300tdi strange air leaking noise

Hey guys - yes sorry for the quality of the video!

The tinny rattle is just a general defender noise! Sorry it's hard to hear the noise in question, the quality isn't very good.

If it is possibly the viscous fan, what should I be checking / replacing? However would a viscous fan related noise fluctuate with engine revs?

I looked up viscous fan problem on tinter web and tested the fan and coupling this morning. Seems to all be working correctly, with no odd noises. I had an hour or so so I ripped apart the air intake system again, all seems sweet as a nut. Definitely no leaks. She is going in for an MOT tomorrow so I'll ask the guys to have a look.

Listening to it through a decent stereo and the noise that I think that I'm hearing sounds a little like something rubbing, perhaps on a propshaft. Anything loose near them? Or the handbrake drum. Maybe something stuck between brake disc and guard.

Agreed it does almost sound like binding brakes or something, strange thing is it doesn't make any noise until about 20 or 25 mph and then gets incredibly annoying! I've been out and checked the handbrake drum and propshafts, everything seems fine, I even sickened the bolt on the handbrake drum right off so the handbrake was definitely not binding. Noise still there. I checked all the brake discs too to see if anything was stuck and everything looks clean and tidy.

It almost sounds like a combination of the heater blower blasting its head off and the radio when its not tuned in fairly loud. But i can't turn it down haha! It sounds so convincingly of pressurised air escaping from the centre of the dash the only thing in behind there is the EGR vacuum thingmy bob, so I've tested all the vacuum lines and taken the unit off and tested that too, all ok. The EGR is removed so just to confirm I have a line coming from the engine side of the air filter housing in the top port, the middle port is capped off and the bottom port has a vacuum line from the brake servo. Is that correct?

I have had a post on here previously that I never really found a solution to - the landy seems to be a tad underpowered and unresponsive. With a rough idle on start up when cold. Runs ok when warm though just seems noticably down a little on power compared to others I have driven. I have a decat and alisport intercooler too so really it should be pretty quick (I know that's not what they are all about) but torque seems low too.

Should I be worried it's a compression thing and there is air escaping from the engine? Seems odd that it doesn't fluctuate with engine revs or load though. Odd .... and sorry for waffling on. I am sure you guys can appreciate it's fairly annoying though.

One thought. How far forward is your roof rack if you have one? I have roof bars and they were making a he'll of a racket until I moved the front one back away from the slope of the roof. Noise gone.

I've got a fairly beefy roll cage which has a section that runs above the top windscreen with a led light bar there too. There is also a section of roll cage that runs over the front gun flaps so they don't open fully. The noise is very constant and doesn't change with strong gusts of wind, I've also tried stuffing the spaces with wrags, and the noise is still there. Good shout though.

Long shot. I had a difficult to pin down scraping/rubbing noise. It turned out to be the transfer box, although it sounded if it was coming from the front brakes. Try knocking the gearbox and then the transfer box into neutral when driving.

By knocking do you mean no clutch? Just bang to out of gear?

It was in for its MOT today, the guys just phoned and said over all it's in great condition (which makes me feel good!) just a couple of bushes to replace. I asked them to have a look at the noise and they think it might be coming from gear box / transfer box. I've only had the lady for a year and I haven't changed the gearbox oil or anything so I've asked them to give her a full service while there at it. Hopefully that will shed some light.

Hope they cure it nothing worse than annoying noise.

danny6801 said:

Hope they cure it nothing worse than annoying noise.

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Shut you gob then

Your gob you mean. Oh forgot that's how you lot speak in Robin hood land

Forbes said:

By knocking do you mean no clutch? Just bang to out of gear?

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Use the clutch to disengage gears (obviously). Best done on a straight road with no following traffic to annoy cos you'll have to stop to re-engage the transfer box.

faircot said:

Use the clutch to disengage gears (obviously). Best done on a straight road with no following traffic to annoy cos you'll have to stop to re-engage the transfer box.

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Faircot! Genius! I finally got round to testing the transfer box as you described tonight. Guess what!? No wooshing, hissing sound when the transfer box is in neutral! So the question is now... What's wrong with it? Transfer boxes sound expensive....

Change the oil in it for starters

Thanks Flat, I've just had replacement oil in the gearbox and transfer box last week as part of a service and MOT. It didn't make a difference unfortunately. It was a garage job but they didn't mention anything odd.

Hmm

Handbrake rubbing slightly?

The handbrake was loose and was adjusted properly for the MOT, so we can probably rule that one out.

Is it possible that bearings in the transfer box are worn?

There is a bit of "the defender knock" going on when you don't put the power down smooth or have release the clutch too quick when changing gear.