Problem with air filter on Range Rover.

[blue190]

Sorry to darken these pages with a non-MB problem but I'm intrigued by a problem my step-father has had with his Range Rover. As far as I can tell he accelerated hard which was followed by a bang. When he got home and opened the bonnet he found the lid of the air filter housing no longer bolted to the rest of it while the air filter remained in place, the filter is an after market k+n btw. I don't understand what could have happened to cause this. If it makes any difference it is a 1995 P38(Mk2) 4.6 HSE with a recently fitted LPG conversion. Any suggestions?

 

[Ade B]

You could try here

http://www.my90.co.uk/cgi-bin/lpgforum/discus.cgi?pg=topics

hth

Ade

 

[bolide]

Classic backfire scenario. That's why the plenums on those cars are huge cast ally jobs. Either the K&N, or the LPG (or both) has screwed up the fuelling

Nick Froome
www.w124.co.uk

 

[blue190]

Classic backfire scenario. That's why the plenums on those cars are huge cast ally jobs. Either the K&N, or the LPG (or both) has screwed up the fuelling

Nick Froome
www.w124.co.uk

That sounds about right, I went with him to Bristol and back from Pembrokeshire last week and it does seem to backfire rather ferociously when running on lpg and low on gas. Thank you.

 

[Dieselman]

The backfiring has probably blown the air volume flap the wrong way so it may not be working anymore, and could be damaged.


This is one of the downsides of LPG installations.

 

[blue190]

The backfiring has probably blown the air volume flap the wrong way so it may not be working anymore, and could be damaged.


Would this be causing a whistling?? I will tell him to get it checked.

 

[Glenn Smith]

Sorry to darken these pages with a non-MB problem but I'm intrigued by a problem my step-father has had with his Range Rover. As far as I can tell he accelerated hard which was followed by a bang. When he got home and opened the bonnet he found the lid of the air filter housing no longer bolted to the rest of it while the air filter remained in place, the filter is an after market k+n btw. I don't understand what could have happened to cause this. If it makes any difference it is a 1995 P38(Mk2) 4.6 HSE with a recently fitted LPG conversion. Any suggestions?

Probably a fault with the fuel or ignition system, most likely with the lpg conversion.

 

[Ultymate]

Deffinately caused by backfire common on LPG conversions many current conversions include mods to air cleaners to prevent such occurences

 

[Vlad]

Thats very strange as you should not get backfires from a modern sequential LPG gas conversion which has a seperate injector per cylinder.....was it a brand new system that he had fitted and if so was it installed by an LPG Association member?

I can only assume that its one of the older systems....I've just had another Discovery converted, again with a sequential injector system and I've never had anything but reliable service from these conversions.....on the modern systems you can't even tell when it switches over between fuels.

I suggest that he gets the system checked over pronto before he does any serious damage.

PS: as its a 4.6 you need to keep on top of maintenance 100%, especially with regards to the coolant which must run the correct anti-freeze at the correct ratio...these engines suffer from porous blocks and can be quite fragile as the amount of metal between the bores is quite thin due to it being taken out to 4.6...in other words the block is right at the maximum it can go in terms of bore

 

[TVRTASMIN]

I'd concur regarding the porous blocks.
My 5.2 Litre TVR suffered from this.