P38 ticking on gas

[nunziom]

Hi,
I have recently purchased my first range rover and love it. Recently it has been doing something a little interesting. On a drive from Melbourne to Sydney I noticed that when running on LPG the engine was making a ticking noise (almost like a stuck lifter). This ticking would disappear when running on petrol (not straight away - after 10 to 15 minutes). I've been running the car on petrol for the last week and no hint of noise. When I start the car on LPG there is no ticking noise....
Anyone got any ideas??? :confused:
Cheers
Norm

[bee utey]

Does the ticking go away when you back off? Then it is likely a weak head gasket, LPG runs slightly hotter and would lift the head more.

[400HPONGAS]

bee utey , did you mean Head gasket instead of Exhaust gasket ?? Sounds very much like the standard exhaust gasket leak/blow out .

[It'sNotWorthComplaining!]

My sequential gas has a slight ticking noise, I was told by previous owner that it's just the open and closing of the gas injectors, I only hear it when in the passenger seat. Who knows

[nunziom]

Thanks for the replies.
The ticking is only really audible when at low revs (under 1500rpm). No difference when accelerating, cruising or backing off. Interestingly, I've been running the P38 on petrol for the last few tanks and last night ran it on LPG and no ticking. I'll see how long that lasts...
Cheers
Norm

[bee utey]

Probably the best thing to do is when the ticking starts, pull over, open the bonnet, see if you can narrow down the area of the ticking. I know some LPG injection systems tick quite loudly when hot, but yours does it for a while after you go back on petrol? Perhaps 400HPONGAS is on the money, and an exhaust gasket is letting go. Try tightening up any exhaust manifold bolts you can reach.

If its really inside the engine, and actually a lifter, perhaps its time to try a better engine oil?