monkie Posted October 3, 2021 Share Posted October 3, 2021 I rebuilt a defender 200Tdi (I'll detail what I did and didn't do further down). All the parts I used were supplied by Turners, so nothing from a blue box. Quality mineral engine oil used at correct spec and quantity. Engine in, all the necessaries conected up so I fired it up. It started straight away and sounded lovely - sweet as a nut, no smoke other than the usual puff as it starts. I was extrememly pleased. Then the next day when I started and ran the engine to get it to temperature, I noticed the oil presure starting to drop quite quickly (I have a Stack guage fitted). I quicky pulled the oil feed to the turbo off hopign for it to be squirting out - no oil. I very quickly undid the oil pressure sender and oil just trickled out, I would expect it to gush out with it at idle. I then immediately cut the power to the engine to stop it running. I initially took the rocker cover off and the rocker shaft looked fine. I took the engine out in just 90 minutes (its amazing how quickly you can do this when the exact location of all the nuts, bolts and pipes are fresh in your mind), got it on a stand flipped upside down and removed the sump and ladder frame. There was some slithers of copper metal in the sump (tell tale sign of bearing material). This is what I have found so far: The oil pump seemed fine, no cracks, the pick up pipe was okay, the oil pump had oil in it as I removed it. The drive shaft to the oil pump turned when the engine was turned over by hand. I pulled the main bearing caps off and the white metal was a little scuffed but nothing worrying, the crank journals were fine. I pulled the big end caps from the con rods. 1, 3 and 4 were a little scuffed but fine. Crank okay. Bearing on piston 2 was down to the copper and had some slithers off it (explains the metal in the sump). Crank looks okay. This is as far as I have got with the dissmantling. I'm now starting to think that maybe the dreaded cam bearing has moved? This is what I did on the rebuild: Engine completely stripped down to bear block Degreased and cleaned all parts and inspected/measured them for wear New main bearing shells New big end shells New thrust washers (crank end-float was in spec so used standard size) New piston rings (honed the bores) Rebuilt the oil pump with the kit from Turners including new pressure releif valve New valve springs New timing belt New top and bottom end gaskets/seals New injector nozzles I did not renew the cam shaft or the cambearings but did use a new cam thrust washer (standard), all was in spec. As I assembled the engine I used an assembly lubricant on all bearing surfaces to ensure good lubrication on start up. I'm at a loss so far as to the cause. I'll keep on going with the strip down until I find the smoking gun. Anyone have any ideas? 2 Quote Link to comment Share on other sites More sharing options...
cackshifter Posted October 3, 2021 Share Posted October 3, 2021 Could it be the relief valve sticking? If it didn't get warm the first time you ran it, maybe it relieved pressure and maybe it stuck . The second time, the oil was cold and quite thick, pressure good till it started to warm? Quote Link to comment Share on other sites More sharing options...
western Posted October 3, 2021 Share Posted October 3, 2021 Pull the cam out & the rear side cover above lift pump that will give access to look at the No 4 cam bearing to see if it has rotated or moved back to cover the oil feed hole. Could be a jammed relief valve but unlikely as its new. Quote Link to comment Share on other sites More sharing options...
monkie Posted October 3, 2021 Author Share Posted October 3, 2021 The thing I don't understand and I'm wondering if it is a clue is the damage done to big end bearing on number 2 where the damage on the rest is minimal. Wondering if the oil ways in the crank are blocked, but why would that result in a sudden drop off in pressure? Quote Link to comment Share on other sites More sharing options...
steve b Posted October 3, 2021 Share Posted October 3, 2021 Plastigage No2 big end with new shells ? It could be an issue with No2 rod big end . Was it fitted the same way round as the other three ( tab location )? Steve Quote Link to comment Share on other sites More sharing options...
monkie Posted October 3, 2021 Author Share Posted October 3, 2021 4 minutes ago, steve b said: Plastigage No2 big end with new shells ? It could be an issue with No2 rod big end . Was it fitted the same way round as the other three ( tab location )? Steve Could be. I'll recheck, but the con rods were all checked, but the thing I didn't do (now thinking I should) is use a Plastigage on the bearings. Let's assume there is something wrong with that big end, how could it stop all pressure? Bits of bearing clogging up the pump? Before I go further with the engine, I will strip the pump. I'll also put some photos up in the week when I get time. Let's look on the brightside. Hopefully when the problem is found, put right and the engine back in: I will be able to find diesel freely to fill the tank!! Quote Link to comment Share on other sites More sharing options...
Bowie69 Posted October 3, 2021 Share Posted October 3, 2021 A failed bearing as you describe would start oil pressure dropping as you describe. Suspect your cam is fine, something went amiss with that big end either during assembly or a compromised bearing. Quote Link to comment Share on other sites More sharing options...
monkie Posted October 3, 2021 Author Share Posted October 3, 2021 Each possibility raises new questions for me that I'm struggling to answer: Would a failed big end bearing cause oil pressure to drop to almost nothing at the sender? How could a big end bearing be assembled incorrectly or be dodgy to cause failure in such a short time under no load? But then again, if it isn't a dodgy or incorrectly installed bearing, why would just 1 fail?  EDIT: the bearings were supplied by Turners, I think they were King brand which I understand to be a reputable make. Quote Link to comment Share on other sites More sharing options...
Bowie69 Posted October 3, 2021 Share Posted October 3, 2021 6 minutes ago, monkie said: Would a failed big end bearing cause oil pressure to drop to almost nothing at the sender? Quite possible. Measure your clearances and see what's what... Quote Link to comment Share on other sites More sharing options...
monkie Posted October 3, 2021 Author Share Posted October 3, 2021 I think the strip down of the oil pump will be interesting. I'll try and do it this evening and post some pictures of what I find. If something has gone wrong with oil pump it would explain the lack of pressure at the sender. Quote Link to comment Share on other sites More sharing options...
Bowie69 Posted October 3, 2021 Share Posted October 3, 2021 Pressure is pressure, doesn't matter where the gap is that is letting oil out, it will drop pressure right back to the pump/sender. 1 Quote Link to comment Share on other sites More sharing options...
monkie Posted October 3, 2021 Author Share Posted October 3, 2021 3 minutes ago, Bowie69 said: Pressure is pressure, doesn't matter where the gap is that is letting oil out, it will drop pressure right back to the pump/sender. Good point. Mustn't forget pumps make flow not pressure. Quote Link to comment Share on other sites More sharing options...
cackshifter Posted October 3, 2021 Share Posted October 3, 2021 As you were getting no oil to the turbo it must have been a fair old problem. Also fingers crossed the turbo is ok, the oil to that is fairly crucial Quote Link to comment Share on other sites More sharing options...
monkie Posted October 3, 2021 Author Share Posted October 3, 2021 I didn't rev it and the turbo feels okay in terms of rotating freely and minimal end float. Here's some pics of the bearings. Big end 1, main bearing 2, big end 2 from left to right.  Quote Link to comment Share on other sites More sharing options...
steve b Posted October 3, 2021 Share Posted October 3, 2021 The No2 big end journal looks nasty . Is that scoring or burnt oil ? I would be pulling that down to bare block for cleaning everything and in the process the smoking gun will show itself Steve Quote Link to comment Share on other sites More sharing options...
monkie Posted October 3, 2021 Author Share Posted October 3, 2021 6 minutes ago, steve b said: The No2 big end journal looks nasty . Is that scoring or burnt oil ? I would be pulling that down to bare block for cleaning everything and in the process the smoking gun will show itself Steve Absolutely. The crank looks worse on those pictures than in real life, but I shall take it to my local engineering shop to have them do the necessary. 1 Quote Link to comment Share on other sites More sharing options...
monkie Posted October 3, 2021 Author Share Posted October 3, 2021 Last pics of the night. I took the oil pump apart and can rule out oil pump failure. Relief valve was not stuck. There is some scoring on the top face of the housing and the rotors the confirm it was indeed turning. No debris in the pump, and no marks on the rotors.  Quote Link to comment Share on other sites More sharing options...
western Posted October 3, 2021 Share Posted October 3, 2021 I think it would be a good move to remove the crank & have it reworked, 10 thou undersize on mains & big ends is the minimum you can go, that should remove any/all scores/marks, with new .010 bearing shells, that's what my crank got. 1 Quote Link to comment Share on other sites More sharing options...
monkie Posted October 3, 2021 Author Share Posted October 3, 2021 When the realisation hit that I had no choice but to remove the engine and strip it down again when I was so close to testing out a nice fresh engine and gearbox, my heart totally sank and was daunted. I really appreciate everyone's input and helpful thoughts. It's made me take a pragmatice approach and find the fault and build it back up fresh. Thanks guys. 3 Quote Link to comment Share on other sites More sharing options...
steve b Posted October 3, 2021 Share Posted October 3, 2021 It'll work out , and the plus is we will all learn something from it . I'm definitely intrigued , you seemed to have covered all the bases Steve 3 Quote Link to comment Share on other sites More sharing options...
Popular Post cackshifter Posted October 3, 2021 Popular Post Share Posted October 3, 2021 I think irrespective of what is wrong, you deserve huge sympathy for a disappointing start of a refreshed engine. It can be disheartening, but you seem to have risen above that, so crack on, you will win. 5 Quote Link to comment Share on other sites More sharing options...
reb78 Posted October 3, 2021 Share Posted October 3, 2021 Hear hear^^^. I feel for you Phil. You will get a good engine at the end of it though. 1 Quote Link to comment Share on other sites More sharing options...
Bowie69 Posted October 3, 2021 Share Posted October 3, 2021 That #2 bearing, have you had the shell out of the cap? Looks like it isn't seated in the notch, it is deformed and slightly tweaked over -this would close up your clearances and do exactly what you have seen (one smoked bearing). I guess what I am saying is it possible it was installed like that? 1 Quote Link to comment Share on other sites More sharing options...
monkie Posted October 3, 2021 Author Share Posted October 3, 2021 Yes, it's been out. I remove the shells to see them all round. I'm not ruling out any silly mistake on my part. But that is a posed photo with the shell in loose just popped back on the cap to show you all. I'm wondering if this is down to a silly mistake on my part or cutting of corners: I should have got the crank looked at by an engineering shop and I definitely should have used Plastigage with the new shells. When I rebuilt a 19J I took the crank to them and they said it looked worse than it really was and I could have got away with new shells. I think that comment perhaps filled me with false confidence this time round? 1 1 Quote Link to comment Share on other sites More sharing options...
Nonimouse Posted October 4, 2021 Share Posted October 4, 2021 Just for future reference, when a cam bearing creeps, you get a specific type of pressure loss - pressure can be raised to normal cold running pressure, as you build up the revs, but it won't stay there Pump failure is just a total loss of pressure Turbo seals is pressure but low Hope this helps By the way, if you are stripping the lump down. check those cam bearings and if they are slightly loose, use locktite to hold them in place 2 1 Quote Link to comment Share on other sites More sharing options...
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