Outer Limits 4x4 Board

Hi all,

Still looking around at options for my next set of wheels. Originally, I was very keen on the TDI Disco option, but longevity issues have put me off those.

I am now considering V8 Discos on LPG. I have seen a few around and I know that some setups are better than others in terms of tank locations and capacities. What I am interested in is hearing from ANYONE who has/has had one (3.5 or 3.9) on gas, any issues you had, general economy, and what life expectancy is for a gas fed motor. The vehicle would be used 90% of the time around town, but gentle bush work would make up the other 10%.

I have read/heard that the V8s are usually good for over 300,000k before needing significant attention. Can I expect a longer life on LPG?

Thanks in advance.

I have a 96 Disco 3.9 on LPg.
Get about 20 litre per 100 kms.
Tanks are 2 neatly fitted Scuba tanks slung whee the OEM petrol tank was. I have about 70-74 ltr usuable , range of about 350 to 380 kms,
draw backs are having to fill up regulary on long trips.
Also have a 45 litre petrol tank in right side quarter panel.
At engine oil time oil is remarkably clean, I have had the heads of to fix an oil leak and foung the piston crown very clean as well as the heads.
I have peplace my MAF due to backfires on LPG, but this was due to poor tune.
LPG needs very strong sparks to operate to it potential.
Change plugs more regulary, leads need to be top shape.
Gas runs hoter than Petrol. Plugs need to be 1 number down on specs. timing advanced. This will make your petrol tune run worse.
all in all very happy with the $ savings.

Agree with all that - my 99 series 1 on LPG returns same figures. Occassional backfire is a signal to replace plug leads.

Overall very happy with it.

RE LPG and longivity,
If the donk is in reasonable condition, you can expect to get longer life out of your engine if running LPG. LPG keeps the oil cleaner and does not wash away the oil on the liners which can accelerate wear on cold starts. LPG also normally gives smoother running.

I've had 5 cars on LPG and would recommend it. Having said that, frequent fillups, cluttered engine bays, reduced load storage or ground clearance and the threat of higher excise tax - I now run a tdi disco and I love it. On my run to work I regularly get less than 8lt/100km, and with the tweaks I've done I can hold my own against 3.5v8's upto 90km'hr. Also the poms are reporting over 300,000 miles from their tdi's as long as you change the belts, oil and watch the tappets.

I understand that there are some people getting high (almost reasonable by other diesel standards) mileage out of their TDIs, but there are plenty of horror stories out there.

I want to buy something that has a high probability of keeping its act together for the first 3 years I own it - this one is going to have to be partially financed because I just had my second car stolen in 5 years. The prospect of having a nice to drive, cheap to fuel diesel snuff it and lump me with a $6K rebuild is horrifying! The 3.5 V8s appear to be longer lasting, cheaper to build and easy to find second hand.

This leads me to another question? Is the Disco 3.5 at all similar to the 3.5 that ran in the Rangies, Counties and Stage 1's for all those years? I know there are some very high mileage Rangies still getting about (lots on LPG too).

Cheers,

Mike

RE 3.5 disco's,
I think they are the same but use the latter hot-wire efi system instead of the flapper value, but I'm not 100% sure. I think they have a better transfer box than the rangie for the same period. (I dont think much of the borg warner). For the price, 3.5 discos are fantastic value for money, but LPG would be a must!
Also, for Tdi rebuild - try around $9k !!!

$9K! God only gave me 2 kidneys to sell, so the chances of finding a good "cheap" TDI are about the same as my eye going through a camel's needle... or how ever it goes.

Mike

Mal here from DBW mate give me a call at work buddy

Mal

Howdy Mal,

Will give you a tingle tomorrow...

My ankle is really telling me it's time to give up bikes unfortunately, so it is only a matter of time until I end up with a truck. The hard part is in the choosing!

I bought a 3.9 96 disco today. $8500. I took it for short test drive the day before ran fine on petrol, when i picked up the car filled it up and headed on my hour and a half trip home in stinking heat. The car was idling at 2500rpm and drop off slowly, continued driving with the air con on and the temp gauge came close to the red, turned off the air con and down came the temp. Most the trip home without the air con the temp sat on about 3/4. But theres more, when tried out the the gas it runs well for about ten minutes idles perfect and then it starts to cough and splutter major surging. Its a great car when it runs well. So if anyone has had same probs PLEASE help me out with some pointers.

MONGREL wrote:I bought a 3.9 96 disco today. $8500. I took it for short test drive the day before ran fine on petrol, when i picked up the car filled it up and headed on my hour and a half trip home in stinking heat. The car was idling at 2500rpm and drop off slowly, continued driving with the air con on and the temp gauge came close to the red, turned off the air con and down came the temp. Most the trip home without the air con the temp sat on about 3/4. But theres more, when tried out the the gas it runs well for about ten minutes idles perfect and then it starts to cough and splutter major surging. Its a great car when it runs well. So if anyone has had same probs PLEASE help me out with some pointers.

obviously you have an overheating probelem.
LPG needs water running through the convert to vaporise the gas.
If the line is blocked, ( often crud builds up in the metal hose connectors orifices) , or if you are low on coolant it will will die or splutter on LPG running.
The high idling could be the ECU saying, the engine temp is to high and tires to increase the engine revs to cool the coolant.
Check your cooling system for blockages, thermostat sticking, or an airlock in the engine. A flush out and new coolant could be all she needs.

Just had a 3.9 on gas 1995 Disco with exact same symptoms, the head gasket on the passenger bank had a tiny leak into the cooling system, this would pressurise the system only under load up a hill etc and in turn emptied the water from the converter, displacing it with air/ combustion gasses. This would be the third V8 on gas I've done the heads on this year, all of them with seriously worn exhaust guides, and NONE of them running upper cylinder lubrication, IE flashlube etc.
The head gasket problem in this incidence was probably brought about from age, 220,000km, and the fact that composite gaskets don't last like tin ones. I ALWAYS REPLACE WITH TIN, AS IT ALSO HELPS YOUR COMPRESSION RATIO SLIGHTLY ON GAS.

Regards, JC

thanks guys... most helpfull. how did u test for the haed gasket prob? As it is a bit long in the tooth at 270kms and heats up more going up hills. I could change the head gaskets myself but it looks like i might have to guids done too. Any idea what that will cost me? One other thing my anti lock light on the dash stays on im guessing it needs new pads, the brakes are spongey and shite.

MONGREL,
Unfortunately, the antilock light is actually an ABS fault, and could be a number of things,
1) Too much wheel bearing endfloat, this can push the sensors out of range to pick up the sensor ring signals,
2) A swivel pin problem, IE upper bearing /bush etc worn and too much play in the CV, The sensor ring is part of the CV outer,
3) A sensor itself at fault.

The sensors are the most expensive to replace, the fronts around $500 each, and the rears,(you have to buy them in a pair) are about $800.

I hope a bearing adjustment and a check of the swivel preloads( ABS models have about HALF the preload of the Non ABS ones!!!) will fix the ABS prob.

I think I would be getting the Rad rodded out, as previously suggested, its alot cheaper than pulling the heads if you're not sure that they are the problem
Good luck.

JC

Ok thanks JC. I bought it from a car yard so its going back....

The other issue I have found with LPG is that any slight ignition problem shows first symptoms on LPG, and all might appear to be normal on ULP. Once the LPG running is so poor you can't drive it, then you MIGHT start to see something happening on normal fuel. Something to consider.

Other than one issue on ours, (non genuine rotor failed within 5000km) LPG running has been superb - smoother than ULP actually.