Bongo Fury

Hi
I have 2005 2.0l. It is VERY noisy. I would say that it is induction noise and although its a bit annoying when accelerating it is defening at 70mph on the motorway. I have searched this forum for clues as to the cause and possible fix but everything I have read tells me mine is much worse than others. I have read about thermostat fan and clicking relay, well I would never hear them except on tickover. I also have a 1996 2.5 diesel and although it is not quite it is a pleasure comapred to my very expensive new purchase. Has anyone else had this problem, or better still fixed it (other than selling up).

Has it been like that since you had it? I test drove a 2.0 once and did find it quite noisy especially as it needed to be driven fairly hard to get it going. The V6 is very quiet at when idling or pootling around, but quite noisy when you get the revs up and is probably the same as the diesel once you get above 30 or 40 as the road noise far outweighs any engine noise.

Yes it has been the same since I have had it about 500 miles ago. I took a test drive and found it noisy but was told that it would be fine cruising, well it is not and with a slight hill at 70 it is out of order. It is slightly better if you encourage it to change down and the revs go up a bit. It sounds to me like a huge resonance just at that speed. It of course happens at other speeds in other gears and other throttle openings. It just seems to resonate when revs and throttle opening coincide.

Hi
You say induction noise???...now silly as this sounds, have you checked the air filter , and all the piping before the filter...a possible piece of plastic bag in the intake pipe, if it's as tortuous as the diesel intake pipe, or missing / damaged air filter
Cheers
Helen

Hi gayhalo,

As Helen has said,check that the filter housing is clipped down properly etc,also worth checking that the By pass Air Control Pipe is secure and intact.Also I would check your road speed to rpm is within reason.

This should give you an idea of the ratios...


Gear Ratios
(mph/2000rpm) for each
gear.
1st – 11.2MPH
2nd – 20.4MPH
3rd – 32.0MPH
4th – 50.3MPH

+/- 8%

PS Thanks for the PM reply,very helpful.

Cheers.

Thanks both of you.

I have checked that all the pipes just before and after the filter are ontact. I have not checked inside the pipes but will do. I have checked the filter and it is a new paper fiter that looks fine. I have made sure the seal at the top of the filter is intact and the top is clipped down properly. I tried stuffing sound proofing ( a dog bed) around the intake for a short run and that made no difference. I moved the bed and wrapped the air filter in it..... no difference.
I will look for the "bypass pipe" and I will check the other pipes for blockage. I will check the rpm but it all runs wel and changes gear when expected.

This sounds (sorry) just like a proof of the myth about diesels being "noisier" than petrols - they are - but usually only at low revs and when pootling about. Diesels tend to have roughly the same level of engine noise at all revs because their air intake is wide open at all times - they don't have a throttle butterfly valve that opens and closes to control the revs like a petrol.

As the butterfly opens on a petrol the intake noise (unless the air inlet trunking and air filter housing etc. is very well designed) increases noticeably as engine revs rise.

That said it sounds (sorry again) as if you have a leak or a break somewhere in the inlet trunking or one or both of the seals around the engine covers the seats are mounted on isn't sealing properly for some reason.

it could be the 1st section of the exhaust pipe after the exhaust manifold.
this verticle piece is twin wall, and the inner pipe splits and the noise reverbs on to the outer pipe that surrounds it. this cannot be seen until you cut/remove the outer layer then weld it up and replace the outer.
it sounds like a manifold stud gone, a sort of put-puting sound, but could just sound loud if its split in a slighly different spot.
according to a bongo specialist this is very comon on the 2 ltr.
pm me if you need further info, one club member i know has had this on their 2 ltr.

gayhalo wrote: It just seems to resonate when revs and throttle opening coincide.

Does it have the undertray fitted?

Hi
No it does not have an undertray... my diesel does..... does it make a big difference?

gayhalo wrote:Hi
No it does not have an undertray... my diesel does..... does it make a big difference?

Should do..! Check out how this thread resolved... http://www.igmaynard.co.uk/bongo/forum/ ... =belly+pan

Ok I spent an hour or two checking things over. I was wrong, it does have a two piece under tray. My exhaust has plain pipe after the manifold with the Lamba sensor and Cat in it. The manifold had a bolted on heat shield which is all tight and with my good ear I can hear no exhaust noise at all. I do not appear to have a manifold bolt sheared. I have some people to contact when they are back to work about the exhaust so i will see
So back to the input side. All the pipes are connected and I can find no sign of any damage running my hands over them. I found something I did not expect. There is a black plastic box connected (via a t joint) to the input pipe about a foot in front of the air cleaner, anyone know what this is for? I checked and my diesel has one the same.
I have suspicions about the corregated pipe that connects the engine to the air cleaner. It is a very thin moulded pipe which is great for flexibility but may vibrate with the induction noise and pass it to the underneath of the seat. I have tried a piece of plastic pipe inside the rubber which I think made a little reduction in the noise. The pipe I had to hand was too big so i had to cut a slice out of it lengthways and it is not very tight in the pipe so it could still be vibrating.
The search goes on.

Hi there

We have a 2l petrol 2003 AFT. Althgough it is not at quiet as our other car (mondeo), it certainly does not appear to be as noisy as your one, either at low or high speeds. Radio does not require adjusting or voices raised particularly at high speed. As well as checking all of the points noted above, make sure the clips are tight and the engine deafening in place on your engine cover. The undertary, which you are missing also has sound deafening on it. Do you know why it has been removed? I have driven both diesel and petrol variants, and our petrol is definitely quieter at low speeds, and not discernably different either way at high speed (70mph). What sort of fuel economy do you get? It sounds like you have a problem somewhere, but I can understand how difficult it can be to measure and resolve
Keep us posted on your findings.

all the best

David

gayhalo wrote:Ok I spent an hour or two checking things over. I was wrong, it does have a two piece under tray. My exhaust has plain pipe after the manifold with the Lamba sensor and Cat in it. The manifold had a bolted on heat shield which is all tight and with my good ear I can hear no exhaust noise at all. I do not appear to have a manifold bolt sheared. I have some people to contact when they are back to work about the exhaust so i will see
So back to the input side. All the pipes are connected and I can find no sign of any damage running my hands over them. I found something I did not expect. There is a black plastic box connected (via a t joint) to the input pipe about a foot in front of the air cleaner, anyone know what this is for? I checked and my diesel has one the same.I have suspicions about the corregated pipe that connects the engine to the air cleaner. It is a very thin moulded pipe which is great for flexibility but may vibrate with the induction noise and pass it to the underneath of the seat. I have tried a piece of plastic pipe inside the rubber which I think made a little reduction in the noise. The pipe I had to hand was too big so i had to cut a slice out of it lengthways and it is not very tight in the pipe so it could still be vibrating.
The search goes on.

Hi this might help,have a look at the Fresh Air Duct,this is common to all models.




http://lushprojects.com/bongopartsmk2/c ... no=.html#1

Thanks teenmal. It looks like there are two plastic boxes!!! and I have a couple of small pipes to check out up near the engine.

and
Thanks David. Our posts must have crossed as I have discovered I do have an undertray.

My other car is a Volvo V70 CX and I may be a bit spoilt as it is virtually silent at 70 mph (except tyre noise) but believe me I am talking about a lot of noise. I can just drown it out with the radio FULL volume. Thanks for giving me the radio yardstick as I am now sure other 2.0l Bongos are MUCH quieter than mine.

I will certainly keep this thread going to its conclusion.