Rough Running

[nervous]

Hi Folks,

my 2002 4.0l petrol RR p38 has started running really rough- does anyone have any clues as to what commonly causes this? It gets better when warm, but still isnt as smooth as it should be.

I had hoped that it might just be the dis' cap, rotor arm, and HT leads (ie cheap, easy fixes), but my local LR spares place suggests that the engine in mine doesnt have a dis' but instead seperate coils, meaning it isnt likely to be that, sadly.

If it helps at all, the plugs and filters were replaced 10k ago, and it hasnt suddenly lost coolant or used lots of oil either. The car is currently on 108k.

So, anyone got any likely culprits/ suggestions/ ideas? or am I going to have to pay to get some monkey to plug my car into a computer to tell me that 'it might be one of the sensors, or something'? And if so, can I access the diagnostic myself and translate the codes? I really resent paying 60 quid for that sort of thing

Id appreciate any ideas you might have, thanks in advance for your help

[BLUETHUNDER]

sounds like a duff coil pack.Needs further investigating.

[nervous]

thanks BT- how do I investigate that? is it just one coil pack or one per plug?

[pontypool]

I am sure that you have checked these obvious things, but in case not..

Is there a hole in the exhaust anywhere? made mine rough as a dog until the hole got big enough to notice the noise, once fixed ran silky smoothly

Is it using any water? I hope not, but could be the infamous P38 engine problem

Oxygen sensor need replacing?

[BLUETHUNDER]

nervous said:

thanks BT- how do I investigate that? is it just one coil pack or one per plug?

I'm afraid it needs a specialist.Worst case scenario is the block problem,as previously mentioned.

[nervous]

thanks Chaps, Ill have a look at those things tomorrow and report back.

[nervous]

sorry to necropost this, but the rough running is getting much much worse, but no one seems to be able to diagnose it.

Theres no holes in the exhaust and Im only using about 5mm of coolant every three months, and no oil.

anyone got any ideas? please?

[Tim Mosley]

Funnily enough, Mine started this at 110k. Felt like it was gonna cut out at times and like it was running out of fuel.

I had the oil changed to 'High Mileage' oil, changed all the filters and added an upgraded air/induction filter.

Was fine after that.

Similar car aswell, P38 4.0 V8, Although mine is 2 years older at a W/2000.

[nervous]

ok, I can do that. Thanks chum.

fingers crossed please