That hard gray paste in older cars' oil pans, heads, etc. 1

[Tmoose]

The stuff that takes a scraper to remove from corners and low spots. Comes off in chunks sometimes.

There are plenty of stories about what that gray stuff is, and isn't.
Like zinc from ZDDP, or the final result of moisture from combustion byproducts the non-detergent oils couldn't handle, and so on.

My favorite is lead from "leaded" gas.

1 - Does anyone know what it really is?
2 - Does anyone know A simple inexpensive chemical test to differentiate lead from zinc. Anything from color change to Class O G pyrotechnics is fine.

thanks

Dan T

 

[MikeHalloran]

https://www.google.com/shopping/pro...lsft=cm_mmc:Shopping-_-LIAs-_-D24-_-203313743

Mike Halloran
Pembroke Pines, FL, USA

 

[Tmoose]

Thanks Mike.

I do love Home Depot/Lowe's/NAPA/McMaster solutions.
Almost as much as "found on the side of the road on trash day" solutions.

 

[MikeHalloran]

Please do report your results.
I've always assumed the gray stuff was lead. The last engine I found it in was a 390 Ford that had gone 100,000 miles at ~10 mpg on premium gasoline. I loved that car.



Mike Halloran
Pembroke Pines, FL, USA

 

[Tmoose]

Hi Mike,

It will be a while for me, but I promptly sent the link for the 3M test kit to an old car forum to stir up some trouble.

regards,

Dan T

 

[RossABQ]

Resuscitating Ford Flatheads, I've seen plenty of the stuff. I'd suspect it isn't "just" lead from gas, or tin/lead/babbitt from bearings, but a combination of several things. So the test kit may hit on the presence of lead, but a full analysis is likely needed.

A lot of the old guys still swear by non-detergent oil. See the results below.

 

[dicer]

So are you talking about combustion deposits or gasket sealer?