Discovery hissing noise - help please..

tommywiseau

sorry, this is a bit on the long side..
got the use of a 99 tdi discovery yesterday. after a 1 1/2 hour drive this morning parked it up and could hear a hissing noise around the rear drivers side tyre.. quite a loud hisssing noise but i kept an eye on it to see if the tyre was dropping i.e. puncture..
pretty sure the tyre wasn't deflating but i went off to get a can of tyre-weld anyway, returned 10 minutes later and it was still hissing BUT the tyre has no signs of deflating!!!?? used the tyre-weld and the hissing stopped a few minutes later..
just went and checked on the discovery there ( 8 hours since hissing and been parked up all day) and all seems fine, tyre hasn't delfated at all.. asked somone today and they mention it could have air suspension?? or was it most likely a puncture..? the hissing was loud so my guess would be it wasn't a puncture as the tyre didn't delfate one bit. i'm not mechanically minded at all ,incase you couldn't tell..

101sean

If you had a badly punctured suspension air bag, the vehicle will droop on that corner. However if it's only a pin hole, the hissing may be loud but the compressor will keep it inflated. The airbag may even only leak intermittently, depends where the hole is.

Whatever, it needs sorting, airbags are cheap and easy to replace but the compressor will burn out if ignored and they aren't cheap. If it's still on it's first set of bags, as a 99 it's way overdue for one to fail.

elius

If its 99tdi surely it would be coils?

101sean

Didn't spot the Tdi bit

OP could be mistaken, Td5 Discovery II came out in 1998.

_Conrad_

101sean wrote: »

Didn't spot the Tdi bit

OP could be mistaken, Td5 Discovery II came out in 1998.

it's still a tdi engine anyway, in that people call any turbodiesel tdi in this country, like the JCB thing, and hoover.

First thing that sprung to mind with me anyway was "air suspension leak?"

Mycroft H

101sean wrote: »

Whatever, it needs sorting, airbags are cheap and easy to replace but the compressor will burn out if ignored and they aren't cheap. If it's still on it's first set of bags, as a 99 it's way overdue for one to fail.

Sound Advice there...


Airbags are only bout 65 quid from paddocks the last time i checked. Go replace them

And as mentioned continued use could burn out the compressor - its designed for self leveling and the odd blast to keep the pressure high, but not to keep a heavy disco level with leaky suspension, its like keeping a balloon inflated with a hole in it

jwshooter

my TD5 has the same its the active cornering system .

tommywiseau

thanks for the help lads. had her on a 400 mile round trip down around kerry at the weekend, no issues whatsoever. even got in a little off-roading on valentia island! no hissing since the 1st time it happened, so i guess ive been lucky but i will be looking into it. the discovery is a '99 'gs' model 2.5 tdi. im not sure if its a 1st or 2nd generation disco to be honest!!

101sean

Should be a pre-facelift Discovery 2 with a Td5 5cyl diesel. That description will usually be good enough for finding parts.

GS is just a trim level.

Wheelnut

It's a bit late now, but the first action should have been to check the tyre pressure. They're big stiff tyres, made for hard work, off-road etc, so they could lose a lot of pressure without looking "soft" to the naked eye.