[birdboy68]

I have a 455 that uses 1 quart of oil every 80 miles. The motor only has aprox. 3000 miles. I have the pcv in the valley and going to the carb. I also have a breather in each valve cover with a hose from both going to the underside of my aircleaner. I got this idea from a forum, to reduce crankcase pressure. I used to have just one breather on the drivers side valve cover and pcv in the valley pan to the carb., and the breather would get loaded up with oil. I checked both hoses from the vave covers for oil and there is none. A friend of mine told me that it is sucking thru the carb.from these hoses, even though there is no oil residue. Is this true? The motor does smoke on start up and when get into the gas but not that bad. Any help would be appreciated

[SRR]

What weight oil are you using? Any leaks? An engine with 3000 miles should not smoke at all. What kind of head work was done? Can you post a picture of your set up?

[Murf'sDad]

Sounds like you don't have a baffle around your PCV and it is sucking oil out of the valley. It's not a stock valley pan, is it?

Stewart

[66bonne]

Same question as Murph'sDad - Is it an aftermarket valley pan ? If so it probably does not have a baffle and therefore will suck a lot of oil which will be dumped into the carb.
How do your spark plugs look ? From what you describe they should/could be very black and somewhat damp.
I have run hoses from valve covers to air cleaner but they did not pull enough vacuum for my motor. So I would not expect that you would find any oil in yours.
Before I finally figured out an effective PCV system for my car it would suck/blow out as much as a quart of oil after a night at the strip.
Thanks, Jim

[birdboy68]

Iam not sure if its a stock valley pan. I bought the motor as a whole about 4 years ago. The plugs look pretty good ,I pulled 3 plugs and they are brown to light brown and dry. There is a black color around the base of the plug. Iam using 5-20 castrol. no leaks accept for the notorious rear main drip. I have a list of what was done to the motor . I will have to locate it. I tried to take a picture of the plug but my camera cant focus that close. I pulled the pcv valve and saw some oil in it. I think the valley pan had a baffle, as when I put my finger in the hole it touch metal a couple inches down. this would indicate a stock pan. I tried to upload some pictures of the motor but it kept failing. any ideas

[66bonne]

Sounds to me like you have a stock valley pan. And your description of the spark plug color is right on. A little smoke at start-up is no big deal. Have someone follow you around and see if and when you get smoke out of the exhaust. When you park the car for awhile, throw a piece of clean cardboard under the engine and see if you have any leaks other than your rear main [mine leaks too].
Keep us posted.
Jim

["QUICK-SILVER"]

5-20 castrol? 20-50 castrol might cure it.

[birdboy68]

Iam sorry , I meant 20-50 ooops Iam using 20 -50

[DBONES152]

I'm following this thread because of a simmilar problem. Not a quart every 80 but maybe a quart every 150, even more if I'm really getting on the car. If it turns out that it is the PCV valve sucking oil due to no baffle, is there a solution short of replacing the valley pan?

[ELKHORNAOG7]

I would do a comp. test and a leak down test see what you come up with, these two test will tell you alot-----BOB

[66bonne]

DBONES: Try this to see if it helps - Take the hose off of the PCV valve in the valley pan. Get a "Chrysler" style valve cover mounted breather. This kind of breather has a tube coming out of it. Plug your hose into the breather. Keep an eye on the oil level.
Your valley pan PCV valve won't draw any oil since it is disconnected from vacuum.
Also, does the hose from your PCV valve plug into the carb, intake manifold, air cleaner or other vacuum source ?

Keep us posted, Jim

[66bonne]

It took me quite awhile and a lot of experimenting before I came up with a PCV system that was pretty effective for my Catalina with a 455. As stated above in another post we would loose as much as a quart of oil at the strip.
Here is what I did. Not saying that this is the only way to do it but maybe you can pick up something here that might work for you.
http://www.billetspecialties.com/ From Billet Specialties I got two valve cover breathers that had PCV valves mounted in them. I also stuffed these breathers with reuseable filter medium from Billet Spec. I ran a hose from each breather and used a "T" fitting to to take the hoses to the carb vacuum source. I then took my valve covers [from Butler Performance] and fabricated a baffle to go over the breather hole and mounted the baffles inside the valve cover. When reinstalling the valve covers I also installed a valve cover spacer.
Good luck, Jim

[303ta]

I also will watch this post, I have had this problem for almost 2000 miles on my 400.Last week I relaced my teflon valve seals with viton with no improvement. I think the next step is to lean out the carb as much as i can to see if the mixture is so rich its washing oil off the cylinder walls.

[Malky]

Brown spark plugs with today's gas is not normal, IMO. The centre electrode should be white and the ground strap white to grey. Black around the base is normal. If the brown is a baked-on residue, you are burning oil.
Also, smoking is not normal. Smoke at startup is usually valve stem guides and seals. Smoke when getting on it after backing off indicates bad ring seal.
So you may have a bad rebuild with sloppy guides, the wrong valve seals or no valve seals, bad hone job, etc.
Sorry to be so negative but a quart every 80 miles is terrible!

[Geoff]

My guess is the rings didn't seat & the bores are glazed. Symptoms are high oil consumption. Sometimes the dip stick will be pushed out at high rpms from the escaping presure past the rings.

PCV is easy to eliminate as the culprit: disconnect it & plug it. Drive for 80 miles. If it still uses a quart of oil, it ain't the PCV!

[HWYSTR455]

I agree, would have to say ring seal would be my first guess. Engine sat for 4 years before firing? Or it's just 4 years old? How many miles on it? And you say a drip from the rear main? Maybe it's a combo of things, rings, valve guides, and pvc. If your experiencing higher than usual crank pressure, it's rings. There's a couple things you can do that might help, but I'd say first post what's been done to the engine, might give a better clue...

[DBONES152]

66BONNE - The PCV hose goes directly to the carb.

MALKY - After a season of driving (1500 to 2000 miles) my plugs have a pretty good build up of brownish-tan residue on the ground strap.

I guess I'll try plugging the PCV valve to see if it helps and go from there.

Thanks,
Dan

[birdboy68]

Thanks for all the great advice. Theres alot of good theorys here and maybe a combination of all. The pcv is connected from the valley pan to the back of the carb. which is a 750 dbl pump demon. I also found out this motor was raced a few times with nitrous before I bought it. It smokes when accelerating, which is telling me rings. I will need to do a compression and leakdown. What effect will there be if I temp. block off the pcv valve. I still have the breathers going to the carb from each valve cover. thanks, derek

[sts]

Engine sat for 4 years before firing? Or it's just 4 years old?

What difference does that make? It's a Pontiac, not a chevy. Thest things can sit for 20 years without long storage prep without missing a blink.


Were a set of rings tossed into a "honed" not fresh bore? Maybe it's because I have always been around bad luck, but I have never seen anyone chunk a set of rings into an old bore with satisfsctory results. The only way I would install a set of rings would be in a fresh bore.

[birdboy68]

I think the problem might be the 750 demon is running to rich. I noticed my oil getting dark very quickly and thinning out, due to gas contamination. The gas is getting pas the ring and into the oil. I will rejet the carb and go from there. Thanks for all the input. This might not be the end.