71T magnesium sweating oil?

[smiles11]

Can the mag case sweat oil on a 71T or would this be a leak from one of the case bolts? I can cinch it up to 18ft-lbs if necessary.

[dg567]

To me it looks like its coming from above the case bolts.

[smiles11]

What would that signify? The engine was rebuilt less than 2 years / 1000 miles ago

[EC900]

I heard that porous magnesium can “sweat” (microscopic) and with all the technological advances the ancient process is by far inferior to modern Mg alloys. Not convinced Mg will sweat to the point that saturation becomes physically visible.

If the engine didn’t “sweat” before the rebuild then it’s likely seeping from elsewhere higher up. Very clean engine btw, so maybe a $100 Borescope inspection camera (great tool to have for so many things) would help finding the seep easier for now.
Good luck and keep us posted on results.

[dg567]

Originally Posted by smiles11

What would that signify? The engine was rebuilt less than 2 years / 1000 miles ago

It doesn't signify anything - I've just come to terms that the magnesium case engines are more prone to weeping. Nothing you can really do about it. I'd just keep an eye on it and make sure its not getting worse and clean as needed.

[RSTarga]

That looks pretty damn clean to me. If you have doubts, wash the engine, once dry sprinkle talc around likely leaks and see what happens.
Can't really see, but the block looks like it may have some sort of coating.

[dannobee]

Get an oil dye kit and add the dye to the oil. Drive it on a decent length trip to where the oil reaches operating temperature, then inspect with the black light and yellow glasses. You'll see exactly where it's leaking or seeping.

[Magyar Kiwi]

Suggest you clean the oil off, drive the car and work out where the leak is.
Oil runs down under the influence of gravity, but can be pushed around by cooling air and airflow under the car.
Enjoy.

[callard]

What dannobee said!

[smiles11]

Thanks for the tips everyone. I recently had the entire underbody blasted with dry ice. I noticed the weeping after about 300 miles after I had the dry ice completed.

Btw, I will be posting some before & after photos of the dry ice work soon for those that are interested.

[dg567]

Did they dry ice the motor? A buddy of mine had his engine oil cooler damaged after he had his car dry iced.

[smiles11]

The motor already looks great so that wasn’t dry iced. I only had the suspension, calipers, underbody tray, control arms etc done.

[icarp]

Two thoughts, i think some cars left the factory with cases Weeping oil
The only sure fire way to fix any and all oil leaks , Drain All Oil Out !!!
Leave it dry. Then add oil and drive , simple right

Just drive the piss out of it. 6,000 rpm plus

When the rebuild happened there is no way to know what brand of seals and gaskets or sealant
was used .

Enjoy the drive , 5,000-10,000 miles a year not 10 months in thegarage

Ian

[pmax]

Well, is there oil in it ?

Originally Posted by icarp

Two thoughts, i think some cars left the factory with cases Weeping oil

Didn't factory coat them with cosmoline ?

[jerrykrug]

smiles11, can you share more info about the ice blasting - who, where how much? might want to have some done. keep us posted if you solve your oil leak/weeping

Thanks
Jerry

[PeteKz]

Originally Posted by pmax

Well, is there oil in it ?



Didn't factory coat them with cosmoline ?

Cosmoline is on the outside and won't seal oil leaks. It's a thick wax, so oil will dissolve it eventually.

To deal with casting porosity in the early 20th century, automakers used an oil-proof paint called Glyptal and coated the inside of the block with it.

[Dan J]

A friend of mine was in Viet Nam. He said if a Huey helicopter wasn't leaking oil you shouldn't get in it because that meant it had all leaked out

[pmax]

Originally Posted by PeteKz

Cosmoline is on the outside and won't seal oil leaks. It's a thick wax, so oil will dissolve it eventually.

To deal with casting porosity in the early 20th century, automakers used an oil-proof paint called Glyptal and coated the inside of the block with it.

I would think the Cosmo stuff is "oil resistant" given where it's used and how the coating or remnants anyway lasted thru decades of exposure.

[PeteKz]

https://en.wikipedia.org/wiki/Cosmoline

[B_El]

Following for NorCal dry ice information...