the resonant frequencies responsible? I'm not sure whether the Dynamat adhesive would be reliable under the full heat of the sun - although the same would apply with silicone sealant I suppose (or "No More Nails" as one owner has apparently used). Would welcome any views on the subject especially if you've solved the problem on your own car.

9th January 2017, 15:34	#4
Number 6 This is my second home Rover 75 tourer Club CD/Limo Tints Join Date: Nov 2008 Location: Meneac Posts: 6,759 Thanks: 5,007 Thanked 1,609 Times in 869 Posts	I have used the "Silicone " method and this was several years ago.Living in France we have extremes of hot and cold and I have never had a problem with any deformation of the roof on my tourer __________________ ] "I started out with nothing, and Ive still got most of it left!"

9th January 2017, 12:33	#2
COLVERT This is my second home R75 Saloon. Join Date: Feb 2009 Location: France/or Devon. Posts: 14,003 Thanks: 3,851 Thanked 2,167 Times in 1,816 Posts	As you say--" a resonant frequency" It is probably being generated by being in Sympathy with another source. The vibration is quite likely starting at the engine. At the revs you mention the roof starts to vibrate at it's own Resonant Frequency which matches that of the engine. Check the engine mounts. Maybe even move them a fraction. You need to find the source of the problem and not just look at the results.-

10th January 2017, 16:03	#10
2.8jonmy Regular poster Rover 75 tourer Join Date: Aug 2016 Location: Redruth Posts: 79 Thanks: 18 Thanked 12 Times in 7 Posts	A new lower engine mount fixed my 1800rpm roof vibration. Jon.