Engine time

[Stanley]

Pulled the plugs. All six had a liberal coating of fresh engine oil. That seems to make my idea of a broken ring  unlikely.

Edited July 21, 2017 by Stanley

[Captain Obvious]

Did you do a compression test? Can you see any holes in pistons looking in the spark plug holes?

With the plugs out, you should be able to move the pistons around pretty easy and get a decent look at all the piston faces.

 

[Stanley]

No. Can't get a wrench on the pulley nut without removing the fan shroud, and have to pull the fan to remove the shroud, so it's a bit of work.  

I don't see how something that happens in one cylinder gets oil in them all. Didn't lose any coolant. Didn't see any oil floating in the radiator. Lost oil though, in just a two block drive.

I'm trying to come up with an idea but I've got nothing. I don't think anything was rattling around in a cylinder. I've heard that before, a small nut that my Chevy inhaled; it was loud.

 

Been using the truck for storage. Hadn't driven it for about a year and a half but put in some gas and it started right up. Header is shot, rust hole got bigger since I looked at it last.

Edited July 21, 2017 by Stanley

[Zed Head]

The oil in the filter housing probably got distributed through the carbs back to each cylinder.  How it got in to the filter housing is still a question.  It could have come back through one carb, from one cylinder, or through the PCV hose.  How about a bad valve seal, and maybe guide, on one cylinder, on the intake valve, fouling the plug so there's no fire, then sucking oil in from the head and pushing it back through the intake runner.  

It's odd that the problem seems to have occurred either while the engine was off and sitting, or at the restart.

Edit - I'm liking a PCV hose route more than a valve seal.  Just because there's more air velocity.  Any chance that you got a hole in the crankcase seal somehow?  Rear main seal blowout, cracked valve cover, oil pan falling off?  How about a plugged PCV valve?  I'm not clear on the carb PCV system.  I do know that they can cause problems when they go bad.

Edited July 21, 2017 by Zed Head

[Zed Head]

Old engine , blocked PCV = lots of blowby pushing oil and blowby in to the filter housing from the valve cover?

 

 

[Stanley]

It has the individual K&N's on each carb.

I put a little catch can at the low spot in the middle of the hose from the crankcase vent to the PCV valve. It picks up a spoonful or two of oil in a year so there is some blowby.. I emptied it a month ago. Keeps oil out of the PCV valve. PCV valve was new couple of years ago. 

It ran OK except for the smoke the two blocks from the store, surprising with all that oil in there.

25 minutes ago, Zed Head said:

It's odd that the problem seems to have occurred either while the engine was off and sitting, or at the restart.

Yep.

Edited July 21, 2017 by Stanley

[Stanley]

If it came through the PCV hose, the inline strainer should be filled to the brim. I'll check it tomorrow. The crankcase vent tube is well above the oil level in the pan, though, so where would it be getting all that oil ?

 

[Zed Head]

That kind of just leaves the PCV hose as the source to distribute oil to the carbs and the cylinders.  A pressurized crankcase.  So a hole or broken rings or blown head gasket sounds likely.  I'm back to head gasket.  Things move and twist around when the engine cools off.  Fits the fine when parked, bad when started scenario, I think.

Good luck.  

Edit - The volume of blowby gas, carrying oil vapor, would increase dramatically after the hole, or broken ring, or blown gasket.  Just a guess.

Edited July 21, 2017 by Zed Head

[Captain Obvious]

I still think a compression test will highlight or rule out a multitude of potential issues, but if that doesn't come up with anything, then I've got one WAG based on past experience. Let me tell you a story...

I once had a car that ran rich for several reasons. The bowl level was a little high (because I was too lazy to fix it), the jets were a size larger than stock (because I was a kid), and the accelerator pump linkage was a little too touchy and set off a burst of gas with too small of a pedal movement (because I wasn't smart enough to figure out how to fix it). Also, when I would park the car hot, it would percolate some fuel from the carbs and bubble a little over into the intake manifold.

During the hot summer months, every now and again it would make this big "whoosh" sound while cranking, and it would let out a big cloud of whitish smoke, and it would then smoke for a couple minutes until everything seemed to settle back out to normal.

Looking , back, I believe what was going on was that through the rich running and the percolation, I was mixing unburned gasoline in with my oil in the crankcase. This would actually create a volatile gaseous mix of air inside the crankcase, and if it reached the right mix of air to fuel, would spontaneously burn off as I was cranking the engine. And after an "event", it took a couple minutes to burn off the residue that got burped (vurped) into areas where it didn't belong (like into the crankcase ventilation system).

Like I said... WAG, but my question would be:  What does your oil smell like, and when was the last time you changed it?

[Stanley]

Interesting, C.O. It had been running rich for some time, about 6 months or more, and the oil hadn't been changed for about a year. It had also been hard starting that time due to worn out points and points cam, so it was pulling extra gas each start. I had considered gas in the oil before this happened and was planning to change the oil. I bought oil and filter a couple weeks ago but didn't get around to it.

I've got a pair of ramps I use to change the oil, but the car has to be running to get on the ramps.

There's also the intermittent rattling sound, not very loud, that I heard coming back from the store. I thought it might be a piece of broken ring in the pan getting knocked around by the crank counterweights. Possibly it was a coincidence. I was listening carefully for engine sounds on that smoky short drive. The alternator has a bad bearing that has been getting worse. Bought an alternator but swamped with work so didn't get to that either.

Edited July 21, 2017 by Stanley

[Patcon]

3 hours ago, Stanley said:

I thought it might be a piece of broken ring in the pan getting knocked around by the crank counterweights.

I don't think a piece of ring would ever hit the crank. It would fall to the bottom of the pan and stay. Now a piece of piston skirt might hit the crank but I believe there is more clearance than even that between the pan and the crank.

I agree with CO, compression test will narrow the possibilities...

[Stanley]

Gave it a try today. Pulled the plugs again, cranked the engine with the plugs out. No noises and no oil came out. Cleaned the oil off the plugs and replaced them. Started it up, no engine noise but a little smoke. Pulled the hose off the PCV valve, it was OK, plenty of suction. No oil in the inline strainer on the PCV hose. Listened to each cylinder near the plug with the D.I.Y. stethoscope. No bad noise but #4 sounded slightly rougher. Took a drive around the parking lot, some smoke but not a lot. No engine noises.

Took it on the street, drove about a mile to a gas station. I was watching for smoke, there was a lot from time to time. When I was on the way back there was a "death rattle" like the sound it makes when the engine overruns as it's shut down. Lots of smoke. Got back with no issues other than smoke and parked, it overran again when I shut it down. The idle is a bit high which might cause the overrun. Guess I'll just be driving the truck for a while.