14 replies to this topic

[ksj]

My 1979 Mini suddenly developed an oil leak on the backside of the engine. The car is a RHD, and the oil is leaking somewhere above the exhaust pipe. It started out leaking slowly and, ten miles later, is leaking about a quart a minute.
I've laid under the car and looked from all angles above and cannot see the leak.
Any advice is greatly appreciated.
Joe
Colorado, USA

[yousmeg]

Above which part of the exhaust pipe?

[ksj]

It is dripping down onto the pipe where it curves to go under the car. This is right under the firewall. I hope this makes sense.

[yousmeg]

hmmmmmmm what size engine have you got? seems a strange place to have an oil leak...

[Simon_P]

Could it be the gear selector seal with the oil blowing backwards? Best to get it on a ramp (one you can walk under ideally), and take a look.

[Boycie]

May be one of the rubber seals on the 'tappet chest' covers if it has them (eg 850, 998, 1098cc). Another possibility is the fuel pump gasket where it bolts to the block.

[yousmeg]

May be one of the rubber seals on the 'tappet chest' covers if it has them (eg 850, 998, 1098cc).

Thats what i was thinking, doesnt seem like theres many other places it could be leaking from so checking these might be your best bet

[Merlin-Mini]

Rocker cover gasket??

Rich

[ksj]

I should have mentioned it is a 998. I'm pretty sure it's not the rocker cover gasket. I'll try to put it onto ramps and see if I can then see the leak.
The term "tappet chest" is unknown to me (I'll research it). Would this really allow a quart a minute to leak out?
Thanks,
Joe

[Boycie]

That is a fair amount of oil Joe!

I'd say the covers are a possibility, there's very little at the back of the A series that can leak to that extent..



The picture above shows the two covers, with their central affixing bolts. (sorry to whoever I stole the picture from, one of the threads on here.) I'm also considering a leak as severe as your may be the main engine to gearbox gasket, also visible in the picture.

[ksj]

Yeah, the car leaves a trail about six inches wide down the road. It's good that the engine holds so much oil, so I got home without hearing any rattling.
Thanks for the photo of the engine rear. I was unable to find one myself. I'll put my hand down there and maybe I can detect the problem. It is coming from the right side, about in line with the bolt holding the rightmost tappet chest cover.
Joe

[ShoutforJoy]

Hi Joe

That's some oil leak. Is it a manual or automatic?

[ksj]

It's a manual. Totally stock.

[mattsminiresto]

The bolt head at 3 o'clock on the block is to prime the oil pump, never known one come loose but you never know.

Edited by mattsminiresto, 05 May 2011 - 09:26 PM.

[Boycie]

The bolt head at 3 o'clock on the block is to prime the oil pump, never known one come loose but you never know.

No that's the coolant drain point for the cylinder block IIRC.