Landrover Discovery Fault

[YellaBelly]

Any Disco experts out there?

Just forked out for a new tyre for the truck as I'm getting her sorted ready for the winter time, went to start it as I hadn't used it for a week, and got a loud knocking from the engine. Intermittent then it seemed to go away for a few seconds, then came back again. It seems to lessen with revs but I am reluctant to give her too much throttle until I know what it might be

I drove it round the yard and the noise was still a little intermittent. Seems to be worse when I drop the throttle so my fear is that the Big ends are the culprit

I'm not 100% and I always thought that they would give a gradual increas in noise and not go suddenly?

Anyhow, anyone got any ideas?

I might try and record the noise tommorrow and put it on here to let folks know what it sounds like.

Any help really appreciated.

[paintman]

Griff might be able to help you.....think he's got 3 of them!

    Tony

[fullpint]

Found this on a forum?
http://www.landroversonly.com/forums/f40/new-knock-rattle-started-today-58900/

[YellaBelly]

Thanks for that Steve.

After my neighbour had a look, we removed the aux belt and the noise went!!

The belt runs the water pump, alternator and power steering pump. I don't think the water pump would make such a heavy knocking noise so I'm guessing the alternator or steering pump. Neither seems to have any play I can detect, but my steering pump reservoir was about 1" low (I had not tightened the cap properly at the last check ). I topped it up, refitted the belt, and the sound had gone, but returned after a few minutes very occasionally and mostly on the overrun. So I guess low fluid may not have done the pump any favours? Although it was not that low. Either that or the alternator is pooped?

Change of diagnosis......

Just taken the belt off again, and the noise is still there

Not sure what to try next now?

[fullpint]

sounds like you need a few pairs of ears to locate just where the noise is coming from.. Thrust bearing?

[YellaBelly]

Definitely not thrust bearing chap, I've managed to record the noise, not brilliant but hopefully detectable.
Link: around 11secs to 30 secs then again from around 1:10 to 1:40

[fullpint]

Almost sounds like a valve sticking...

[YellaBelly]

I guess if it was sticking enugh to touch the piston that might not sound too cool!

I'll whip the rocker cover off and have a butchers.

Edit:  Can't see anything obvious, but then I guess I wouldn't.

[fullpint]

Fire her up and try the good old screw driver to the ear test. Should be able to locate the valve if it's that..

[peterw]

Sounds like a normal diesel Landy to me !!!!!!!. Seriously though, could be exhaust touching something on the chassis and only rattling on over run, or something like that.

[YellaBelly]

Nope! Definitely sounds very metallic and internal but I can still check for that too though thanks

[fullpint]

Is it safe to whip the rocker cover and start her up just for a few seconds? Ok may get a little messy but you may hear where its coming from...

[Griff]

Afraid my 3 are all petrol.  I would be thinking oil pump of pick-up or water pump though....   Is the oil light on?

[YellaBelly]

Oil light is off mate, and can't be the water pump 'cos the moise is still there with the ancilliary belt off. Not sure what you mean about the oil pickup pipe?

[Hairy Santa]

Iv'e got a stethoscope over here if you want to borrow it - might be able to track down the noise

[YellaBelly]

Cheers Pete. I might take you up on that when I get back from India.

JB