craig_95_ Posted March 21, 2015 Share Posted March 21, 2015 iv recently brought a 300tdi discovery and the engine has a very loud knock and when you hold your foot down on the accelerator it will splutter for about 15 seconds then rev up properly until you take your foot off and try to rev it again it will then do the same again. Quote Link to comment Share on other sites More sharing options...
KenM Posted March 21, 2015 Share Posted March 21, 2015 I would first check the timing is spot on, sounds lit sounds like sticking injector(s) whilst ticking over crack of the injector pipes onto the injectors 1 at a time you should notice which injector is causing the problem, good luck Quote Link to comment Share on other sites More sharing options...
Team Idris Posted March 21, 2015 Share Posted March 21, 2015 I'd say injector, but not on all four pots. Pump timing maybe? Quote Link to comment Share on other sites More sharing options...
Nigelw Posted March 21, 2015 Share Posted March 21, 2015 Have you done the basic servicing on it yet, fuel filter, sedimentor, oil and oil filter? Does the lift pump operate as it should? Any idea where on the engine the knock is coming from? Quote Link to comment Share on other sites More sharing options...
steve b Posted March 21, 2015 Share Posted March 21, 2015 My 50p is on blown headgasket letting water into a bore . Remove all 4 injectors or all 4 heater plugs and crank over with inj pump solenoid disconnected . Any water will get blown out as mist or if it's really bad , liquid . The knock would be the engine hydraulically locking from the water . Was there a lot of white smoke from exhaust when you revved it with the misfire ? I wouldn't run it again until you've done the test above for water as I have had one bend a con-rod from a HG water leak .... cheers Steveb Quote Link to comment Share on other sites More sharing options...
Boydie Posted March 22, 2015 Share Posted March 22, 2015 Craig, blown head gaskets are the bane of the 300Tdi engine. I'd advise a total top end service, change the head gasket, personally I'd advise you use a composite rather than a metal one, there are three selections of thickness, ensure you choose the correct one by the holes stamped on the RH edge. Have the head checked that it isn't warped or cracked, this will require getting it pressure tested for cracking and a good quality straight edge for warping.. Next see if the timing belt drive has been upgraded, if not fit the latest crank pulley/cogwheel and ensure that the Fuel Injection Pump is correctly timed. Give the Disco a total service, new oil, change all the filters etc. and you should not have any further problems unless you have a dud injector, - you can have these tested possibly at the same place that you have the head pressure tested. Oh and welcome to the forum -- you will be able to search and find all the info you need here on this site, if in doubt, ask. Obtain a RAVE CD -- it have the complete service manual on it. Quote Link to comment Share on other sites More sharing options...
craig_95_ Posted March 24, 2015 Author Share Posted March 24, 2015 Sorry iv not got back to you but the knock sounds like it's coming from the camshaft. The engine has had new head gasket, head has been skimmed, new fuel filter tim8ng has been done and checked the injectors they all working fine but it still won't rev up and there is lots of white smoke smells like diesel and there is the loud knocking noise that is loud3nt by the camshaft Quote Link to comment Share on other sites More sharing options...
craig_95_ Posted March 24, 2015 Author Share Posted March 24, 2015 Sorry iv not got back to you but the knock sounds like it's coming from the camshaft. The engine has had new head gasket, head has been skimmed, new fuel filter tim8ng has been done and checked the injectors they all working fine but it still won't rev up and there is lots of white smoke smells like diesel and there is the loud knocking noise that is loud3nt by the camshaft Quote Link to comment Share on other sites More sharing options...
craig_95_ Posted March 24, 2015 Author Share Posted March 24, 2015 Sorry iv not got back to you but the knock sounds like it's coming from the camshaft. The engine has had new head gasket, head has been skimmed, new fuel filter tim8ng has been done and checked the injectors they all working fine but it still won't rev up and there is lots of white smoke smells like diesel and there is the loud knocking noise that is loud3nt by the camshaft Quote Link to comment Share on other sites More sharing options...
BogMonster Posted March 25, 2015 Share Posted March 25, 2015 http://forums.lr4x4.com/index.php?showtopic=22463 Quote Link to comment Share on other sites More sharing options...
Boydie Posted March 25, 2015 Share Posted March 25, 2015 Craig, 9 times out of 10 white smoke = water = blown or leaking head gasket. If, as you say the head has been skimmed and the gasket is new I'd lay odds on it not being taken up correctly. You will need a GOOD torque wrench AND a dial gauge. I'd also bet that one of the multi-plate metal gaskets have been used. While these are a good gasket I still believe that the composite gaskets are better, but buy a reputable one - NOT one in a BLUE container (BR---RT). Even when I re-built my engine the original camshaft bearings were still within their original tolerance so I don't think worn camshaft bearings are the issue. The knock could however be that the fuel lift pump, or the vacuum pump have been incorrectly installed, for both to site correctly on the camshaft lobes the engine needs to be at TDC on No.1 piston, again, read the RAVE manual Quote Link to comment Share on other sites More sharing options...
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