Sabre Posted February 18, 2013 Share Posted February 18, 2013 My son's TDi developed some tappit noise recently. When we checked clearances, they were all a bit loose, but no 7 had quite a big gap We adjusted them, rechecked, and they were fine. Today he complained about another loud tapping sound on the right hand side of the engine, and some loss of power I took it for a short ride, the sound of the engine changed suddenly and sounded like it was running on 3 cylinders. And then the loud tapping sound made itself heard, as well as a knocking sound towards the front of the engine We towed the Disco back home, and just removed the tappit cover to see if anything looked out of place. That self same no 7 tappit has a clearance of about 2mm ! We removed the injectors as well, but visually they look OK, although they have done 300 000km Any idea why the tappit clearance has increased ? Any idea on what might be wrong with the engine ? (Yes, I know it's difficult to identify the problem from the above description, but maybe somebody had a similiar experience ?) All help appreciated Quote Link to comment Share on other sites More sharing options...
western Posted February 18, 2013 Share Posted February 18, 2013 are the valve caps in place, 8 little discs in the spring retainer centre, valve clearance is 0.20mm all 8 valves cold engine. if it's changing maybe the ball of the adjuster is worn or the nuts are not holding when tightened. Quote Link to comment Share on other sites More sharing options...
Boydie Posted February 19, 2013 Share Posted February 19, 2013 I set mine at 0.015 - sert with the engine stone mother-less cold I found 0.20 was too much and when hot (normal running temperature) there was around 0.02-4 clearance, a good gap for occassional high revs. Quote Link to comment Share on other sites More sharing options...
mmgemini Posted February 19, 2013 Share Posted February 19, 2013 Valve cap missing Quote Link to comment Share on other sites More sharing options...
Sabre Posted February 19, 2013 Author Share Posted February 19, 2013 are the valve caps in place, 8 little discs in the spring retainer centre, valve clearance is 0.20mm all 8 valves cold engine. if it's changing maybe the ball of the adjuster is worn or the nuts are not holding when tightened. I do not know what the valve caps look like. I had a look, below every lifter sits a little round object on top of the valve stem. All the valves have that Quote Link to comment Share on other sites More sharing options...
Sabre Posted February 19, 2013 Author Share Posted February 19, 2013 I set mine at 0.015 - sert with the engine stone mother-less cold I found 0.20 was too much and when hot (normal running temperature) there was around 0.02-4 clearance, a good gap for occassional high revs. Yes, I set the valve clearances at 0.2 with the engine cold. (I think the owner's manual state the same clearance for hot and cold) Quote Link to comment Share on other sites More sharing options...
Mo Murphy Posted February 19, 2013 Share Posted February 19, 2013 Check that the rocker shaft is not broken. If the threads in the head for the rocker shaft studs strip, the rocker shaft can move and break, giving erratic clearances and valve overlap. Mo Quote Link to comment Share on other sites More sharing options...
Sabre Posted February 19, 2013 Author Share Posted February 19, 2013 Check that the rocker shaft is not broken. If the threads in the head for the rocker shaft studs strip, the rocker shaft can move and break, giving erratic clearances and valve overlap.Mo Thanks Mo, I just checked that, and the shaft is still OK Quote Link to comment Share on other sites More sharing options...
elbekko Posted February 19, 2013 Share Posted February 19, 2013 Did you actually take the shaft out to check? Definitely check the shaft mounts haven't come loose too. Quote Link to comment Share on other sites More sharing options...
Boydie Posted February 22, 2013 Share Posted February 22, 2013 This is one of the reasons I'm looking at converting the engine I'm building to hydraulic lifters, adjustable tappets are Quote Link to comment Share on other sites More sharing options...
Sabre Posted February 28, 2013 Author Share Posted February 28, 2013 Did you actually take the shaft out to check?Definitely check the shaft mounts haven't come loose too. OK feedback on this. I took out the rocker shaft, pulled, twisted, nothing ! OK, now that I have determined that the shaft was intact, and nothing else showed up, we decided to go deeper. Removed the head. Pistons 3&4 were quite clean, with whitish markings on the top. I took out the pistons (the bores are so good, honing marks look like they had never seen a piston !), still nothing. I then found a local guy that works on LR's and who knows the TDi's well. I told him about the strange noise and loss of power. "Oh", said he, "You got a broken rocker shaft" I told him that the shaft was removed, checked, shaken, nothing. "Take it apart" said he. So into the garage I went, picked up the rocker shaft, and................. it fell apart in my hands !!!!!!!!!!!!! Broken off clean in one of the landings OK, "I told you so" is in order now . I never knew I could feel so relieved to find a broken part What this has taught me is to add a spare rocker shaft to my spares bin when I go bushcamping And to believe the good advice that the fudi's on this forum give Quote Link to comment Share on other sites More sharing options...
Mo Murphy Posted February 28, 2013 Share Posted February 28, 2013 God, I hate being right Glad you've resolved it. Breakage often follows cam belt failure. Mo Quote Link to comment Share on other sites More sharing options...
Ari Posted November 12, 2018 Share Posted November 12, 2018 I cannot over emphasize how helpful that was Quote Link to comment Share on other sites More sharing options...
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