Sound deadening

[colinthefox]

Have you checked that your air induction path is completely good and sealed all the way up to the air scoop inside the left hand intake grille. I'm sorry to bang on about this (I may have mentioned it before!), but induction noise can make an enormous difference to sound levels inside the van. Looking at some of the photos on here, it seems that when alternative engines are fitted, the induction tract is often overlooked, especially the flexible between the downpipe and the engine.

[Ian and Lins]

Just had a 'back to metal' restoration of our van (and dead pleased with it) but on driving it was a lot noisier than before. It turns out that a lot or all of the 'cardboard' baffles in the front/radiator bit were disposed of. This has resulted in a lot more noise. I need to look at an original van to replicate these panels, but it could be a cause of your road noise?

[JamesT25]

can anyone shed any light on these elusive cardboard baffles? I also had a respray and would like to try anything to get rid of some wind noise when the van is "flying" along!

if anyone can tell me where, what size and how many that would be brilliant

Thanks

James

[anaconda]

Have you checked that your air induction path is completely good and sealed all the way up to the air scoop inside the left hand intake grille. I'm sorry to bang on about this (I may have mentioned it before!), but induction noise can make an enormous difference to sound levels inside the van. Looking at some of the photos on here, it seems that when alternative engines are fitted, the induction tract is often overlooked, especially the flexible between the downpipe and the engine.

I havnt Colin. At this stage as suggested above im set on buying some flashband and will look to apply to all body panels/surfaces other than those adjacent to the engine itself. Ive been googling and it appears there are some decent results, also again as mentioned above the silver bubble wrap may be an option. You tube has given some good examples.

To be clear - I have an air filter situated in the cavity to the left just above the engine with ducting tube down to the engine. Are you saying the ducting should be insulated in some way, or is this something to do with the intake/ducting contacting metal parts? Please excuse my ignorance , im a novice. I was actually thinking of applying flashband to the walls surrounding the airfilter as they are currently bare metal.

[anaconda]

Cover as much as possible. Strategically placed is mostly about a weight & £££ compromise. Use as much as possible. The rear engine hump is a good area to deaden. Ideally, from outside with the mass (flash banding/bitumatic stickums), heavy underlay or carpet on the inside. Ditto the whole engine cover and rear floor.

Good bonding helps, the laminate (e.g. flash banding)does need to be bonded well over its whole area ideally. Degrease first and can use a small hard roller to press onto surface easily.

The suggestion that the engine mounts might contribute was a good one... is it a std. diesel conversion using the VW bellhousing and mounting bars?

Is the noise predominantly the normal diesel 'rattle' (knock/mechanical noise) or exhaust or inlet suction noise ?

Does it feel mainly acoustically transmitted (air-borne) or mechanically transmitted (through the body) ?

Other than the Wiki here, there's been recent discussion on the Brickyard about soundproofing (somewhere amongst its many and varied forums)

Thanks for that. Difficult to say re the type of noise but its fairly low frequency. It really just sounds like the engine is all around me.

Its a turbo diesel. I wouldnt know where to start re bellhousing and mounting bars. I'll take advice perhaps at the next local meet.

[anaconda]

Literally just finished fitting some flash-banding as recommended on here as opposed to using Dynamat. I'm not sure as I should be covering as much inner surface as possible or just strategically placed. Reason for the doubt is there are several videos on youtube showing both techniques. Which would produce the best results? Rob

So how did it go Rob...any difference?

[fotherespie]

We have a rather disturbing whistling sound that is deafing in the cab, I have a feeling it may be coming from one of the seels. Does anyone have any idea what it maybe or how we can track it down?

[HarryMann]

Whistling sound, possibly between door (hinge-line) and body ? The Caravelles I think had a stiffened rubber insert insidde the door hinge cavity. But I could easily be wrong on that, keep asking someone will know

also again as mentioned above the silver bubble wrap may be an option

IMHO... waste of time unless its just stopping up an air gap. Good heat insulation but will only stop medium/high freq. low amplitude sound.

[Si_P]

Whistling sound, possibly between door (hinge-line) and body ? The Caravelles I think had a stiffened rubber insert insidde the door hinge cavity. But I could easily be wrong on that, keep asking someone will know

also again as mentioned above the silver bubble wrap may be an option

IMHO... waste of time unless its just stopping up an air gap. Good heat insulation but will only stop medium/high freq. low amplitude sound.

I think you're being generous assuming the bubble wrap will touch medium and high frequencies. If its not stopping wholes it will add an insignificant amount of mass to the system. To give a comparison if you're improving the sound insulation of a studwork wall you would look to double the mass of the system (i.e. same amount of plasterboard again) to get a sensible improvement.

[CovKid]

ALDI selling giant playmat stuff as part of their camping stuff today. Would make great sound deadening above engine lid at least. Seems very light - go check it out. Think its available in blue or green - you get a LOT for £10 too....

[Plasticman]

That mat stuff is good but i think only for thermal losses/gains as I reckon its density is too low to effect the noise if that makes sense?
M

[hicksy]

Just got back from Cornwall - 850 miles in five days and not a squeek. 65 all the way - AAZ engine. It was the first really long drive and now cant wait to get it through France in August. One thing though, its really noisy, too noisy, a bit of a nuisance. Can anyone recommend someone/a specialist who knows their way around a T25 to get some decent sound deafening material fitted? Does this make an appreciable difference? Not interested in doing it meself, but dont mind paying for a good job

Saw an Orange/cream coloured tin top with an 80/90 sticker at the beach car park at Treyarnon Bay. Nice van that!. Ours was the met red tin top on the grass opposite. Cracking beach

Hi man, I have an AAZ engined caravelle and your right, it can be noisy. Mine has an induction kit (to save faffing around with a modded 1.6d airbox) and stainless exhaust so can be a bit throaty especially on a long run. I have found most noise is road and wind noise really so to prevent this as much as I can I have used flashing tape from wickes to stick to door panels and the side panels and its about £10 a roll and you'll need two.
On top of this I used a roll of foil+bubble insulation. The insulation was about £30 delivered on ebay. I glued it down anywhere it would fit, including the doors, using high temp spray adhesive, then sealed all the edges with silver tape, about £7 a roll on ebay, and again, youll need two really.

To see the results of my insulation check my camper build thread here:

https://club8090.co.uk/forum/viewtopic.p ... 63&start=0" onclick="window.open(this.href);return false;

Best of luck and dont forget to show us all how you got on!

[anaconda]

Thanks Hicksy, the pics were really usefull. I noticed you used flashing tape accrosss the whole width of the engine bump an top sides too. I intend using it on the seat boxing as well.

There seems some doubt regarding the effectiveness of the foil but worht a go for £30.

cheers

[boatbuilder]

Principles of sound proofing:

1. Mass (make the panels heavier)
2. Completeness (don't leave gaps where sound can easily get through)
3. Flexibility (to prevent vibration)
4. Isolation (eg. sealant between roof bars and roof skin, using perhaps a few different carpet materials)

[hicksy]

Thanks Hicksy, the pics were really usefull. I noticed you used flashing tape accrosss the whole width of the engine bump an top sides too. I intend using it on the seat boxing as well.

There seems some doubt regarding the effectiveness of the foil but worht a go for £30.

cheers

The flashing on the engine bump is a caravelle thing. Caravelles are generaly better insulated, due to being passenger carriers as opposed to converted panel vans (as most camper conversions are). To that end, they will have headlining, flashing tape(sound deadening) in some panels, a huge great piece of shaped foam under the cargo floor and carpeted front floor.

Since I have installed the insulation all doors shut quieter and all panels have less of a ring to them. Before putting all of the door cards in I will pack out the panels with the foil backed roof insulation too. Best of luck