Page 1 of 2
oil leaks (im a dumb american bear with me)
Posted: Tue Feb 17, 2009 6:29 pm
by olskool
ok i know minors are suposed to leak i know this.
however ours leaking really bad to the point engine damage could result if this things drives for more 30 mins.
one large puddle seems to be coming from the front if engine the timeing chain cover area i suspect the front main seal is bad the other is the rear of engine probably a rear main i cant see evidinece of any oil above the oild pan also the oil drain plug and filter housing is leaking
this is a rebuilt engine im affraid it has sit for so long that all the seals have dried out i really dont want to pull the motor and re gasket this thing but its looking more and more like im going to have to
is this amount of oil typical or i do have bigger problems than most minors keep in mind its 1275cc supercharged motor i dont the supercharger is putting out enough boost to cause these problems and this thing has had supercharger on the 948cc with no problems so this shouldnt be the issue
like i said stupid american here just trying to figure out the weak spots in the british design patch them rather than reenginering them
Posted: Tue Feb 17, 2009 6:36 pm
by bmcecosse
No - not typical - sounds like v poor 'rebuild' !! One check -engien hot and idling - take the oil filler cap off. If there is a plume of smoke/fume - then the engine is in v poor condition and excessive crank case pressure is forcing the oil out past the front seal - and rear 'scroll' - there is no proper seal at the rear of the crank. If no fume etc - then a new sump gasket set and timing case gasket/seal is not difficult and can be fitted without taking the engine out. The drain plug and filter remedies are surely obvious !
Posted: Tue Feb 17, 2009 8:10 pm
by olskool
i have already checked the crankcase pressure just make sure the supercharger wasnt causing an issue forcing the piston rings to not seal i dont have any. I just talked with my boss and since this motor has like amybe 20 miles since the rebuild were going to pull it anyway and regasket the whole motor will aslo give me a chance to assess the rebuild quailty i didnt rebuild the motor (wish i would have)
we are going ot convert to a spin on filter rather than this canister style that will solve the problem permantley and new oil pan will be ordered as this one has dent right at the drain plug which is most likley the casue of it leaking
i really didnt want to go this far but at least it gives me the chance to set the motor up properly
this project has literally been one step forward two steps backward i just want it out the shop and done so i can get to work on the parts car and TR6 i got sitting next to it.
Posted: Tue Feb 17, 2009 8:11 pm
by rv8
could be the oil thrower incorrectly fitted and has cut a hole in the timing case cover?
Posted: Tue Feb 17, 2009 8:21 pm
by olskool
i havent seen a hole in timing cover but i will deffeintaley check that
Posted: Tue Feb 17, 2009 9:56 pm
by moggyminor16
do check that i was doing 25 miles and about 3 ltrs of oil a day untill i used filler to plug it untill the 1275 was read to go in but did not last went bang lol
Posted: Tue Feb 17, 2009 10:27 pm
by bmcecosse
Could very well be crankcase pressure from the blower - make sure the breathers are open and plentiful - - and one of them needs to be connected to the inlet system BEFORE the blower obviously - to draw fumes away into the engine. If you don't do this - it WILL leak oil at every possible orifice !
Posted: Tue Feb 17, 2009 10:43 pm
by mike.perry
Check the crankshaft pulley O ring in the front of the timing chain cover.
Also when you have the engine out check the scroll on the back of the crankshaft. This is designed to throw the oil back into the engine and if it is worn then oil will get past it.
Posted: Tue Feb 17, 2009 10:56 pm
by Kevin
Unlikely I know but I suppose the 1275 engine had its own timing cover used and not one from another engine as this can cause strange leaks.
Posted: Tue Feb 17, 2009 11:02 pm
by bmcecosse
Because it has no breather!
Not understanding m-p's O ring comment ?? It's a proper lip seal in there - not an O ring! Good point about possible missing oil thrower - but I do believe it's most likely to be a pressure problem, especially in view of the blower!
Oil leak
Posted: Wed Feb 18, 2009 6:37 am
by Declan_Burns
Try running the engine with the car over a pit, having cleaned off all the oil and grud beforehand. This will help to locate the actual source of your oil leak(s). If you have to replace the sump gaskets, I would recommend using the spridget 1275cc synthetic rubber seals instead of the cork seals. This worked for me as I tried cork several times without success. Thoroughly clean and degrease all surfaces and use high temperature silicon allround allowing it to cure properly before starting the engine. Check also the tappet chest seals. Again could be cork but there are modern neoprene seals available. Otherwise as above.
Hope it helps.
Declan
(DEC 1964H formerly HMP 960B)
Posted: Wed Feb 18, 2009 7:41 am
by bmcecosse
I agree with the rubber seals - but you shouldn't need silicone - or even 'gasket cement' !
Oil leak
Posted: Wed Feb 18, 2009 7:57 am
by Declan_Burns
On mine the leak was so persistant and I was so fed up and didn't want to take any chances for the sake of the cost of the silicon. It works perfectly but I agree, it may very well have worked without it. On the other hand, I have no intention of removing it again to find out! What is sealed is sealed and I'm relieved-and the neighbours too!
Declan
(DEC 1964H formerly HMP 960B)
Posted: Wed Feb 18, 2009 9:32 am
by mike.perry
'O' ring was probably not a good description of the timing cover oil seal. I had one go on a trip back from mid Wales to Hampshire many years ago and it took a couple of gallon cans of oil to get the van home.
Posted: Wed Feb 18, 2009 10:26 am
by dunketh
The front seal is easy to change, almost a joy compared to most jobs.
The rear doesnt really have one. Not having changed the 'thrower' I don't know about this. Mine used to weep a bit from the back but not enough to worry about and more so when you thrashed it.

Posted: Wed Feb 18, 2009 3:51 pm
by olskool
thanks for the info i got alot things to check thanks for the info on rubber seals i really didnt want cork. im pretty sure when i pull it apart im going to see things not done right its been the story of this car since i started on it
Posted: Thu Feb 19, 2009 9:23 am
by Pyoor_Kate
Well, it does sound like someone's made a hash of putting the seals and/or gaskets in. Hell, even when I cut the (cork) seal on the sump of my 1275 (ital) slightly short* (a couple of mm) it didn't leak anywhere near that badly...
* We'll call that a learning experience, shall we?
Re: Oil leak
Posted: Thu Feb 19, 2009 4:55 pm
by Kevin
Declan_Burns wrote: Check also the tappet chest seals. Again could be cork but there are modern neoprene seals available. Hope it helps.
Declan
(DEC 1964H formerly HMP 960B)
And where are the tappet chest seals on a 1275 engine ?
Oil leaks
Posted: Thu Feb 19, 2009 5:51 pm
by Declan_Burns
Sorry,
I was going back in memory on all the oil leaks I had to cope with since I started on my 1098cc. Yes you are right and our American friend will have one source less to deal with. I wasn't quite so lucky.
Declan
Posted: Thu Feb 19, 2009 8:32 pm
by olskool
ok well i in fact do have some presuure in the crank case i tested all the cylinders they were all the same 125psi or just a little less than 9 bar
is this low or high