MG Metro Turbo distributor oil leak
Turbo Mini Forums

Hi all,

my car has developed a mystery oil leak ?

I have found oil on the oilcooler & innerside of the front panel (only after long & fast motorway driving)

so yesterday I cleaned it all off, and wrapped the oil pressure gauge pipe in a clean White cloth.

Then took it for a test drive.



It still leaks oil , and it wasnt the pipe for the oil pressure gauge.

That was still clean when I came back, but there were oil on top of the oilcooler again.



I took the grill off, as I also could see oil on the underside of the distributor.



So either its oilspray from a small crack in the top of my (brand new) oilcooler



Or its oil dripping from the distributor ???

I tried to suck on the thin hose that goes to the intake manifold ( ignition advance ) and it sounded ”squishy” (no leak) like there were oil, on the other side of the rubber diaphram ?.
Didnt do anything to it before fitting it, it just sat in a box for 8 or 9 years.
Maybe some seal around the axle has gone hard/cracked ? anyone experienced this ?


Next question = have anyone repaird one of these MG distributors before ?

It looks like this = http://www.dummett.net/ime/website/ime/ime...zy/dizzy_01.jpg

When I remove the cap, I only see a alloy plate, that seal off all the electronics underneath.




Jens Christian

Edited by JC T ONE on 26th Sep, 2013.

yes the seals perished you can get new ones.

On the distubutors I dismantled (to make phase sensors for my fuel injection system) there were/are no seals on the shaft. Mine were earlier points type (but still A+) but I doubt they changed that part of the design when they went electronic (I've had an electronic one apart and don't remember that part being different but I only have photos of the points type shaft).
The way the bearing bushes are lubricated and oil kept out of the dizzy body is by a spiral groove (a scroll) machined in the shaft where it runs in the lower bush forcing the oil back down to the sump end (like an archimedes screw). The main cause of it letting oil past is if there is severe wear in the bushes. Is there any significant side to side play in the shaft if you try to push it side to side where the rotor arm fits ?

Also check very carefully where the oil is coming from - if you look at the photo you have attached you can see two holes in the bottom of the dizzy (some only have one) which is where the oil will come out if it is passing up the shaft - but also note in your picture, there is an O ring lower down around the part of the dizzy that fits into the block - this is what usually leaks and the oil will appear at the flange above that (the flange that the clamp yoke sits on).

If it is that O ring (quite likely IMO) they are very hard to get hold of as a Mini (or Metro) part - I have never seen one in an engine gasket set and never seen one advertised by the usual Mini supppliers. I measured one and bought a bag of 20 (minimum order quantity) when I was buying all my O rings for the fuel injection system from an industrial supplier.

As for dismantling the dizzy, take the module off the side first (the electrical connections "plug" in so once the screws are out the module can be "unplugged") and the plate for the internal "electronics" (actually just rotating vanes, magnets and a hall switch) is held in with a couple of screws. The vacuum advance unit also needs unhooking from the plate and removing then, on the drive dog at the bottom, there is a very small roll pin that goes through the two drive lugs (can't see it in your photos because the drive lugs are side to side in the picture, you need to look at them end on). You need a very small pin punch to drive it out but mark the shaft and drive dog first - they are offset so the dizzy can't go in 180 degrees out and the roll pin is off centre so the drive dog can only go on the shaft in one position and if you try to put the pin back in later with the dog 180 out it will jam and break. Once the roll pin is out, the drive dog will come off (it might be a bit tight as the roll pin hole tends to burr over when the pin is fitted) then the shaft, advance weights etc simply pulls out of the dizzy body.

As for spares, apart from the electronic module (eBay or any decent Auto factors) I don't know. I would change the O ring where the body fits in the block before pulling it apart or, if it is wear in the shaft/bushes, just get a secondhand one. Just my opinion though.

Schrödinger's cat - so which one am I ???

What about the dipstick? does the engine breathe heavy? or is the breather system adequate or blocked? Its common from time to time for big bore engines to eject oil out through the dipstick tube which is why you see a spring from the dizzy clamp to the top of the dipstick from time to time.

Hi all,

thanks for your helpfull & informative replies.

It IS the distributor that leaks oil .

There is no play in the shaft, so maybe the "spiral" that should push the oil back, is dirty/filled up with sod .

I remember that the inside of engine & gearbox, were covered with loads of Black sod.
The stuff were really burned onto the surfaces, just like in a combustion chamber.

Edited by JC T ONE on 28th Sep, 2013.

Schrödinger's cat - so which one am I ???