torque converter leak

[taj34]

I have a 1986 auto mini that has been only recently started leaking a lot from the left side of the engine. Looking into it seems as though it may be the torque converter.
Is there anything I should know about torque converter leaks? How to fix it? On a side note my mini only leaks from there after driving over 65mph for at least a 30mins.
Driving slower for the same time and my mini won't leak.

Thank you,

[richard1]

I presume you mean the right side, as that is where the torque converter is.

Are you using a 10W-40 MA2 oil? And is it clean (not interfering with the pressure relief valve? If that valve sticks, you could be sending excess pressure to the converter.

[taj34]

Yes I am using 10w40 ma2 oil, the oil is clean. I will take a look at the pressure valve just in case.

[wimfournier]

When you find the pressure release valve in good order, maybe you have to look after the PCV (possitiv cranckcase ventilation). When it is blocked your engine will bild up crankcase pressure that is overwhelming the oil restraining ring in the crankcase.

[taj34]

Worked on the mini today. I checked the oil value, it was clean and working well. As for the crank case ventilation, how would I check that? Just remove the hose and see that its not blocked?

[wimfournier]

Well, just looking won't be enough.
There is a hose going to the foot of the carburettor, near the inlet manifold. 
The vacuum that exists behind the butterfly when th engine is running sucks air from the crankcase through this tube.
So, undo the tube from the carburettor and apply vacuum in the tube -meaning- put the end in your mouth and use your longs to create vauum in the tube.
When the system works, you should feel that the air pressuere in the crankcase is going down.
When it is not going down, there is an air leak. In the fitting of the other end of the tube?
When you can't create a vacuum in the crankcase; blow.
Build up air pressure in the system. When you feel that the pressure runs away when you stop blowing; there is an airleak obviously. Find it.
In the meantime you would have experienced when the tube or oil separator would be blocked, don't you think?

Good luck!

[taj34]

Did like you said, and it looks like there is a air leak. Also it looks as though my head gasket has blown as oil has seep though the gasket from the torque converter side.

[69hcode]

What year is your car. The oil fill is probably a breather so it won't hold a vacuum.

[g1drp]

Jun 12, 2017 4:12:38 GMT 69hcode said:

What year is your car. The oil fill is probably a breather so it won't hold a vacuum.

1986

[wimfournier]

Like 69hcode sais, when the oil fill cap is ventilated you have to undo the cap and hold a hand over the opening so it is air tight and than suck the tube to find out if there is an airleek.
But forget the thought that your headgasket would have been blown. When you find a trace of oil on the rim of the gasket on the backside of the engine than -may be- the gasket is weeping a bit. Clean the oil away with a spray of brake cleaner fuel and have a look after the next 100 miles if there is oil again. Don't expect it.

When ou have the tube off the pipe at the foot of the carburettor you can check if the inlet manifold has a vacuum and is sucking through te ment pipe. It should.
Tell us, where the tube goes. There should be an oil separator where the tube is connected to. You have to get sure that the separator is not blocked.
Since you did the test and told us that the vacuum did not get deeper when you suck more, this sais the separator is not blocked. So now do the test with a hand over the oil filler neck.
When the PCV is in good order, the air pressure in the crankcase should go down when the vacuum in th einlet manifold gets deep when you let loose the accellerator pedal. Than the butterfly closes the carburettor from the carb and full vacuum occurs in the inlet manifold. If you want, you cab experience that with the other end of the tube in your mouth and the tube connected to the little pipe at the foot of the carb. Playing with the accellerator pedal with running engine you should fel the suction that has to empty the burning gases that 'blow by' the pistons going up and down the cilinder walls.
When the suction is blocked, the blow by fills the crankcase with fumes and the atmosfericc air pressure goes up in the crankcase so that oil seeps  out at the oil seal rings on the crank. Most of the time the oil seal ring at the flywheel side is the week spot where the over pressure finds its way out and taking engine oil with it to the outside.
What we are looking after now, is, is there enough suction from the inlet manifold and is the PCV open enough to let the suction through to the crankcase.

[richard1]

We have gotten pretty off base from the original question.

-- The PCV valve (checked by blowing and sucking through it -- It should only let air out of the engine side, not into it) when clogged, causes increased oil consumption (burning) or in real bad cases, oil could come out of the dip stick if the oil level is too high. It will not cause a leak or pressure to the outside of the engine.

-- Valve covers can be a cause, as can various other assembly points and gaskets, o-rings, and seals.

The best way I've found to detect a the source is to start at the top of the engine and work down, using a piece of toilet paper to wipe the engine and all parts. When it get wet with oil, you have found a leak.