My engine lets out smoke when I first shift into third and fourth gear and get on the throttle. Sometimes when I get on it it will pause then finally get up and go after a second in all gears. Engine doesn't smoke at startup and doesn't constantly smoke. It is a blue cloud and smells like oil. Engine is numbers matching so I'm done driving it until I fix the issue. Just put new exhaust on the car a lot bigger than the previous mufflers now has 3.5". Did not do this with the old pipes.

 

I would suggest two things. Do a cylinder pressure test and then do a cylinder leak down test. This will tell you about the condition of the rings and the valves. I have no idea if the exhaust change has caused any of your issue. For additional info, do a search here and you should find more info on the two tests. Dennis

 

:agree: But don't forget the simple first checks - Look at the air breather and see if there is a lot of oil film around the tube coming from the back of the block. Also remove the PVC valve and shake it, it should rattle. If it is oil, the new tail pipes should have an oily residue, not soot from an over rich carburetor. Of course, always look at the plugs to see what deposits they have on them.

 

You should still do the compression/leak down test even if there is a simple fix (doubtful) you'll then have a good snapshot of your engine health. Off the cuff, I think you're in for an overhaul...

I don't see how bigger exhaust system would cause this problem, even though it prob scavenges better with lower back pressure...

 

Great advice so far, compression and leak down tests will tell the condition of the rings and valves.
If the engine is original it could be as simple as bad valve seals. I wrote an article with pics on how to replace them, if you want a copy just PM me.
Joe

 

Took a look today. There's a puddle of oil on my intake and a puddle in the bottom of the air cleaner.

 

There is no oil going thru the intake, so it must be dripping from the air cleaner or coming from the valve covers. Valve cover leak will not go out the tail pipe. I would check the PCV valve, if it rattles (it is good), If it does not rattle, you might be lucky, replace it (or clean it if you wish) and try again. If it rattles, start pulling plugs, read them, and proceed with the compression and leak down test as Frankie recommended. You can never go wrong doing a compression and leak down as it is like an annual physical at the doctor for your engine. I don't think the valve guide seals, or guides would be the major problem that is giving you grief. Valve guides leak into the cylinder but should not increase crankcase pressure to blow it into the air cleaner.
How many miles on this motor?? What oil are you running?? Did you change from a petroleum based oil to a synthetic??
It is time for the professional mechanics to chime in and help you, I am just an OLD redneck wrencher, not a PRO.
Good Luck.

 

Just got done talking to a friend and we've come to the conclusion that it's a bad PCV valve which makes sense because I just put the elbow on the bottom of the filter and connected the tube from the crankcase breather as this was absent from my engine before. Also makes sense because with bigger exhaust it would be pulling more air through the the filter which was full of oil. Thank god it was only something minor but I figured it was because the engine was rebuilt in '83 and hasn't had a lot of miles put on it since then . Would this cause the engine to pause for a second when you get on the throttle then get up and go? Friend said it could be accelerator pump?

 

Odometer is broke 5000 miles on rebuild when bought in '83 and probably another 10000 since then. Running conventional oil.

 

Excess fuel through the accelerator pump can cause a bog, what carburetor, accelerator pump size and pump cam.

 

This is not necessarily a true statement. Generally speaking, it isn't correct.

If your PVC system is plumbed like OEM, you shouldn't have a puddle of oil in the air cleaner unless there's something wrong with the engine.

Sounds to me like your engine is sucking oil out of the crankcase because of either a defective PCV valve or some home made plumbing that isn't correct for the application.

The hesitation could be caused by a lean condition of a PCV valve that is stuck open causing a lean condition and also sucking the oil out of the crankcase.

 

Holley. 2818. Could the oil going through the carb cause it to bog like that? It's full of oil.

 

On an older engine, I've lowered the back pressure significantly ( your new exhaust?) and had oil consumption issues from the rings not sealing as well from the pressure change. Doesn't happen often. Sounds like you have a blow-by issue. Could be rings, pcv, or something else.

 

If the PCV valve is stuck open, I am guessing (not 100% sure) it would be a large vacuum leak and cause a rough idle and bog. The PCV is tied below the throttle plates (manifold vacuum). I am guessing this could cause a lean condition upon throttle coming off of idle and the accelerator pump can't supply enough fuel to compensate.
Clean everything up, change the PCV, and then see what happens. Better breathing through the new pipes didn't cause the blow by, just increased it due to less back pressure in the cylinders.
I am not convinced it is just the PCV valve, but have been wrong before. PCV valves generally get plugged closed and thus the blow by goes into the air cleaner. There should be a negative pressure in the crankcase to savage the oil fumes. If oil is puddled (not just a film) in the air breather, you have blow by.
As Dennis and Frankie have said, do the compression check and leak down test even if the problem goes away. I think you may still have some blow by, but some is acceptable as even new engines have some blow by. If this just started all at once and you find it is not the PCV valve, I would worry about a broken ring scoring the cylinder wall.
Hope the PCV cures it.

 

With the right levels of ZDDP ? Correct ?

 

10w 30 not sure what kind I'll have to ask him what he put in it.what do you use?

 

 

Shell Rotella is good. For synthetic Mobil 1 15-50 is good as well.

 

Who is he who puts the oil in??? How long between changes???

I don't know that I have the knowledge to help on this one.

 

Both are good suggestions - any CJ-4 rated oil will suffice but these old cars require ZDDP for lasting engine health. This additive has been removed from modern car oils for many years...ostensibly to preserve the catalytic convertors....

This is pretty important and you (OP) should get to the bottom of it soon