Disco diesel noise

I have a 1994 disco and it has ALWAYS had a noisy engine and I have never found out how to reduce it. Any ideas apart from changing to petrol? I make sure the tappets are right and the oil is the the right level but apart from that?
thanks

What noise?

Is it a diesel knocking? Like noisy "pinking" clattering noise?

This happens when you deck the pedal suddenly and when working under load.

If this is it, BACK OFF the timing of the injection pump a couple of degrees until it stops.

You may need to do this 2 or 3 times.

The clattering is not good for the engine. Knocks hell out of pistons, rods, big ends, etc.

CharlesY

Check the left hand side of the engine block, under the exhaust manifold, for sooty deposits. An exhaust leak from the block-manifold gasket would make a hell of a noise. Might be worth checking the manifold-down pipe joint too whilst ur under there, i've seen both leak.

Is it a 200tdi or a 300tdi? Mines a 200tdi and it's noisy but I thought they were all noisy. As long as it's not a metallic banging/clattering it's ok isn't it???

jbarlow said:

Is it a 200tdi or a 300tdi? Mines a 200tdi and it's noisy but I thought they were all noisy. As long as it's not a metallic banging/clattering it's ok isn't it???

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Definitely NOT!

Any sharp harsh clattery noise, or clinking, chinking or squealing, is BAD NEWS.

On tickover a 200tdi or 300tdi or any other Landy diesel really should run quite smoothly, with NO nasty noises at all.

Next is to "blip" the throttle. This should hoick the revs up smartly but should NOT induce nasty noises as above.

At any running speed, there should not be nasty noises.

After a while you'll get to know what's an ordinary "who cares a toss" noise, and what's a "Bloody Hell ... Switch OFF quick" sort of noise.

With any luck you'll learn to tell the difference before your engine disintegrates. It's cheaper if you do.

Buy a special stethoscope with a rod probe. Great tool for working out noises in engines.

CharlesY

CharlesY said:

Buy a special stethoscope with a rod probe. Great tool for working out noises in engines.

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you could also use a big long handled screwdriver, put your ear on the end... not quite as effective but worth a go.

funny this should come up because i get a knock when i am not under load, top end on mine seems quiet but was thinkng maybe the shells could do with replacing but that knock would get bigger underload if it was it usually happens when on light throttle but when i gun it all goes quet and all i can hear it the turbo whistle away nicley. is all i have mentioned a good or bad thing???

Well I had a listen under the bonnet and revved it up and I think mine is ok, it is loud but it runs smoothly, there is no banging, clattering, squeeling or anything.

200's have always been noisy ffs, thats why they bought out the 300, cos it were quieter

Beware knocking noises that tend to go away under load.

Big end shells getting worn tend to behave that way, whereas main bearings tend more to make a deeper rumbling noise all the time.

Sometimes it's better to shove in a set of big end shells rather than wait for the shaft to get hammered till it needs a re-grind.

Big End shells are quite easy to replace.

CharlesY

speaking of the 300tdi i have been offered one that came in part ex v8i on gas with certificate FLRSH m reg on 108k and its got me thinking but i love the reliablility of my deisel hmmmmmmmmm.
gonna have a look at it tomoz as i can pick it up for 2k so ill see how she feels when i take it out.

just noticed in the last couple of days, a kind of knocking noise under bonnet??? only seems to happen when going downhill can anyone advise thanx???

its the cat tryin to get out

That did actually cross my mind!! Unfortunately no cat under there!!

Before replacing the big end shells an oil pressure check using a decent gauge might be worthwhile. My 200 is noisey but it is general noise, I know tappets are fine oil pressure is approaching 4 bar, the noise is the same after a year of ownership.

regards

Dave

If the engine goes fine, and if the "knocking noise" happens in the same circumstances most times, probably you can just ignore it.

No-one can diagnose a noise accurately without hearing it, but the way you are telling it, the engine goes fine.

With any luck it will be something inocuous like a little piston slap, which usually happens at slowish speeds, and taking your foot off the GO pedal.

These engines have a reputation for being reliable, but as someone pointed out, they also have a reputation for being a bit noisy.

CharlesY