Roosterrs Posted June 16, 2017 Share Posted June 16, 2017 My Defender is a P plate 300TDi 90 CSW. 120,000 miles. It has recently started to make a ticking noise when accelerating and today it has been more noticeable. It seems to be when it comes onto boost. I can lift the throttle and it stops and then reapply and it will start again. So I think the temperature makes it worse as some days it doesn't make the noise or is a lot less noticeable. Trawling the net, it could be head gasket, valve top retainers, exhaust gasket, but I would of thought it would make the noise all the time if it was. The vehicle seems to run OK otherwise. As it seems to be temp and boost related, could it be diesel knock? Any info gratefully received. Quote Link to comment Share on other sites More sharing options...
GW8IZR Posted June 16, 2017 Share Posted June 16, 2017 have a careful feel and listen between the back of the cylinder head and the bulkhead, from your description it may be the head gasket. HTH Quote Link to comment Share on other sites More sharing options...
Roosterrs Posted June 16, 2017 Author Share Posted June 16, 2017 It does sound as though its at the back of the bulkhead. Vacuum pump replaced a year ago. Doesn't make a noise at tickover only on boost. Can you upload a video on this site? Quote Link to comment Share on other sites More sharing options...
GW8IZR Posted June 16, 2017 Share Posted June 16, 2017 Its a fairly common failure and not the end of the world. On the ones I've done I've always been able to feel the blow by putting my hand on the back of the head/block. Even though the vac pump is only 12mths old it could be faulty, some spare parts are poor quality. Its a case of careful listening and looking, soot on the bulkhead is useful clue. HTH Quote Link to comment Share on other sites More sharing options...
SPendrey Posted June 16, 2017 Share Posted June 16, 2017 I chased a "tick" for a while, replaced the vacuum pump (had a spare from another vehicle anyway). Checked tappets etc. etc. Mine was the head gasket at the rearmost cylinder venting to atmosphere. Just stick you hand back there and you'll feel it puffing if that's the fault. Quote Link to comment Share on other sites More sharing options...
Roosterrs Posted June 17, 2017 Author Share Posted June 17, 2017 Genuine Wabco pump fitted. Put my hand at back of cylinder head and can't feel any blowing. Quote Link to comment Share on other sites More sharing options...
Roverdrive Posted June 17, 2017 Share Posted June 17, 2017 Might be as well to check around the exhaust manifold as well. If it is only audiable on boost, it might only be a small leak at this time. As said before, look for signs of soot about the back of the head and manifolds. You might be able to use a soapy water solution to find small leaks, but unless the block is cold, it will evaporate very quickly. Quote Link to comment Share on other sites More sharing options...
Snagger Posted June 18, 2017 Share Posted June 18, 2017 I too had the head gasket fail between the no.4 cylinder and aft face of the block. It only leaked on boost and working hard, and sounded like someone flicking a tightly held piece of paper. It is a very common failure. If you rev the engine while feeling around the back, you might feel it pulsing, but probably not. Given the commonness of the failure, I think you can assume yours is the same and replace the gasket; it's not hard, and should take less than a day. You'll need a torque wrench. Do it soon, as the leaking gasses quickly erode the head. Quote Link to comment Share on other sites More sharing options...
steve b Posted June 18, 2017 Share Posted June 18, 2017 It sounds like the exhaust gasket which is a relatively straightforward and cheap job , I'd do it just to check first . If not then probably the HG . cheers Steve b Quote Link to comment Share on other sites More sharing options...
Roosterrs Posted June 21, 2017 Author Share Posted June 21, 2017 It was head gasket. Put washing up liquid at back of head and started bubbling. Removed head and it is blowing out the back. Checked head flatness with parallel and feeler blade/dti. Head is very flat and can't measure a 0.001". Think it needs a very light min to clean to remove any imperfections. Quote Link to comment Share on other sites More sharing options...
GW8IZR Posted June 21, 2017 Share Posted June 21, 2017 Nice one, sorted it will be good for another 100K + miles .. Quote Link to comment Share on other sites More sharing options...
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