37 replies to this topic

[emile]

Hi guys, 

 

Sorry in advance, i´m just getting started working on minis and my english car vocabulary isn´t the best.

My problem is the following: my 1991 Mini Twinings is leaking oil and it´s leaking from the "fan-side" of the motor.

I took it on the lift and saw that there was oil coming from where the stub-axle meets the diff, and i replaced the seal.

I also replaced the seals from the gear selector shaft and the petrol pump.

The last thing i did was replacing the gasket of the timing chain cover and the seal where the crankshaft pulley sticks thru the cover. I was very careful when tightening the cover-screws so i don´t think i bent it when reassembling.

It´s still leaking oil (maybe 2 Tablespoons) everytime i park it in the garage. But after a while when it´s parked, the leakage stops.

 

Does anybody know what else it could be or what i should be looking for?

 

Would be very thankful for help!

 

1991 Mini Twinings, 998cc A-Plus Engine

Edited by emile, 05 December 2023 - 02:09 PM.

[Bobbins]

It's highly likely the leak is coming from the engine-gearbox half moon oil seal: https://www.minispar...px|Back to shop

[Stevie W]

Could also be one of the tappet chest covers leaking oil and the oil is running down the back of the engine block and onto the gearbox casing. Same could be true for the rocker cover gasket.

 

Cheers, Steve.

[nicklouse]

Stop guessing and get some UV oil leak test fluid. That and a “black” light and you will know exactly where it is starting from

[weef]

Did you centre the crankshaft seal before you tightened the timing cover bolts ?.

The procedure is to fit the cover leaving the bolts loose, fit the crankshaft pulley and centre it on the seal, then leaving the pulley in place tighten the cover bolts.

[Royalasaforce]

I had a similar issue and turned out that the timing chain cover itself had a pin hole allowing oil out

[emile]

Thanks everyone for the quick help!

 

@Bobbins Okay, where exactly would the half moon seal be located? As i said, i never worked on minis before... but that does sound like i would have to take the engine completely out?

 

@Stevie W I don´t think it´s the Rocker cover gasket, as it´s losing oil further down on the block and more on the side, the top is basicly dry.

 

@Nicklouse i will probably do that if i don´t find the leak in the next days, was just hoping i could identify it without UV fluid.

 

@Weef Yes, i fitted the crankshaft pulley and slowly tightened down every screw i could reach with the pulley in place, afterwards i had to take it off to tighten the last screws on the bottom.

[emile]

I had a similar issue and turned out that the timing chain cover itself had a pin hole allowing oil out

 

You´re right, would´ve been smart to check that first instead of instantly refitting it. 

I hope that i ´ll have the time tomorrow to throw my mini back on the lift and have a better look. 

Will keep you updated

[Bobbins]

 

@Bobbins Okay, where exactly would the half moon seal be located? As i said, i never worked on minis before... but that does sound like i would have to take the engine completely out?

 

 

Yes it's engine out and split from the gearbox to replace it .... check all the other suggestions first!

[nicklouse]

 

 

@Bobbins Okay, where exactly would the half moon seal be located? As i said, i never worked on minis before... but that does sound like i would have to take the engine completely out?

 

 

Yes it's engine out and split from the gearbox to replace it .... check all the other suggestions first!

 

Not 100% correct as there is a ridgid half moon seal that does not need the gearbox splitting so can be done in car.

[Designer]

Minispares sells it, part number CAM6548

 

 

Not sure if you have to remove the timing gear front plate to be able to remove the old seal and push the new hard seal in.

[Bobbins]

 

 

 

@Bobbins Okay, where exactly would the half moon seal be located? As i said, i never worked on minis before... but that does sound like i would have to take the engine completely out?

 

 

Yes it's engine out and split from the gearbox to replace it .... check all the other suggestions first!

 

Not 100% correct as there is a ridgid half moon seal that does not need the gearbox splitting so can be done in car.

 

 

Good point.

[bpirie1000]

Certainly sounds like something that may only be found when the engine is hot (due to the leak appearing to stop after parked, i.e. cooled down)

My money is on timming cover leak.

What is the history, miles?

On the plus side the oil on the subframe drops it rusting away....

Could you get some wire brush action in there and see after a run round the block?

[emile]

My money is on timming cover leak.

What is the history, miles?

 

It was almost daily driven from 1992 to 2000, and from 2000 - 2010 it was driven very rarely and only in the summer. 2010- last year it was hidden in the garage. As of now, it has around 115.000 km (70ish thousand miles).

Last year i got a hold of the car and had a lot of body- and framework done because the passenger floorboard was basically looking like the flintstone mobile. 

Motor wise, i only did the usual stuff: new spark plugs, air filter, liquids and a new water pump ... and in the last few weeks i started renewing most of the seals and gaskets.

I also thought the aparrent leak would be the timing cover, but i (very carefully and like described in my Haynes) changed the seal and gasket last sunday and it´s still leaking oil somewhere in that region...

[emile]

Could you get some wire brush action in there and see after a run round the block?

I´ll try to get to it this evening or tomorrow, maybe i´ll find some hints