Oil Load Up?

[jemarshall64]

Ok, for starters,

1) vehicle model. terra
2) production date/or year model. 1977
3) two wheel drive or four wheel drive. lockright front, possi rear
4) type of transmission (and transfer case if applicable). t19 wide, Dana 20
5) if 4x4, which axles front and rear. Dana 44
6) which engine variation. 196
7) which ignition system variation. petronix w/msd
8) which fuel system variation. propain
9) which brake system variation. stock
10) non-oem modifications present which May impact a response SOA, bobbed , high steer, reverse shackle, hydro assist

So the problemis this.

When coasting downhill with the tranny holding the rig at speed, I start to get a real strong smell of burning oil. Smells like heavy oil burning off exhaust. Looking back, its puffing blueish smoke out tail pipe. Motor kinda stumbles a little. Step down on throttle and it blowes the blue smoke pretty heavy for a second and responds like a carb thats loading up, then clears up and smell and everything goes away.

This happened once on a trail, and once on pavment. Was moving at no power steering trail speed, and on pavment was coasting at about 25 mph. Both times I was nose downhill, but not sure if that matters. Looking motor over there is no sign of valve cover leaking, only leak right now is from the rear main area, but I think its the flywheel bolts. The rig has been in continous build mode for several years, but the motor has less than 2000 miles on it since rebuild in 05 or 06. The smoke that comes out reminds me of the inital start-up puff from vlv seals, but I have never heared of anything like this while the vehical was running, defanatley since I am running propane. Any help would be great, thanks.

 

[FDChappie]

Most likely intake valve guides with the next likely being rings. Being as it's propane I'd vote for guides. If compression is good on all cylinders definitely guides.

During deceleration high vacuum is created in the intake manifold. Under this condition, worn intake valve guides will allow oil to be sucked from under the valve cover and into the intake port. From there it goes into the cylinder and forms your smoke cloud.

 

[jemarshall64]

most likely intake valve guides with the next likely being rings. Being as it's propane I'd vote for guides. If compression is good on all cylinders definitely guides.

The heads were completly rebuilt when engine done. New guides, umbrella seals, and bbc springs.

during deceleration high vacuum is created in the intake manifold. Under this condition, worn intake valve guides will allow oil to be sucked from under the valve cover and into the intake port. From there it goes into the cylinder and forms your smoke cloud.

This is like it could very well be, but seals guides have very little wear.

I have not done a compression check yet, but besides this new development, she runs like a watch, will get one done soon.

 

[Robert Kenney]

I'm guessing the oil is coming through the pcv system. I say this based on what you say has been done to the heads. Test and see if it will blow smoke after idling for a while like one minute. If the intake valves are to blame it will suck oil by at idle too.
P

 

[jemarshall64]

Standing here in drive way next to it, been iidling more than 5 min and no smoke. Had just got back from run up the hill less than 1/4 mile, and it did it again comming back down the hill to the house.

 

[Robert Kenney]

I forgot to mention that after idling it will blow some smoke if you rev it a bit. The flow through the manifold and by the valve will carry any oil into the cylinder and burn making smoke. I definitely suspect a pcv system problem.

 

[jemarshall64]

Tried idle than reving and still wouldent blow smoke. Really hope it can be a pvc problem. Will clean it tommarow, but heading out for weekend with it, will see how it does.

 

[Robert Kenney]

You need to replace the pcv valve itself if you are not sure it is good.
Under high manifold suction like at idle or deceleration the valve mostly shuts off limiting air flow so oil won't be picked up like you see. Under acceleration or low manifold suction conditions, the valve will open allowing larger flow potential but because the suction is low the flow is low and no oil is drawn in.
Post a photo showing the pcv routing you are using if you can. You could also have it hooked up wrong.
If you have the pcv in the valve cover there needs to me a baffle under the valve to filter out the oil. Or you will have to have the valve in the rear of the lifter valley pan and the return air in the valve cover.

Either way it would be helpfull to see your setup.

 

[jemarshall64]

I am at work and this was the only pic I could dig up right now. It is a few years old, but the pvc system has not been changed.

You can see the spark arrestor sticking up off of the valve cover, it is still there with a filter on it now. The pvc valve is attached to the valley pan bellow/behind the mixer. There is a short piece of hose from the valley pan and the pvc is stuck in the end of it. It then is attached to the intake mannifold behind the mixer, just below where the carb mount is. This is also where I have the vac advance and the vaccume to the propane lockoff hooked up to the tree also.

I will pick up a new pvc valve after woork tonight and take it for another quick run up the hill to see how it does before I load it on the trailer.

 

[FDChappie]

When the heads were installed, was sealant used on the rocker shaft bolts? Some of the bolts go into the intake ports. How long have the rebuilt heads been run on the truck?

 

[jemarshall64]

Yes the bolts were sealed. I religously went over the vlve train as per mm advisments. Complete tear down and cleaning, re-assymble and oil flow checks. Not 100% sure of milage since reb-build, was 05 or 06, several job, overseas deployment and constant build mode since, but thinking 2000 ish, but defanatley not more than 5000.

 

[FDChappie]

Ok, so it's been good for a long time and this just suddenly appeared. A shot of carb cleaner in the pcv and flame arrestor couldn't hurt.

I had the flame arrestor plug on my Scout a long time ago. When it did oil puked out of the dipstick all over the exhaust and made a huge smoke cloud. But that was under heavy load pulling a trailer up a grade.

The pathways for oil in the combustion chamber are pretty limited, past the rings or via the intake. If you remove the oil fill cap and place our hand over it to you get suction or blow-by. Also is there any oil buildup where the flame arrestor hose goes into the air cleaner? These could be indicative of worn rings.

 

[jemarshall64]

The spark arestor was recentley cleaned. I went to put a new pvc in and get it hooked up to the intake like it should be. After an indepth conversation at the parts store that no, it should be threaded, I finaly found someone that told me that what I had in my hand was not a pvc vlv, so it got cleaned, added a filter to it and put it back on . Didnt change the pvc then either, but thinking I should have now.

 

[FDChappie]

The pcv is located at the back of the lifter valley pan. Just clean it out with some carb cleaner and if it rattles use it. I'd give it about a 2% chance of working, if it doesn't time for a compression check. Any word on the blow-by questions?

 

[jemarshall64]

Will just pick up new pvc, only a couple $. Still at work, I work 12 hr rotating shifts, but will check it when I get home, about 1830ish by time I stop by parts store, and let you know then.

 

[Robert Kenney]

Fd this is a 196 so the pcv is under the intake manifold in the lifter cover.

 

[jemarshall64]

Nr1 on right.

 

[jemarshall64]

Comp
cyl 1 118
2 130
3 125
4 85

 

[jemarshall64]

Ok, sorry but hen I went to post up some of what I found yesterday I was using my phone and accidentally posted them to different thread, but this is what I found

there was a little bit of pressure puffing out of the oil fill cap, but not allot. Changed out pvc and then made two passes up and down the hill, when coasting down hill it would still start to get the burning oil smell to it and out out a little bit of smoke, then when you would tap the throttle, it would puff out a pretty good ball of smoke. It was not constant in this though, it would do it, then I would coast on engine and it would do it again, then the next time I would coast on engine it wouldn't do it at all, maybe two three time in a row, then it would start doing it again. After this I figured it wouldn't hurt to pull plugs for inspect and compression test.

 

[Robert Kenney]

I'll try and post my feelings later this evening.

Try this:
disconnect the pcv from the manifold tree and cap the tree port. Leave the pcv valve in place on the engine end don't plug the open end, and take her for a drive. Let us know what happens.
If it still smokes it is not the pcv. Could be oil drain back holes are blocked.