Exhaust smoke from oil filler

[Strange Rover]

So as some of you may remember, I had an engine swap to do on my poor old girl because it was running like a total wreck. Thankfully one of the guys was kind enough to donate me an engine he had sitting around, with less than half the miles on it that my engine had (from 300,000 to like 130,000).

This is my first hands-on vehicle so I didn't really know what I was doing but I managed to get the new engine swapped in just fine. Now... the new engine won't run, go figure. I tried fiddling with the distributor timing to try and get it to go, I know for sure the firing order is correct and I'm not 180 degrees out. No amount of tweaking would get it to run but it did sputter and fire a few cylinders here and there. I think it's got bad rings but I don't have a compression tester to check it, I'll have to get one. But whenever I tried to start it, the engine was making these odd metal clicking sounds (which I later found out was the oil pan being inflated/deflated) and you could hear like... air hissing out of the engine? So I thought to take the oil cap off and try it again. The bloody thing starts puffing exhaust smoke right out of the oil cap like some kind of tug boat or something. Being someone who has never really worked on cars before, I'm sure you can imagine my confusion/surprise. Luckily the gears in my head did manage to keep turning and I figure it's almost certainly the rings but I have no way to check for sure until I get hold of a compression tester. I assume the heads and valves are good because I was told it had a valve job not long before it was pulled.

I was told the engine ran really well when it was pulled but I think it did sit for quite a while in the garage and perhaps the rings are stuck to the pistons and not making a good seal. I just want to know if anyone has heard of this problem before and could maybe let me know if my guess is totally off, or perhaps if it might be something else? Can I just take the crank and pistons out from the bottom so I don't have to pull out the damn engine again? Is it super difficult?

[red90]

Could be a head gasket as well.

[ANDYD]

Could be a broken cylinder ring, but knowing these engines reputation, I have to agree with Red, likely head gasket symptoms ......let us know what you find

[red90]

Do a compression check first and see what cylinder is the problem. To check rings, run a check, then squirt in some oil and check again. If the compression goes up with the oil, it will be rings.

You could, I think get the pistons out and rings changed with the heads off and the engine in place....but it is a pretty hack job as the bores need to be honed as a minimum. Maybe if you are desperate for the lowest cost, easiest fix, see if it is just one cylinder with the compression check and pull that head.

[punkinracer]

Geez took yah long enough to get the engine in!! Just Kidding! The engine did sit for a couple years, so the rings may be sticking in the skirts a bit - maybe. It turned over by hand fairly easily. You might want to squirt something down the bores to loosen up the rings if they are sticking, won't hurt anything.
Pat

[Strange Rover]

Geez took yah long enough to get the engine in!! Just Kidding! The engine did sit for a couple years, so the rings may be sticking in the skirts a bit - maybe. It turned over by hand fairly easily. You might want to squirt something down the bores to loosen up the rings if they are sticking, won't hurt anything.
Pat

It's been in there for a while now but I haven't touched it since before the holidays. Just decided I'd see if anyone had seen this issue before.
Seems confusing that a head gasket would cause puffs of exhaust smoke straight from the oil cap like that but I guess anything is possible. You can put your hand where the cap goes and you can like, feel the puffs of exhaust and air blowing out. Seems like a whole wack of blowby, like even to the point where the engine won't run. I can get a few cylinders to kick here and there but mostly it just cranks and puffs air. I know the ignition system is good and it's definitely getting fuel and air so all I can think of is timing (which we fiddled with for hours) or compression. I'm going to have to compression test it and see what's going on in there. It's not backfiring out the intake so I don't really suspect a valve issue but I suppose that's possible, too.

Thanks for the insight, all. I'm a bit bummed to hear you can't just pull the rotating assembly out from the bottom. I was really hoping I could leave the heads on and hone the cylinders from underneath, assuming the problem turns out to be rings at all.

I just want to get the old beast back on the road without spending a whole ton of money, which I don't have. You know how it is.

[punkinracer]

I really doubt you have a ring issue, something else is not right here. Fuel and spark are good signs. I assume that the distributor is from your old engine? Check your timing again. Set number one piston at tdc, and check if your rotor is pointing at number one spark plug wire.
Pat

[Strange Rover]

I already did that, though, unfortunately.

Timing was the first thing I suspected when it wouldn't start. I started with piston 1 at tdc and made sure the rotor was pointing at one of the nibs in the cap. Then I set that as piston 1 and set it up so the firing order was correct, as per the users manual that came with the truck. It wouldn't start so I tried advancing it a little bit since I think the correct timing for these is around 12 degrees advance. Still wouldn't run. Eventually I got the timing too far advanced and the engine would kinda go-stop-go because it was firing too early. So back the other way a bit, still nothing. Just a few little burps here and there as the occasional cylinder would fire. Sometimes a few of them would fire in a row and it sounded like it might run and then... nope... so close.

Kind of confused at this point, and it doesn't explain the engine inflating itself with air or the exhaust puffs coming from the open oil cap. I mean even if the rings are kinda crappy on a few of the cylinders it should still run, at least a little bit. I can't seem to get it to run or idle at all... a real head scratcher.

[Rob]

How old is the gas in the tank??? Gas turns bad pretty quickly these days. If you have enough compression to get some firing then the motor should run (though not well necessarily). Look at spark and fuel delivery. If you need a compression tester you can borrow one of mine.

Ditto to Pat's idea of soaking the rings. Rislone works well but plain old diesel can do the trick as well just not too much so that it doesn't hydro-lock when you try to turn it over (n=that can ruin your whole day... don't ask me how I know). Just be sure to have the plugs out when you crank it to get the fluid out and it might take awhile to soak so be patient.

Good luck

Rob

[punkinracer]

A certain amount of crankcase pressure is generated from the bottom of the piston as well as the top side, I doubt it's a ring issue since you are feeling pressure there. the oil cap is vented, I think, and there should be a few more somewhere as well. I think there is a vent on the timing cover, check and make sure it is unblocked. Can you feel exhaust out the muffler as well? What goes in gotta come out right!
If the head gasket is blown, which I still doubt, it would still at least start so I wouldn't go down that road until the engine is running first. Even though this engine was sitting a few years it ran perfectly well when I took it out, so I'm sure that it is something that was swapped in not being correct. Triple check your timing, I think you've got it 180 out. Pull the valve cover and make sure that both valve are closed when #1 is a tdc and the marks on the balancer are lined up.
BTW I hope you replaced the valley pan gasket like I told you to before you put the engine in, that thing was barfing oil out like the Exxon Valdese!
Pat

[red90]

Seems confusing that a head gasket would cause puffs of exhaust smoke straight from the oil cap like that but I guess anything is possible.

It would be caused by a leak from the cylinder to under the valley gasket. Could be rings as well. Grab a compression tester and check each cylinder wet and dry and report back.

[Strange Rover]

BTW I hope you replaced the valley pan gasket like I told you to before you put the engine in, that thing was barfing oil out like the Exxon Valdese!
Pat

I sure did! I replaced all the missing parts and I changed that valley gasket, as well.

I'm going to try and get my grubby little mitts on a compression tester just to rule that out. I did try switching the timing 180 (more than once, in fact) and that was no help. I'll double check it with the valve cover off just to be completely sure I'm on the right stroke. I think I'll also take Rob's advice and try to put some fresh fuel in it. I suppose the fuel has been sitting in there for a while now and may have gone bad... but shouldn't it still run a bit? Another thing I'm going to check is that breather canister on the passenger side valve cover. Maybe it's plugged up with spider webs or something, eh?

[Gromit Dog]

This reminds me so mmuch of timing issues I have run into.

I know you have done this BUT...

when you check the timong on Cyl one. make sure of these things:
You have cyl one.. the furthest forward (not always easy to tell)
You MUST be on compression stroke. There must be air pressure comming from the spark plug hole when you crank it up to tdc
Check you are at TDC with a piece of rod or hanger in the plug hole. I have seen timimg marks on the balancer be WAY off.
Remember..."Suck Squeeze Bang Blow! or in other words Fuel Compression ignition exhaust on a 4 stroke engine.

And most importatntly:

Make SURE your plug wires are not only Good, but in the correct order and location. I had a RRC that had not runin years because each plug wire was one position out. It did the same thing including making scarey popping noises from the valley pan. When it finally ran I think I murdered every mosquito in a 5 mile radius, but after a run down the hiway the smoke stopped.

Hope she runs for you soon!