SPendrey Posted September 2, 2013 Share Posted September 2, 2013 Hello again, I realise this is like asking how long a piece of string is, but I'd like 60 seconds of your time to listen to a new knocking noise my Disco has started making. It is different to the typical injector/pump noise, and seems very much to be on the exhaust side of the engine. The first 30 seconds really illustrate this well, the last 30 are just upping the RPM again (although I don't know what to because I'm engine side). I recorded the sound while moving from the injector side to the exhaust/turbo side to illustrate the difference, the noise is much clearer at the exhaust side. It is also present both with and without the aux belt driving the water pump, alternator etc. It appears to be most noticeable under load and early in acceleration, as the revs increase above 1800-2000 RPM the noise either goes away or is indistinguishable from the general 300TDi barrage of decibels. I know a couple of mechanics locally, but I'd like to have some idea of possibilities before approaching them, so I sound like I know what I'm doing! Any thoughts? Regards, Scott Quote Link to comment Share on other sites More sharing options...
Tetsu0san Posted September 3, 2013 Share Posted September 3, 2013 Pop off the rocker cover and check everything is tightened down on the rocker shaft and check the valve clearances. Might be as simple as that. Quote Link to comment Share on other sites More sharing options...
Boydie Posted September 9, 2013 Share Posted September 9, 2013 Try removing the vac pump (plug the hole up with a lint free rag before restarting the motor)- the cam shaft has two lobes that operate the vac pump and its the cause of 20% of the engine noise. I just wish there was room on the 300TDi to run one off the alternator ! The other culprits are the fuel transfer pump and poorly set tappets - and when did you last change your timing belt and did you install the newer design pulleys? Quote Link to comment Share on other sites More sharing options...
SPendrey Posted September 9, 2013 Author Share Posted September 9, 2013 I wondered about the vac pump, it is showing signs of a very small leak/muck accumulation on one edge. However, it is on the wrong side re. the noise. In terms of the timing belt, well, I've not changed it in the 5 years/20k miles I've owned the vehicle, but it is on the to-do list. Quote Link to comment Share on other sites More sharing options...
Rangy35 Posted September 9, 2013 Share Posted September 9, 2013 To me it sounds like a tappet, on the top of the valves there is a little cap, this aids in fighting friction and wear, maybe one of them had enough and broke.......yes seen this alot, dont worry about the pices that are in the sump they will not be picked up and pumped through the engine because they will be to big for the strainer to fit through. Get yourself a pice og magnet or magnetic sump plug and at some stage when you do a oil change and you remove the plug it will be stuck on there. It could also be a failed cam follower seen that too but very rare and the head has to come off to renew it. IMO and experiance could beway off.............like the green boost hose. Quote Link to comment Share on other sites More sharing options...
SPendrey Posted September 9, 2013 Author Share Posted September 9, 2013 like the green boost hose. Thank you! Well, after a little online digging around I 'adjusted' the tappets. To be honest, I couldn't believe how much difference there was between a 0.2mm feeler and the actual movement on each one, so I just tightened them all a little bit. Now, I think noise has reduced, maybe even gone, but it is hard to tell! The snorkel for starters is a deep rhythmic tone... trying to be objective rather than optimistic! Will drive it to work tomorrow to see. PS. All the little valve cap thingys are there. Quote Link to comment Share on other sites More sharing options...
SPendrey Posted September 11, 2013 Author Share Posted September 11, 2013 Well, to close the subject, tappet adjustment seems to have resolved the knocking noise! Not sure how adjusting little things at the top left of the engine stop a knocking noise on the mid-right, but there we go. Quote Link to comment Share on other sites More sharing options...
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