chrisbladen Posted October 29, 2019 Report Share Posted October 29, 2019 Hi, just wandering if anyone has ever experienced a rear engine plate gasket leaking? I have a 1500 spitfire and basically what iv done is removed the gearbox, taken the engine out and while it was out iv degreased it and painted it. Today I noticed a slight leak on the floor which baffled me as the oil has been drained for a few weeks and I fully removed the sump to clean and paint it so it is defiantly empty of oil. it seems to be running down the back of the rear engine plate where it meets the block, (I have attached 2 pics) I'm thinking it could be one of a few things... 1) when I have pressure washed it it has worked into the gap between the rear engine plate and block and it is just oily water that is running down?? (not sure it would still be running now though as its been a week since I washed it) 2) the rear plate gasket needs replacing (however I never noticed an oil leak while I was driving the car???) 3) behind the driveshaft there seems to be a gap (see pic), which looking at the rimmers catalogue, is for a plug. having googled it, it looks like a grub screw type plug, so I was thinking maybe this is missing/ damaged...but then again I surely would have noticed oil in the bell housing when I removed it if this was the case? my concern is that if there is an issue i would rather sort it now before I reassemble the gearbox and drop it back in the car. is it much work to remove the flywheel and remove the rear plate to change the gasket, if not then possibly worth doing this anyway? any advice would be gratefully received, thanks Link to comment Share on other sites More sharing options...
Steve P Posted October 29, 2019 Report Share Posted October 29, 2019 Is it oil? in the second pic that looks like the instant gasket type stuff some people use. The recess in the back is the end of the oil gallery and should have a tapered grub screw in it,if this was missing you would lose all the oil in a short time. Leaking?,possibly but i wouldn`t have thought it started without being disturbed. Easy to get the flywheel off and check while it`s out of the car. Steve Link to comment Share on other sites More sharing options...
chrisbladen Posted October 29, 2019 Author Report Share Posted October 29, 2019 Hi steve...yes its definatly oil there was a small puddle in the floor and a run of it on the rear plate...seems a bit thinner than usual though which is why im thinking maybe its mixed with water wen iv pressure washed it and its just pily water thats running down? I did think that would be a grub screw so thats cleared that up thanks. Im guessing its just a case of remove clutch from flywheel....flywheel from rear plate and then remove the rear plate to replace the gasket? Is it worth replacing the crankshaft oil seal while im on? Thanks Link to comment Share on other sites More sharing options...
Pete Lewis Posted October 29, 2019 Report Share Posted October 29, 2019 There is no full back plate gasket , there is nothing to seal the oil seal housing for the crank is the only gasket at the rear plate There is a welch plug which blanks the cam rear journal bore , these can leak To be sure you do need to whilst engine is out is whip the clutch and fly wheel off as suggested It can be a residue of oil built up by spilt over the rocker cover over the years and youve disturbed it with a wash down Pete Link to comment Share on other sites More sharing options...
JohnD Posted October 29, 2019 Report Share Posted October 29, 2019 Is that hole in the plate to give you access to the allen plug in the back of the main oilway in the block? It is on a six. Pete is, of course, correct, but I'd add as a source of an oil leak, the rear crank oil seal. This sits in its own housing, bolted to the block through a gasket. The seal is more likely to be the leak than the gasket - the seal rubber can wear a groove in the crank surface, making for a poor the seal. Best cure is a SpeediSleeve. John Link to comment Share on other sites More sharing options...
chrisbladen Posted October 29, 2019 Author Report Share Posted October 29, 2019 1 hour ago, JohnD said: Pete is, of course, correct, but I'd add as a source of an oil leak, the rear crank oil seal. This sits in its own housing, bolted to the block through a gasket. The seal is more likely to be the leak than the gasket - the seal rubber can wear a groove in the crank surface, making for a poor the seal. Best cure is a SpeediSleeve. John Thanks john. Would that oil seal give a leak where mine appears to be leaking? On the rear of the plate where it meets the block? You can see the moist patch on the 2nd pic....this is the only place where it appears to be wet Link to comment Share on other sites More sharing options...
Pete Lewis Posted October 29, 2019 Report Share Posted October 29, 2019 your leak looks a bit high to be crank more likely cam zone or spillage, Afraid there's no point in us all throwing a guess the only solution is ' look see' pete Link to comment Share on other sites More sharing options...
chrisbladen Posted October 30, 2019 Author Report Share Posted October 30, 2019 Thanks for the advice guys. The thing im finding most confusing is the fact that theres actually no oil in there. Its been drained for at least 2 weeks which is why its making me think is it oily water that is just finding its way down from wen i washed it. But that was over a week ago aswell??? Its a bit of a strange one 2 b honest. Link to comment Share on other sites More sharing options...
JohnD Posted October 30, 2019 Report Share Posted October 30, 2019 Not strange at all, what is strange is that you cannot accept that pressure washing from the outside will clean the inside. Oil on inside gets outside. No outside oil just makes room for inside oil. If inside oil gets outside that's just an outsizing of accumulated insider oil. It's insidious. Do like Guru Pete says, Little Grasshopper. Get that flywheel and rear plate off and have a look! John Link to comment Share on other sites More sharing options...
Pete Lewis Posted October 30, 2019 Report Share Posted October 30, 2019 And stick your finger in it is it just oil, is it black , is it a mix of oil degreaser and water , as the engine is out its only a few bolts to solve your own mystery if you dont look see you will never satisfy your curiosity .....we cant Time to bite the bullet ... get it apart !!! Clean it up and re assemble Pete Link to comment Share on other sites More sharing options...
chrisbladen Posted October 30, 2019 Author Report Share Posted October 30, 2019 1 hour ago, JohnD said: Not strange at all, what is strange is that you cannot accept that pressure washing from the outside will clean the inside. Oil on inside gets outside. No outside oil just makes room for inside oil. If inside oil gets outside that's just an outsizing of accumulated insider oil. It's insidious. Do like Guru Pete says, Little Grasshopper. Get that flywheel and rear plate off and have a look! John It is strange given that i washed it probably 10 days ago and its been in a warm room since? And only showed as a leak now? Thanks for the guys giving genuine advice Link to comment Share on other sites More sharing options...
JohnD Posted October 30, 2019 Report Share Posted October 30, 2019 Yeah, verily, for there is no end to the contrariness of the unattended engine. John Link to comment Share on other sites More sharing options...
Ben Caswell Posted October 30, 2019 Report Share Posted October 30, 2019 There was possibly a small amount of oil laying in the cavity between the block and back plate pressure washing the engine has possibly pushed and amount of water into the cavity, as oil floats on water it has raised the oil up higher where it has now escaped . The oil must have come from somewhere so as Pete says it needs investigating. Link to comment Share on other sites More sharing options...
Peter Truman Posted October 30, 2019 Report Share Posted October 30, 2019 How to get all the oil out of that engine! Squeeze the car! Taken from the Joke section of the Forum, there are some good jokes there by all the old Stalwarts! A good way to spend time on a very hot day when the AC has broken, small lizard shorted out the circuit boards! Expensive Peter T Link to comment Share on other sites More sharing options...
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