Mysterious engine sludge after 403 rebuild

[Rob]

Have a look at the pictures ...

I had my 403 rebuilt 2 years ago. I had some #5 heads from a '68 350 rocket bolted on. No work was done on them except for a basic surface grind, new exhaust seats, and new valve guides. Due in part to some shabby machining and my engine builder being less than reputable, both head gaskets started leaking almost immediately after the build was done. I also noticed that the car was losing a considerable amount of coolant, but oil also. It was losing a quart of oil every 500 miles.

I wasn't furious or anything, but I knew I wouldn't be taking the car back to the same person. The head gasket leak gave me the excuse to tear off the heads and put some more work into them that I neglected to do originally (new/bigger valves, porting, bowl work, valve job, etc). I had a local Olds engine guru do this work.

Anyway, upon his removal of the valve covers and intake, he found a considerable amount of sludge in the intake valley. He had no idea what it was exactly, and how so much of it could have accumulated in such a short time.

The engine had less than 5000 miles on it when these pictures were taken!

We determined that the coolant wasn't leaking internally, which was a relief. But the oil loss and this sludge is still a mystery.

Any idea where all of this could have come from??

 

[maven]

the mixture in the rocker covers looks very much like water contaminated oil. could just be from condensation.....short trips, too cold thermostat, etc. basically just never getting hot enough to boil condensation from the oil.

The valley sludge looks like a blocked PCV(or any other source of poor crankcase ventilation) or a leakingEGR concern....which links right back to improper crankcase ventilation....add exhaust to the valley and youll get interesting stuff like that.

 

[maven]

the intake valves all also have pretty heavy buildup. Which could be leaking valve seals, or again....a PCV issue.

 

[88hurstolds]

By the looks of the intake gasket surface on the head the EGR/intake bypass was leaking right into the lifter valley area.
How much material was shaved off of the heads?
Did he also shave the intake to compensate? (doubt it)
It looks like you could have port mismatching causing the intake, coolant and EGR ports to sit too low in alignment to the intake ports and thus coolant leaking into the lifter valley area causing your sludge issue and quite possibly exhaust as well due to the mismatch.
I don't think simple environment moisture can cause that much sludge.
Exhaust contains water, it's a byproduct of the combustion process and could very well have also contributed to the sludge.
I would kick that machinists *ss... piss poor job.

 

[Rob]

The heads were milled "just enough to get the surface flat" was the way the machinist put it. Aside from that, all he did was install hardened exhaust seats and new guides. No work was done on the intake side at all, the heads were simply bolted on as-is.

Part of this was my fault, I had too many hands in the fire. I had one guy do the heads, then I took them to the engine builder who bolted them on and did the rest of the engine rebuild. Neither one of these people turned out to be very reputable. Since I brought the engine builder the heads, it made it a "custom build" so he wouldn't warranty anything on the heads. I also told him that I wasn't building the car for all-out performance but rather as a mild upgrade over stock. He used this as an excuse to cut corners, including not degreeing the camshaft and not port/gasket matching anything.

So no, the intake wasn't machined at all.

After the head gaskets started leaking, I took the car to someone who specializes in Olds motors. He completely redid the heads the way they should have been done the first time: new 2.07/1.71" valves, opened up the bowl area, fully ported, port matched to the intake. Also installed a new camshaft and chassis dyno tuned and tested.

However, I'm not sure whether or not the "sludge" issue was solved. The engine still seems to be losing oil at a rate higher than normal. I'm using Shell Rotella 15W-40 as recommended by the engine builder, a lot of people swear by it on here also.

How would I check to make sure this isn't still an issue? How would I determine if it's a PCV or EGR valve issue? And no, I don't want to pull of the intake ... not right away anyway.

 

[maven]

Pull a rocker cover and see if its still clean in there.....

Do you have a pcv system?

 

[tc1959]

It looks like coolant seeping past the head gasket. I have seen this before.
I would recommend having the block and heads magnafluxed and checked for cracks.
Have the deck height checked and the intake checked for any problems.
The picture of that valve cover is definitely coolant mixed in with the oil.

 

[Rob]

I wouldn't be surprised if that was oil/coolant in the valve covers. But I don't see how a head gasket leak on its own would cause that.

What I'm concerned about now is whether or not that issue was solved during the 2nd rebuild. I do know that the block and heads were magnafluxed and there were no issues. The heads were port matched to the intake this time.

 

[pontiacgp]

are you sure that is the engine that was rebuilt or is it possible they just dropped in another used engine and kept the rebuild

 

[olds307 and 403]

Your breather and pcv valve will be full, if it is an issue. It could also be unseated piston rings. My Olds 350 in my 4x4 is using oil and fouls two plugs after time. It needs a rebuild, pretty sure it has stuck oil rings. It has similar sludge.