spewing oil out the breather?

[Anonymous]

I have about 2,000 miles on my re-build, everything has been going well but today it spewed oil out of the breather all over the place.

The pcv doesn't seem to be clogged.

When I pull the breather cap off while it's idling there is a pulsing puff of air that comes out that seems to be cycled with one of the cylinders. . . I don't remember that happening before.

Any ideas?

What does this sound like to you guys? Should I pull the valve cover and look for somethinbg in particular? Could exhaust be blowing past one of the valve seals. It feels like it has a bit less power too but that could be my imagination

 

[addo]

Run it until the thermo opens, and pull all the plugs. Do a compression test dry and wet on each bore (inject about a tablespoon of oil for the wet test). It sounds like blow-by to me.

 

[Anonymous]

Please explain what blow-by is.

Past the rings into the crankcase? Would one of the cylinders come up with lower compression? Particularly on the wet or dry test?

 

[addo]

Blow-by is combustion pressure leakage past the rings. A gauge that screws in the plug thread is way better than the push-in type with a rubber nozzle.

For oil to be ejected through the breather orifice suggests major leakage. The "wet" test in effect seals the rings a little more (temporarily), so is a good indicator of whether compression is being lost via the valve sealing, or piston-bore sealing. Depending on who you listen to, either >10 pounds increase or >10% increase when oiled up like this, is indicative of bore problems, including heavy wear.

When you pull the plugs out, take a moment to examine each (lay them in order).

There are other things that might cause significant blowby, but are probably less likely here. If you are able to, post some compression numbers for both wet and dry. Describe how the needle rises, too (big jumps or small steps).

Adam.

 

[66200i6]

I am particularly interested in whether or not the problem is coming from #1 and or #6. The more I look into how a torque/boring plate is made and why it is necessary, the more I am convinced this block needs one during boring.

I sure hope this is not the case with your block. Good luck and let us know what you find, Ric.

 

[Anonymous]

o.k. couldn't sleep much last night- I wonder why?

so i got up early and went and bought a compression guage-screw in type- and ran the test. Here is what I got-

#1- 200
#2- 200
#3- 200
#4- 195
#5- 200
#6- 80

I squirted some 10-40 in #6 and it didn't get any better.

So does that indicate a valve problem? Or is that cylinder so bad that even oil doesn't seal it?

What should I check next?

 

[Anonymous]

Sounds like you may have damaged your compression rings on the #6 cylinder. This entales removing the oil pan and crank to access the piston. This way you can re-ring the piston without removing the engine.

If you don't have a Chilton manual - get one! I had to special order my copy but it explains in detail this proceedure (without removing the engine).


-Chris

P.S. Wish I saw 180psi +

 

[Anonymous]

Or...just thought of this...sense your engine has very few miles on it, try re adjusting your rocker arms. You may just have a loss valve that is not seating completely.

Yes, check those valves before tearing down the motor again.


-Chris

 

[Anonymous]

I double checked the valves by loosening the rocker arm adjustment alot so that the valve spring puts full pressure for sure. . . still no change in the compression reading.

How do rings suddenly go bad? I have heard of them wearing out over time but this is a new assembly. Does this even happen?

What else could be wrong with the valve- do they ever crack, warp or break so they can't seal?

 

[BIGREDRASA]

Unfortunately this sounds more like FOD, foreign object damage. I speak from experience. Something has worn a groove on your cylinder wall, or you have a damaged piston. Better pull the head before you do any more damage.

 

[Junk-Falcon]

if your

 

[addo]

You should stop for a moment to be very pleased with the other cylinders. It's obviously otherwise a good engine.

That the compression didn't perceptibly change from 80 and that also there is the noticeable blow-by, suggests either a cracked piston or badly scored bore. Mild scoring (like from a busted scraper ring) will come up higher with oil in there.

Yes, you'll have to pull the head. But chances are, also the whole motor immediately following. For that reason, it'll pay to be prepared for the latter. If the bore is FUBAR, try sleeving it then light bore and hone. again, along the way play forensic. Look for sticking, scuffing or wear accentuation on all surfaces.

(The devil in me says just chop off the intake rocker arm on #6 and run it as a 5-cylinder!)

Adam.

 

[gtm1086]

Blown head gasket may also cause this.

 

[addo]

Only if it blew into the pushrod gallery.