Blue smoke. Now wtf?

[Mark1972]

Ok, so with over 1000 miles on the rebuilt 440, for the first time it was blowing blue smoke during warm up this morning. Not much, but enough I noticed. My wife and I went for a drive for lunch, and there was a trail of blue smoke behind us. We came home. I popped the hood and had a look around, but blue smoke is oil, so what am I going to look at. I did some research and decided to change the PCV valve, even though the one on the engine seems fine, and was basically new. Went for another drive, had some smoke coming from behind, and it eventually stopped. Got home in garage, revved it up and held it around 2500, and this time no smoke. Should I be looking further into this or was I right to guess PCV valve?

 

[1967coronet]

pull the plugs , look for oil.
if you was pushing oil past the rings with crank case pressure I would expect other oil leaks also. Unless you have a not seated yet oil ring on a piston that and some pressure would do it on a new rebuild.
pull the plugs 1st.

 

[Mark1972]

I have decided to do a compression test tomorrow as well, so I will be pulling the plugs and checking them. I didn't mention before, but there is a slight leak of engine oil at the rear main seal and at the front, around the timing cover or behind the balancer somewhere. I warned up the engine again a few minutes ago and checked the PCV vacuum at th port on the carb and it was 16in.

 

[turbine68rt]

Break out the vacuum tester and see what results you get.

 

[zyzzyx]

Oil usually comes from two places, Rings or valve seals. Good luck!

 

[PRND21]

What valve covers are you using? If they’re aftermarket with no baffling, then the PCV valve can easily suck oil into the intake.

 

[1 Wild R/T]

Intake gasket.... Put a wrench on the intake bolts....

 

[snakeoil24]

Blue equals misaligned ring on piston Choice 1, Cracked ring number 2 or bad and or stem seal went bad or did not seat leaving guide number 3 which shows at idle more than any time. Leak down test then Compression test. Pvc not likely.

 

[Mark1972]

What valve covers are you using? If they’re aftermarket with no baffling, then the PCV valve can easily suck oil into the intake.

The valve covers are the tin units sold on 440 Source. They have the baffle. Also, when I pulled the PCV valve, it was clean, and tested fine. I replaced it anyway. Thanks for the tip though. In a couple hours I'll post what the plugs looked like and what the compression numbers are.

 

[Daves69]

Read those plugs first.

 

[Mark1972]

Intake gasket.... Put a wrench on the intake bolts....

Checked them a few mins ago. All torqued to spec. None loose. Thanks for the tip. Much appreciated.

 

[Mark1972]

Read those plugs first.

This is the first one(cylinder 1). I'm not really sure what I should be looking for. If you can give me a few things to look for I'd appreciate it.

 

[1 Wild R/T]

The black around the edges is oil.... Do all eight have that?

I still say intake gaskets... I would pull the intake & check the fit all around with a feeler gauge...

Is it an aluminum intake? Have the heads or deck been milled?

Did you use any sealer on the intake gaskets?

 

[Mark1972]

It's an aluminum Performer RPM, and Edelbrock E-Street aluminum heads. I checked the intake bolts for looseness, but everything was good. Before I dig too far I'll have to speak to the engine builder first. Cylinders 3,2,4 have oil on the threads, 6 and 7 have some oil, but very little compared to 3,2, and 4. 1,5, and 8 are basically dry. The block was decked as part of the machinig process. Compression is supposed to be 10.1-1. After I changed the EGR valve last night and went for a drive, the smoke stopped. I pulled into the garage and held it at 2500-3000 for 30 seconds or so, and no smoke. Next up is the compression test. I'll post in a bit what I found.

 

[1 Wild R/T]

Honestly a compression test is useless for an oil consumption concern....

If the oil is going past the rings the oil will improve the sealing ability of the rings.... If the oil is going past the guides it won't have any effect on compression....

 

[Mark1972]

I'm a backyard guy with limited engine experience and tools. I just finished the compression test with my buddies tester, and here's what I got.
1)180
3)150
5)150
7)150
2)10
4)180
6)180
8)180

So I'm not exactly sure what the 150-180 difference means, but the 10psi in cylinder 2 is concerning. Any thoughts on next step? I'm calling the engine builder Monday morning. The only thing I can think of is if a friend has a bore scope, take a look in #2.

 

[Fran Blacker]

It could be residual oil from PVC and hasn't burned off yet. Might want to clean the hose from PVC to carb.. Clean plugs off and go for a ride. Edit: that 10 lbs I'd re cleck, real bad.

 

[1 Wild R/T]

I'm a backyard guy with limited engine experience and tools. I just finished the compression test with my buddies tester, and here's what I got.
1)180
3)150
5)150
7)150
2)10
4)180
6)180
8)180

So I'm not exactly sure what the 150-180 difference means, but the 10psi in cylinder 2 is concerning. Any thoughts on next step? I'm calling the engine builder Monday morning. The only thing I can think of is if a friend has a bore scope, take a look in #2.

Either your gauge acted up or a valve isn't sealing....
The shrader valve in the end of the gauge sometimes gets debris in it & doesn't seal....
With the oil residue in the chambers that is likely... Clean the tester & try again...

 

[zyzzyx]

Triple check the cylinder with the low reading, and then pull the valve cover and make sure the valves are opening
AND closing! If the numbers stay the same and the valve train is working correctly. pull the head on that side. If
everything looks good after that, It's time to pull the engine! Gulp!

 

[Fran Blacker]

I'd remove rockers as the last test before pulling head. Don't know if you'll get a good reading without intake valve opening maybe back off adjuster if you have adjustable rockers.