new 350 has oil comming out breather cap - The 1947 - Present Chevrolet & GMC Truck Message Board Network

ibjoker69 · 08-05-2002, 11:22 PM

My new 350 has a pcv on one valve on one side and a oil breather cap on the other. Oil is blowwing out the breather cap. Should I have a breather with a air vent on this going into the air cleaner to fix this? Or should this be a closed system with just an oil filler cap? Thanks in advance for the advice, Joker69

O'l Buck · 08-05-2002, 11:31 PM

sounds to me like your pcv valve is plugged or not functioning properly

mikep · 08-06-2002, 12:35 AM

If you are getting excessive blow by it will do that of course. could be caused by a number of things. engine problems, rings not seated properly, improper gapping etc. Tell us more about the build. any problems? Did you gap the rings etc. I bought a car once that had been assembled with standard bore rings into .040" over bores and that was from a reputable rebuilder so anything is possible. How many miles on it?

A closed system really only works on small cubic inch engines. Especially if you have a blow by problem it wont work wth your engine. You'll just blow the PCV valve out of the valve cover. Make sure the PCV valve is OK but my guess is you put a new one in when you installed the motor right. Also check the line to the valve and make sure its not kinked. what sort of valve covers . If the PCV valve is slapped up against the breather baffle it wont draw crankcase gasses. Ive seen all this stuff happen.

ibjoker69 · 08-06-2002, 12:51 AM

It is a brand new motor form GMC with maybe 2000 miles on it. And the valve covers are tall edelbrocks ect... and yes I did put a new pcv valve in. Joker69

*67Fleetsidedream* · 08-06-2002, 07:10 AM

Do a compression test on each cylinder. Is oil coming out your dip stick tube? If not then it is not blow by.
Ben

JimKshortstep4x4 · 08-06-2002, 07:44 AM

Do your Edlebrock valve covers have baffles in them? There is a lot of oil in an overhead and if the bafflling is not there, oil will come out.

Jim

shortbed70 · 08-06-2002, 10:17 PM

Ita alittle late but my motor has tall circle track valve covers (2 breathers on one side) and I have what I thought was blowby but I have no oil coming out of my dipstick hole. What is this from then?

Blazer1970 · 08-07-2002, 07:52 AM

As Jim says, if your valve covers don't have baffles under the breather / PCV holes like the factory ones do, it is common for one of the pushrods to squirt oil right into the breather.

junkyardjohn · 08-07-2002, 01:44 PM

IF YOU HAVE A HIGH VOLUME, OR A HIGH VOLUME HIGH PRESSURE OIL PUMP, IT'S NOT UNCOMMON TO HAVE A SMALL AMOUNT OF OIL ESCAPING AROND YOUR BREATHERS AND FILLER CAP. ESPECIALLY IF THEY ARE THE PUSH-IN TYPE.

08-05-2002, 11:22 PM	#1
ibjoker69 hahaha Join Date: Jan 2002 Location: Bakersfield, Ca USA Posts: 131	new 350 has oil comming out breather cap My new 350 has a pcv on one valve on one side and a oil breather cap on the other. Oil is blowwing out the breather cap. Should I have a breather with a air vent on this going into the air cleaner to fix this? Or should this be a closed system with just an oil filler cap? Thanks in advance for the advice, Joker69 __________________ 69lwb, 29 A coupe hotrod, 55 chevy hardtop,

08-05-2002, 11:31 PM	#2
O'l Buck Recovering Truck Driver Join Date: Mar 2002 Location: Orleans, NE USA Posts: 1,883	sounds to me like your pcv valve is plugged or not functioning properly __________________ 67 K-20 350, SM465, Eaton rear, 4.56 no spin option 00 Dodge 2500 4x4, 24V cummins, 5 speed Chad South Central Nebraska

08-06-2002, 12:35 AM	#3
mikep Used to have a truck Join Date: May 2002 Location: port orchard WA Posts: 1,552	If you are getting excessive blow by it will do that of course. could be caused by a number of things. engine problems, rings not seated properly, improper gapping etc. Tell us more about the build. any problems? Did you gap the rings etc. I bought a car once that had been assembled with standard bore rings into .040" over bores and that was from a reputable rebuilder so anything is possible. How many miles on it? A closed system really only works on small cubic inch engines. Especially if you have a blow by problem it wont work wth your engine. You'll just blow the PCV valve out of the valve cover. Make sure the PCV valve is OK but my guess is you put a new one in when you installed the motor right. Also check the line to the valve and make sure its not kinked. what sort of valve covers . If the PCV valve is slapped up against the breather baffle it wont draw crankcase gasses. Ive seen all this stuff happen. __________________ No truck :-(

08-06-2002, 12:51 AM	#4
ibjoker69 hahaha Join Date: Jan 2002 Location: Bakersfield, Ca USA Posts: 131	It is a brand new motor form GMC with maybe 2000 miles on it. And the valve covers are tall edelbrocks ect... and yes I did put a new pcv valve in. Joker69 __________________ 69lwb, 29 A coupe hotrod, 55 chevy hardtop,

08-06-2002, 10:17 PM	#7
shortbed70 Registered User Join Date: Mar 2002 Location: Forney TX Posts: 4,512	Ita alittle late but my motor has tall circle track valve covers (2 breathers on one side) and I have what I thought was blowby but I have no oil coming out of my dipstick hole. What is this from then? __________________ Troy 1965 Chevy Bagged,361 sbc,voodoo cam,1.5 full roller rockers,patriot 185cc vortec heads 2.02-1.60,vortec weiand polished intake,demon carb my truckhttp://67-72chevytrucks.com/vboard/s...d.php?t=332884 Big Red Dog build http://67-72chevytrucks.com/vboard/s...d.php?t=572274

08-06-2002, 07:10 AM	#5
67Fleetsidedream Wiseass secured himself a BAN Join Date: Nov 2000 Location: MOON!!! Posts: 2,282	Do a compression test on each cylinder. Is oil coming out your dip stick tube? If not then it is not blow by. Ben

08-06-2002, 07:44 AM	#6
JimKshortstep4x4 Senior Member Join Date: Jul 2001 Location: Muskegon,MI,USA Posts: 6,026	Do your Edlebrock valve covers have baffles in them? There is a lot of oil in an overhead and if the bafflling is not there, oil will come out. Jim

08-07-2002, 07:52 AM	#8
Blazer1970 Registered User Join Date: Dec 1999 Location: Old Mission, MI, USA Posts: 2,507	As Jim says, if your valve covers don't have baffles under the breather / PCV holes like the factory ones do, it is common for one of the pushrods to squirt oil right into the breather. __________________ Tim

08-07-2002, 01:44 PM	#9
junkyardjohn Registered User Join Date: Aug 2001 Location: SOMERSET KY. Posts: 6,425	IF YOU HAVE A HIGH VOLUME, OR A HIGH VOLUME HIGH PRESSURE OIL PUMP, IT'S NOT UNCOMMON TO HAVE A SMALL AMOUNT OF OIL ESCAPING AROND YOUR BREATHERS AND FILLER CAP. ESPECIALLY IF THEY ARE THE PUSH-IN TYPE. __________________ junkyardjohn 69 1 TON TOW TRUCK // 84 4WD CUCV BLAZER// 85 1 TON 4WD STAKE TRUCK// 86 M1031 5/4 TON 4WD CUCV// ALOT OF OLD TRUCKS FOR ONE OLD MAN TO DRIVE. THERES ROOM FOR ALL OF GODS CREATURES RIGHT NEXT TO MY MASHED POTATOES// LIFE MEMBER OF P.E.T.A (PEOPLE EATING TASTY ANIMALS) DON'T RENT U-HAUL ALWAYS TELL THE TRUTH IT WILL AMAZE PART OF THE PEOPLE & ASTONISH THE REST



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