help please knocking on 300tdi engine

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richard prince

New Member
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108
Location
leeds
ive had a slight knocking on my discovery 300tdi.when i listen close it sounds like around number one cylinder(front of engine.)ive been told it could be injectors/fuel pump/piston slap/crank/i cant see it being the crank as its too high for that,er i think.can anyone please help me as im at a loss.and does anyone know a common fault which may cause this.im praying its not had it.it runs perfect no loss of power no missing or lumpy running just a loud knock and its getting louder.thanks
richard:confused:
 
This will be tappets check the clearence with a filler guage and haynes manual if you have neither then tighten them all up so they have slight movement but not NO movement as they will wear very quickly and break???? Let me know how u get on? if its only one it should do this in a regulary patten with a break each time (3-5 sec) if not then its something else.
 
ok m8 i wll check the tappets,but would this cause a definate knock and not a tap.its a hard loud knock but it runs sweet.thanks for your help i will let you know how i get on.
cheers
rich
 
yes this will cause it to knock very loud like there is a majour problem but its that the tappet isn't sitting in its locater properly.
 
clearance is 0.2mm,as I recall.If its worked loose the little cap to the springshaft may have come off,widening the gap and making even more noise/Either way,its just 3 bolts to take the rocker cover off and look
 
ok i will do this unfortunatly i will have to wait for the dreaded weather to stop as i aint got a garage.i will get back to you,and thanks once again
richard
 
Tell a lie,more than three...gotta take the oil breather off too.Still......you can just see it without taking the breather off if lazy/busy/too angry.....
 
hi guys thanks for your help.unfortunatly ive done the tappets and except for no2 and no7 which only needed very slight adjustment the rest were spot on.this has not cured my problem there is no change at all,ive even slackened off the inject but this made no difference either.the noise is a constant knock knock knock with no break in it and obviously speeds up when the engine does,ive tried injector cleaner again no difference.the knock is somewhere around no1 cylinder,it sounds the same at the middle and bottom of the head and at the top of the block.its not the vac pump as thats at the back of the engine im at a loss and worrying.anything else it could be,ive heard other 300tdis whith the same noise but also others which are very quiet compared to mine.
thanks
richard
 
sounds mostly like diesel knock-affected by timing-is it worse cold?
 
Try holding onto the injector pipes. It's possible it could be a faulty injector. I would expect you to be able to feel it knocking on the injector pipe. Has the engine been overheated or run low on oil? 300tdi pistons do like to melt and cause a loud clacking sound.
 
[nomedia="http://www.youtube.com/watch?v=YCvj7S5kN1k"]YouTube - 6.2 diesel injector knock[/nomedia]

has it only started since weather has gone cold.
 
no it started a bit before that but weather its coinsidence or not i dont know it has definatly got worse over the last 4-6 weeks.ive listened to that on utube and its a similar sound but louder
 
You could try a diesel centane booster-if it quietens down you know its diesel knock related
 
ive used wynns diesel injector cleaner i think it is a tiny bit quieter but not loads
wheres best place to get em everywhere ive looked there about 60 suid each or is that about right
 
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