Valve train Sludge (including gray!) 1966 401

exchaoordo

exchaoordo

Member
Symptoms: 1/16th+ of sludge inside the cover. Passenger side (which had a clean PCV on, though no idea what went before) much worse than drivers (with a breather). No valve noise, good compression. Under the black stuff is gray stuff (see pic). Looks like "liquidy"/melted RTV. Does that tell me anything? Exhaust spits oil too. Related?
I've driven the car only maybe 30 miles since I got it in mid-August.

Valve Train Gray Sludge 11122021.jpg
(Forum replies from similar questions include: Marvel Mystery Oil, Sea Foam, Gunsmith Brushes, Detergent gasoline, none of which gives me confidence.)
 
A 66 is an old engine. Unless it has been rebuilt in the last 25 years it could look pretty bad because oil did not have all the cleaning additives that modern oil does. When was the oil changed last? If the engine runs good and does not smoke, clean up the valve covers and drop the oil pan and clean it up. Clean up the oil pump pick up screen. Put it all back together. Do not put any special chemicals in the engine to clean it up. Do not use any synthetic motor oil. Put some old style 30 weight detergent motor oil in it and drive it for 500 miles. Monitor oil pressure and engine oil level. It might have a lot of miles left in her.
 
For some reason it appears to be a normal situation I've seen on MANY vehicles where the PCV valve is on one cover & a breather on the other. Remember clean fresh air is coming in the breather & circulating through the engine & then into the PCV valve.
As far as the "Gray" stuff. It's the buildup of the lead that was once used in gasoline & like mentioned the older oils not having the cleaning properties of the newer oils. Also has something to do with the ZDDP additives put into the older oils which ALSO leaves gray deposits.
Best thing you can do at the moment, IF you want to get somewhat involved, is drop the oil pan & remove the pick-up screen & clean them out as mentioned. Driving only 10 miles a month is NOT enough to rid the crankcase of any moisture build-up that happens when only driving very short distances.
IF you don't want to be bothered drive the car for at least one hour, at highway speeds not around town, & while still hot drop the oil & filter every hundred miles or so for the next 500 miles & you will slowly see the oil will be cleaner each time you change it & it will stay cleaner for longer the more you do it until things come back to normal.

Tom T.
 
Thanks both. Zinc! I looks like zinc for sure now that you mention it. Tom, I promise I will drop the oil pan etc. to do the rear main seal! The weather keeps turning nice, which has so far prevented me from doing the job. :)
 
exchaoordo said:
Not excited about burning lead. '-)
Click to expand...

tom telesco said:
For some reason it appears to be a normal situation I've seen on MANY vehicles where the PCV valve is on one cover & a breather on the other. Remember clean fresh air is coming in the breather & circulating through the engine & then into the PCV valve.
As far as the "Gray" stuff. It's the buildup of the lead that was once used in gasoline & like mentioned the older oils not having the cleaning properties of the newer oils. Also has something to do with the ZDDP additives put into the older oils which ALSO leaves gray deposits.
Best thing you can do at the moment, IF you want to get somewhat involved, is drop the oil pan & remove the pick-up screen & clean them out as mentioned. Driving only 10 miles a month is NOT enough to rid the crankcase of any moisture build-up that happens when only driving very short distances.
IF you don't want to be bothered drive the car for at least one hour, at highway speeds not around town, & while still hot drop the oil & filter every hundred miles or so for the next 500 miles & you will slowly see the oil will be cleaner each time you change it & it will stay cleaner for longer the more you do it until things come back to normal.

Tom T.
Click to expand...
Well, lots more gray stuff in the oil pan sludge. There's some RTV in there too. I'm working toward the rear main seal but it looks as if I'll have to remove the oil pump to get at it, no? If so, I'm going to need some gaskets.
 
Myself, if I decided to replace a rope main seal, I would just pull the engine out and apart, and lift the crank out. I just can't see a good replacement of the seal any other way.:( I have tried the "sneaky pete".
 
That's on the agenda, eventually... so much else to do meanwhile.
Bob said:
Myself, if I decided to replace a rope main seal, I would just pull the engine out and apart, and lift the crank out. I just can't see a good replacement of the seal any other way.:( I have tried the "sneaky pete"
Bob said:
Myself, if I decided to replace a rope main seal, I would just pull the engine out and apart, and lift the crank out. I just can't see a good replacement of the seal any other way.:( I have tried the "sneaky pete".
Click to expand...
Click to expand...
 
tom telesco said:
I explained how to do it in the car. For the most part it's pretty simple. I've done it MANY times, so much so I could probably do it in my sleep.

Tom T.
Click to expand...
Am I removing the oil pump to get at it? Don't mind doing it, just can't find the gaskets for sale (other than in a repair kit).
 
If you are going to deal with old cars you should learn how to make gaskets. You can buy a selection of gasket material at an auto parts store. A scissors and a ball peen hammer and you will soon be making gaskets as good as the gasket maker companies.
 
Thanks, yes! I have made gaskets before and the ball peen technique is ingenious. But my usual techniques didn't work well for this one because I didn't want to fully disassemble the unit. I'm proud of my ingenious solution (though I'm not genius): I grabbed a pic from a pump replacement for sale and scaled it properly. Ta-da! A templet.
Oil pump gasket template.JPG
 
And many thanks to Tom for all the advice and parts. Can't say I did it perfectly, but now I can't wait to do another one.
 
Hmmm.... not thinking I licked it. I may have to do it again. It leaked at first for sure. Trouble is it hasn't been on the road much since. But I'm pretty sure I did something wrong.
 
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