Hole in the block & grey goo

[JVA]

I have gotten positively nowhere on my whole carb issue - had some home improvement projects that took priority over Cadillac parts. But, I figured an intake manifold gasket was something I can do that was within budget, so I ordered one. While I was in there, I took the pushrod cover off to clean it up - it was covered in sludge and debris, and maybe the source of a vacuum leak. $6 gasket, no worries.

In the valley, near each pair of rockers was what looked like a little sludge buildup, so I started to wipe it away with a paper towel. It was not just sludge.

If that wasn't bad/surprising enough, I found a hole in the block. Or, what I assume is a hole. It's jagged, so I can't imagine it's supposed to be there.

Take a look:



The goo was NOT all spread out like that when I found it. I was black and looked like sludge - just like the little pool on the right. When I wiped it with a towel the goo was "exposed" and spread around.

The hole doesn't really look like it should be a problem - anyone have a different opinion? What's more troubling to me, though, is how it got there.

The goo feels like anti-seize, and spreads like anti-seize, and brake cleaner has about the same effect on it as anti-seize. But what the happy heck would all that anti-seize be doing down there??? After multiple treatments with brake cleaner and carb cleaner, I got it mostly cleaned up. But, it left a thin film everywhere that doesn't wanna get any cleaner:



I've owned a lot of cars, but never one that felt so much like a rabbit hole... the kind that gets deeper and deeper...

Any thoughts/opinions are welcome.

[Jeff Wilk]

Several engine rebuilds here too and only time ive seen anything close to this was similar grey goo on a cracked head. Question, is there another cast hole towards the back for oil drainage or is this jagged hole actually just a very bad cast oil drain hole?

[Glen]

You don’t say which engine it is, but it looks like a 472/500 block. 

Others may be better to answer than I, but I believe this is the oil drain back hole and it came from the factory that way.  It has been a while since I’ve had one of these engines open but I seem to remember that hole. 

I believe the gray goo is most likely water and oil mixed, which is a problem.  How is the oil in the pan?  Is it gray too?  If not then the water leak is small and at the top of the engine. 

[Philippe M. Ruel]

I've seen similar large cast holes on other blocks, 100% from factory. I wouldn't worry for that.

Mixture of engine oil and engine coolant typically produces this kind of "salad dressing" you are showing.
I removed about 1 lb of a more sludge-like "grey goo" from the bottom of my 331 oil pan - probably never disassembled in 60 years - with a filling knife.

[JVA]

Wow! 1lb!

This is a 429 on a '67 Fleetwood. I've owned it for almost exactly three years and in that time done three oil changes. There has never been any questionable results from oil changes, nor in the ~3000 miles the car has done been any conspicuous oil or water consumption. I have not had the oil pan off, however. Aside from a minor ATF leak, the car leaves nothing on the ground so there hasn't been any reason to take anything apart. Seems like the consensus is oil:water contamination?

[JVA]

I posted this on another board I frequent (non-Cadillac) and someone suggested it could have also been the result from condensation forming when the engine is shut off, collecting in the valley and not getting burned off (engine wasn't run long enough) or sucked out (PCV not working). Since I actually started on this to address a weak PCV and in the process found the cork gasket on the cover was one notch above useless, that also seems like a reasonable explanation. Since I'm not using any fluids and oil changes look good, I'm going to assume this is the result of atmosphere and maintenance, and not an actual problem.

Thanks!

(And if that second picture is bugging you as much as it's bugging me, yes, I am going to buy some paint and fix those valve covers. )

[66 Eldo]

As mentioned, the hole is supposed to be there for oil draining. The gray sludge is not normal but not uncommon. I have seen this twice on both of the 472s I went into to replace the lifters. They were both low mileage cars just driven around town. ( this was in the early 80s) Your theory of the condensation I think is correct.

[JVA]

Hopefully with a properly sealed pushrod cover the PCV system will be a little more effective! With the bulk of that goo gone, perhaps the rest of it will get washed away over time. I never drive this car truly short distances, but who knows what it spent '67-'10 doing.

I have some new gaskets and some POR-15 in Cadillac Dark Blue coming. Hoping to tidy up the engine bay a little. Figure even if I can't fund actual repair right now, I can at least get it looking proper.

[cadillactim]

Looks like condensation to me.  Once I bought a 53 Chevy which started and ran fine, but had been setting for a long time.  I was changing the oil, and a lot of water drained out first before the oil.  Actually worried me at first, but later learned it was simply condensation from all the setting and no driving.  Car never gave me a problem afterwards.

Make sure you PCV system is working properly.

Tim

[Scot Minesinger]

This hole at least on a 472 is normal and ordinary.  I took apart a decent running 472 with 100k miles on it to re-seal it only, and sent the heads out for a valve job.  This hole was there too.  Almost looks like a photo of my engine (the first photo).  That sludge is years of build up with tens of thousands of miles.  A serious problem where anti-freeze and oil are mixing would have other more obvious symptoms.

[RyanBurman]

The old detergent oil they used to use in these will make a nice coating like that that will last a long time even through some oil changes. If the car was seldom driven and only short distances and then sat for a long time before you bought it this combined with the condensation theory would have this result. Whenever I do oil changes I get the engine warmed first to thin out the oil and with any luck get more crud out of the engine by thinning it up a bit too.

[Thee_Audacity]

I am rebuilding a 429 also and my valley has the exact same hole.  It's just a rough casting.  Consulted my local machinist who does lots of early Cadillac motors and he says that he's seen this many times and it's nothing to worry about. 

Scared me also. 

[JVA]

All good to hear stuff! The issues this engine seemingly spontaneously developed have got me on edge. I really think the core problem is carb (or *maybe* ignition) related, but anything out of the ordinary seems like a potential crisis.