Geoff359 Posted November 8, 2010 Report Share Posted November 8, 2010 I've had my rebuilt engine running for about a week now, but it has developed an oil leak at the rear of the engine. My immediate thought was "crankshaft oil seal" but as I fitted the split seal type and was particularly careful about fitting it, I was a bit disappointed. The leak, however, appeared to be dripping from the L/H side of the engine (looking forward) and I knew this wasn't typical of the crank oil seal leak (seen many before!!). I have just taken the gearbox out (car's not finished inside yet - easier option than removing the engine!) and oil appears to be seeping from the plug in the oilway, with the crankshaft oil seal area being completely dry! (Hooray!! - glad I DIDN'T take the engine out). I did replace this plug on rebuild and thought I had sealed it properly with Wellseal. Since this appears not to be the case, does anyone have any tips for fitting and sealing this particular plug? Any help would be most grateful as I don't want to go through this again! Geoff Masterman Quote Link to post Share on other sites
ianc Posted November 8, 2010 Report Share Posted November 8, 2010 If you are talking of the oilway running horizontally along the left side of the engine from front to rear, you will see that it has 3 hexagon-headed, brass, plugs (set screws) to seal it. If the copper washer beneath the head of the set screw is too thin, it is possible for the thread on the set screw to bottom in the block before the washer is fully compressed. Fitting two washers will solve such a problem. How do I know? It happened to me and, because the oil went all over the place, it was difficult to trace until Carl at Revington TR finally nailed it for me. Ian Cornish Quote Link to post Share on other sites
Ade-TR4 Posted November 8, 2010 Report Share Posted November 8, 2010 Hi I would double check that it's not coming from the rear of the rocker cover: Difficult spot to see and can leak quite a bit and drain down, mimicking more awkard-to-fix leaks (ask me how I know...) Cheers Ade Quote Link to post Share on other sites
stuart Posted November 8, 2010 Report Share Posted November 8, 2010 It could also be leaking from the gallery plug screwed to the back end of the head. This should also have a copper washer fitted to it, careful sizing of the washer is needed as the hole is slightly countersunk. Stuart. Quote Link to post Share on other sites
Geoff359 Posted November 9, 2010 Author Report Share Posted November 9, 2010 Thanks for the replies, but it is definitely leaking from the rear oil gallery plug (the aluminium one behind the flywheel, as it can be seen running down the back of the block (the block was clean & dry when the engine was put in). I checked the other possibilities before I took the gearbox out (leaks from rocker cover, rear oil plug in the head, oil pressure pipe, fuel pump gasket, etc,. etc!) Some suggestions as to seal the thread PROPERLY on this ali plug would be useful. Geoff Quote Link to post Share on other sites
badshead Posted November 9, 2010 Report Share Posted November 9, 2010 Some suggestions as to seal the thread PROPERLY on this ali plug would be useful. Geoff I made a note of this stuff http://cgi.ebay.co.uk/ws/eBayISAPI.dll?ViewItem&item=200305422700&ssPageName=STRK:MEWAX:IT recently... recommended by somebody on here but can't remember who. Quote Link to post Share on other sites
stuart Posted November 9, 2010 Report Share Posted November 9, 2010 Geoff I made a note of this stuff http://cgi.ebay.co.uk/ws/eBayISAPI.dll?ViewItem&item=200305422700&ssPageName=STRK:MEWAX:IT recently... recommended by somebody on here but can't remember who. Thats good stuff and will pretty much seal anything. Basically liquid PTFE tape. Stuart. Quote Link to post Share on other sites
Geoff359 Posted November 9, 2010 Author Report Share Posted November 9, 2010 Thanks for the tips,chaps. I've just ordered some and will give it a try! Geoff Quote Link to post Share on other sites
Rob72CP Posted November 11, 2010 Report Share Posted November 11, 2010 Geoff, I replaced that plug on my engine recently during a rebuild. I think it has a 1/4" hex (i.e. Allen key) head on it. Mine was definately steel not ally, and it was VERY VERY tight originally. I think it might be a taper plug? Anyhow, the treads on mine looked perfect, so I got everything really clean, applied Wellseal (let it go off a short while) then did it up tight. So far so good and the only leak I've got after a complete rebuild is a tiny weep from the rocker cover. I wonder of your ally plug could have deteriorated / distorted over time, and if it is worth getting a steel replacement? Rimmers appear to list this as part number 118632 for £1.70 inc. VAT. I did replace the smaller plugs that go along the bottom of the oil gallery with replacements from Rimmers and the quality of these was fine. Personally I would'nt even try getting the old plug to seal given that it has already failed to seal once. Hope this helps. Rob Quote Link to post Share on other sites
Geoff359 Posted November 11, 2010 Author Report Share Posted November 11, 2010 Hi Rob, The part number you quote is actually the plug from the oilways in the crankshaft. The plug I had leak was at the end of the oil gallery, behind the flywheel (looking from the gearbox end). I'm not trying to refit the one that leaked as I had to drill it out!! Both Moss and Revington refer to this as part number 056765 and it's definitely aluminium (not tapered). I've now refitted it with appropriate thread sealer so I'm not expecting any further difficulty. Geoff Quote Link to post Share on other sites
Geoff359 Posted November 16, 2010 Author Report Share Posted November 16, 2010 Spoke too soon! The b****y thing is STILL leaking despite using the sealants recommended here. The plug is quite loose in the thread, so perhaps it needs some additional help such as Loctite 55 pipe sealing cord. Anyone used such a product on these oil gallery plugs? Or am I leading the way! It will have to get warmer before I take the gearbox out - again! Suggestions gratefully accepted (in relation to the oil gallery plugs, that is!!) Geoff Quote Link to post Share on other sites
RogerH Posted November 16, 2010 Report Share Posted November 16, 2010 Hi Geoff, when you took the old plug out did you look at the condition of the steel threads in the block. Were they in good(ish) condition? How loose is the new plug. I would have thought it shouldn't be loose at all. Could you get a new plug made with an external flange - bigger than the hole O/D so that it traps sealant (long shot) In theory the Loctite cord should work but then again so should the Welseal etc. Roger Quote Link to post Share on other sites
Geoff359 Posted November 16, 2010 Author Report Share Posted November 16, 2010 (edited) Hi Roger, The plug screws quite easily into the block and this may be due to the fact that I had to run a tap down the hole to clear the remnants of the old plug. Maybe the tap was slightly oversize! The threads in the block don't seem too bad. I did try to construct a sort of flange with a ground down bolt but there is so little clearance between the flywheel and the block, it's difficult to get any head to screw it down tightly. I have ordered some steel socket set screws which may be easier to screw into the hole, and will probably try the Loctite thread approach, unless someone has a better suggestion! Geoff Edited November 16, 2010 by Geoff359 Quote Link to post Share on other sites
stuart Posted November 16, 2010 Report Share Posted November 16, 2010 Hi Roger, The plug screws quite easily into the block and this may be due to the fact that I had to run a tap down the hole to clear the remnants of the old plug. Maybe the tap was slightly oversize! The threads in the block don't seem too bad. I did try to construct a sort of flange with a ground down bolt but there is so little clearance between the flywheel and the block, it's difficult to get any head to screw it down tightly. I have ordered some steel socket set screws which may be easier to screw into the hole, and will probably try the Loctite thread approach, unless someone has a better suggestion! Geoff You could always Helicoil it back to original size and then the correct bolt with copper washer should work Stuart. Quote Link to post Share on other sites
Geoff359 Posted November 16, 2010 Author Report Share Posted November 16, 2010 Hi Stuart, There's no room for a bolt with copper washer; that would be the ideal! This is the ali plug which goes into the back of the oil gallery (behind the flywheel). regards, Geoff Quote Link to post Share on other sites
88V8 Posted November 16, 2010 Report Share Posted November 16, 2010 ....a better suggestion It's very hard to seal a sloppy plug in a blind hole. If it were a plumbing fitting I'd wind a taper on it with PTFE tape, or use hemp + Bosswhite. Alas, I don't think either is appropriate here, but in general if you can bottom out the plug in the hole then I would assume it hasn't sealed. After the next 'fix' run the engine to the point of certainty, before refitting the gearbox. Just in case. Ivor Quote Link to post Share on other sites
Geoff359 Posted November 16, 2010 Author Report Share Posted November 16, 2010 (edited) Hi Ivor, I suppose I could do that; I'd have to fit the starter with 2 temp short bolts, but I don't see any reason why not. I've no other way of starting the engine. The Loctite 55 cord I've seen used in the USA may do the trick as it seems it can be used with oil, petrol etc. The plug as supplied is not a tapered. Regards, Geoff Edited November 16, 2010 by Geoff359 Quote Link to post Share on other sites
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