I am back and with problems - The 1947 - Present Chevrolet & GMC Truck Message Board Network

WORNBRAKES · 09-01-2002, 01:37 AM

Well it has been a month since I last posted. The 3000 mile trip across the country is over and we are settled here in Pensacola, FL. But that did not come without engine problems. I know I burned up my valve guides. There is a little smoke coming out my breather on the valve covers. I think that either my oil pump is going bad or I have worn rod bearings. Oil pressure is fine while I am driveng but when I slow down at a stop light, oil pressure drops. I know some of you have had this problem before, what was you cause? Any pointers would be great.
Thanks,
Mario

nu2-72 · 09-01-2002, 09:42 AM

Good to see you back. Oil pressure depends on the drop. Most Chevys are designed to build pressure of 10 lbs per 1000 rpm's. Meaning if your idle is 30 on a fresh engine at 800 rpm's, it would be around 50 at 2800 or highway speed. If it drops below 10 lbs at idle, I would look at some work very soon. Some drop is normal.

da-burb · 09-01-2002, 10:35 AM

smoke out the breathers is usually blow-by. Your rings no longer seal the combustion chamber. Pull your breather cap and your PCV valve, run the engine up in rpms and watch the valve cover openings. If it is blowing smoke like a chimney, it's rings.

6869704X4 · 09-01-2002, 10:52 AM

How you liking Fla so far? That make three members that I know of in this area.

greasemonkey · 09-01-2002, 10:57 AM

Where do you live 6869704x4? By the why Wornbrakes, that's the problem I have with mine too, blowby. At least that's what it sounds like yours has, mine blows clouds all over when I pull the PCV valve.

6869704X4 · 09-01-2002, 11:43 AM

Make that four members. Im in Navarre.
WORNBRAKES, I meant to ask you how much your pressure drops at idle. 10psi per 1000 rpm is minimum. Also, what wieght oil are you running? Here is a good source of info.
http://www.melling.com/techbul1.html

tom hand · 09-01-2002, 12:07 PM

I love this 10 psi per 1000 rpm rule except for one thing, a stock chevy oil pump won't do it. On a stock chevy oil pump the pressure relief spring is set at 40 psi, it won't go any higher. Most chevys I have seen that the oil pump has not been modified run 10-20 psi at idle and 40 psi cruzing. The tempature the engine is running at will play a major part in what the pressure is at idle, the hotter the motor the lower the idle pressure will be. Also don't trust the stock gauge, if you want to know what your oil pressure is, hook up a quality gauge.

WORNBRAKES · 09-01-2002, 09:47 PM

I am still using the fossile guage that came with the truck. Before the trip, I would always run at 3/4. Sometimes it would drop a little but not much. Now while I am driving, I am at 3/4 but when I slow for a stop light it slowely dropes to 1/4. On the way here it did it a few times but I was leaking oil so I can see a problem with pressure then. I have fixed the oil leak since and still have this problem. As far as the area members, I believe cyco path is in Robertsdale, AL. Not to far from here. We should all get together some time. Anyone going to the Super Chevy Show in Montgomery this month? The wife and I are planning on it.

nu2-72 · 09-01-2002, 10:33 PM

My stock pump pushes 55-60 all day long on a quality gauge and has for 141,000 miles. Quaker State 10-40

O'l Buck · 09-02-2002, 12:27 AM

try some 50wt synthetic

ChevLoRay · 09-02-2002, 07:05 AM

A heavier viscosity oil will help you get by until you can rebuild your engine....or just replace it with a crate motor. I had a '67 Impala convertible that did all yours is doing, plus when it got about a quart low, and I was in a curve on an off-ramp, the oil light would flicker. So, you know it was running on borrowed time. When I sold it, three years later, it was still doing the same thing.

Since your weather is milder than some other areas, you should be able to run a 20w40 or 20w50 oil, non-synthetic, and have your engine survive for quite some time. As long as you keep oil in it, it will run. Barring any component failure, i.e., spun bearings or oil pump failure, you'll have time to build an engine that will be just what you want.

WORNBRAKES · 09-02-2002, 08:18 PM

Right now I am running streight 30w in there. Maby I will try some 20w40 or 20w50. I am planning on rebuilding the motor sometime this winter when it is cooler here. Right now the garage is too humid to work in there for longer than 30 min. Thanks for the feedback. I guess I will have to keep a closer tab on the motor than I have had to in the past.

09-01-2002, 01:37 AM	#1
WORNBRAKES Senior Member Join Date: Jul 2001 Location: Hughesville, MD Posts: 1,350	I am back and with problems Well it has been a month since I last posted. The 3000 mile trip across the country is over and we are settled here in Pensacola, FL. But that did not come without engine problems. I know I burned up my valve guides. There is a little smoke coming out my breather on the valve covers. I think that either my oil pump is going bad or I have worn rod bearings. Oil pressure is fine while I am driveng but when I slow down at a stop light, oil pressure drops. I know some of you have had this problem before, what was you cause? Any pointers would be great. Thanks, Mario __________________ Mario and Mandy Hughesville, MD 20637 69 C10 305/350 71 K5 Basket case 75 K10 Rescue Parting out 77 MG Midget Parting out 15 6.7L Cummins

09-01-2002, 09:42 AM	#2
nu2-72 Senior Member Join Date: Apr 2001 Location: Amazonia, Mo. USA Posts: 2,821	Good to see you back. Oil pressure depends on the drop. Most Chevys are designed to build pressure of 10 lbs per 1000 rpm's. Meaning if your idle is 30 on a fresh engine at 800 rpm's, it would be around 50 at 2800 or highway speed. If it drops below 10 lbs at idle, I would look at some work very soon. Some drop is normal. __________________ 72 3/4 4x4 350 4spd 72 3/4 4x4 350 auto 2004 Duramax Silverado 4x4 2006 Duramax Crew cab 4x4 2010 Harley Ultra Limited 2011 Harley Street Glide

09-01-2002, 10:35 AM	#3
da-burb "Ochre Ogre" Join Date: Apr 2000 Location: Springfield, MN Posts: 3,558	smoke out the breathers is usually blow-by. Your rings no longer seal the combustion chamber. Pull your breather cap and your PCV valve, run the engine up in rpms and watch the valve cover openings. If it is blowing smoke like a chimney, it's rings. __________________ Bowtie Truck Stop Inc. Mid-West GM Truck Restoration Parts Supplier Your Key Parts, Auto Metal Direct, Dynacorn, and Goodmark dealer. like us @ www.facebook.com/BowtieTruckStop 1971 C-10 Suburban (Ochre) 1971 K-10 Suburban (Ochre) 1972 C-10 Suburban (Ochre) 1972 K-20 Suburban (Yellow- that just aint right!) Springfield, Minnesota 56087

09-01-2002, 10:52 AM	#4
6869704X4 Registered User Join Date: Jul 2002 Location: SE NM Posts: 769	How you liking Fla so far? That make three members that I know of in this area. __________________ The more I learn about women, the more I love my truck.

09-01-2002, 10:57 AM	#5
greasemonkey Registered User Join Date: Dec 2001 Location: Pace, FL Posts: 2,155	Where do you live 6869704x4? By the why Wornbrakes, that's the problem I have with mine too, blowby. At least that's what it sounds like yours has, mine blows clouds all over when I pull the PCV valve. __________________ 1942 Master Deluxe 1969 C/10 1985 Blazer CUCV 1987 Jimmy 2004 Tahoe 2005 Silverado 1500 2005 Silverado 3500

09-01-2002, 11:43 AM	#6
6869704X4 Registered User Join Date: Jul 2002 Location: SE NM Posts: 769	Make that four members. Im in Navarre. WORNBRAKES, I meant to ask you how much your pressure drops at idle. 10psi per 1000 rpm is minimum. Also, what wieght oil are you running? Here is a good source of info. http://www.melling.com/techbul1.html __________________ The more I learn about women, the more I love my truck.

09-01-2002, 12:07 PM	#7
tom hand CCRider Join Date: Feb 2000 Location: Olive Branch,MS,USA Posts: 2,232	I love this 10 psi per 1000 rpm rule except for one thing, a stock chevy oil pump won't do it. On a stock chevy oil pump the pressure relief spring is set at 40 psi, it won't go any higher. Most chevys I have seen that the oil pump has not been modified run 10-20 psi at idle and 40 psi cruzing. The tempature the engine is running at will play a major part in what the pressure is at idle, the hotter the motor the lower the idle pressure will be. Also don't trust the stock gauge, if you want to know what your oil pressure is, hook up a quality gauge. __________________ 72 GMC Sierra SWB almost finished---- 84 Softail Olive Branch MS

09-01-2002, 09:47 PM	#8
WORNBRAKES Senior Member Join Date: Jul 2001 Location: Hughesville, MD Posts: 1,350	I am still using the fossile guage that came with the truck. Before the trip, I would always run at 3/4. Sometimes it would drop a little but not much. Now while I am driving, I am at 3/4 but when I slow for a stop light it slowely dropes to 1/4. On the way here it did it a few times but I was leaking oil so I can see a problem with pressure then. I have fixed the oil leak since and still have this problem. As far as the area members, I believe cyco path is in Robertsdale, AL. Not to far from here. We should all get together some time. Anyone going to the Super Chevy Show in Montgomery this month? The wife and I are planning on it. __________________ Mario and Mandy Hughesville, MD 20637 69 C10 305/350 71 K5 Basket case 75 K10 Rescue Parting out 77 MG Midget Parting out 15 6.7L Cummins

09-01-2002, 10:33 PM	#9
nu2-72 Senior Member Join Date: Apr 2001 Location: Amazonia, Mo. USA Posts: 2,821	My stock pump pushes 55-60 all day long on a quality gauge and has for 141,000 miles. Quaker State 10-40 __________________ 72 3/4 4x4 350 4spd 72 3/4 4x4 350 auto 2004 Duramax Silverado 4x4 2006 Duramax Crew cab 4x4 2010 Harley Ultra Limited 2011 Harley Street Glide

09-02-2002, 12:27 AM	#10
O'l Buck Recovering Truck Driver Join Date: Mar 2002 Location: Orleans, NE USA Posts: 1,883	try some 50wt synthetic __________________ 67 K-20 350, SM465, Eaton rear, 4.56 no spin option 00 Dodge 2500 4x4, 24V cummins, 5 speed Chad South Central Nebraska

09-02-2002, 07:05 AM	#11
ChevLoRay Old Skool Club Join Date: Jun 2001 Location: Benton, AR "The Heart of Arkansas" Posts: 10,880	A heavier viscosity oil will help you get by until you can rebuild your engine....or just replace it with a crate motor. I had a '67 Impala convertible that did all yours is doing, plus when it got about a quart low, and I was in a curve on an off-ramp, the oil light would flicker. So, you know it was running on borrowed time. When I sold it, three years later, it was still doing the same thing. Since your weather is milder than some other areas, you should be able to run a 20w40 or 20w50 oil, non-synthetic, and have your engine survive for quite some time. As long as you keep oil in it, it will run. Barring any component failure, i.e., spun bearings or oil pump failure, you'll have time to build an engine that will be just what you want. __________________ Member Nr. 2770 '96 GMC Sportside; 4.3/SLT - Daily driven....constantly needs washed. '69 C-10 SWB; 350/TH400 - in limbo The older I get, the better I was.

09-02-2002, 08:18 PM	#12
WORNBRAKES Senior Member Join Date: Jul 2001 Location: Hughesville, MD Posts: 1,350	Right now I am running streight 30w in there. Maby I will try some 20w40 or 20w50. I am planning on rebuilding the motor sometime this winter when it is cooler here. Right now the garage is too humid to work in there for longer than 30 min. Thanks for the feedback. I guess I will have to keep a closer tab on the motor than I have had to in the past. __________________ Mario and Mandy Hughesville, MD 20637 69 C10 305/350 71 K5 Basket case 75 K10 Rescue Parting out 77 MG Midget Parting out 15 6.7L Cummins

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