Gauge problem? Bad oil pump? ??????? - The 1947 - Present Chevrolet & GMC Truck Message Board Network

BADPURPLE70CHEVY · 04-30-2010, 12:09 PM

Got the 406 in my truck and it will scream, but oil pressure gauge registers around 5-10 pounds of pressure at idle. I used all good parts but am wondering if it could be the gauge. Got a white face sunpro gauge. When your cruising the pressure is up around 40-50. No engine noise but is it possible the new oil puimp could be bad? Or cheap oil pressure gauge?

cdowns · 04-30-2010, 12:27 PM

electric or mechanical?? if electric it could be bad battery,charging system or wire connections

BADPURPLE70CHEVY · 04-30-2010, 12:32 PM

Mechanical......

Leviticus · 04-30-2010, 01:46 PM

What is your idle set at? My 350 will push about 22-28 psi at idle, 50 psi at cruise and 60 at wot. If your idle is set really low it could be giving you your low numbers.

I have my idle set at about 850 rpm's in park and that puts me at about 650 rpm's in gear.

Unless you have a leak in your gauge line, these mechanical gauges are pretty close to right. Also, I have never been one of those guys that has been a big believer in synthetic oils except in my diesel trucks. But odd as it is I gained about 5-8 psi at idle when I switched to a good syn...who knows?

BADPURPLE70CHEVY · 04-30-2010, 02:44 PM

Quote:

Originally Posted by Leviticus

What is your idle set at? My 350 will push about 22-28 psi at idle, 50 psi at cruise and 60 at wot. If your idle is set really low it could be giving you your low numbers.

I have my idle set at about 850 rpm's in park and that puts me at about 650 rpm's in gear.

Unless you have a leak in your gauge line, these mechanical gauges are pretty close to right. Also, I have never been one of those guys that has been a big believer in synthetic oils except in my diesel trucks. But odd as it is I gained about 5-8 psi at idle when I switched to a good syn...who knows?

My oil pressure is way lower so i gotta do some diggin into it to find the problem.

junkyardjohn · 05-02-2010, 03:31 PM

A GOOD RULE OF THUMB IS 10 LBS OF OIL PRESSURE FOR EVERY 1000 RPMS.(BIG DIFFERENCE BETWEEN 5 & 10 lbs AT 1000 RPMS) I'VE HAD THAT SAME PROBLEM A TIME OR TWO. AFTER YOU RULE OUT THE GAUGE & PULL THE OIL PAN TO CHECK THE OIL PUMP,(A REAL PAIN.. BUT POSSIBLE) PULL A COUPLE OF MAIN CAPS & LOOK AT YOUR BEARINGS. IF THERES ANY COPPER SHOWING OR YOUR CRANK JOURNALS ARE GROOVED OR THE FINISH DOESN'T LOOK POLISHED, PULL IT IMMEDIATLY & FIX IT. IF YOU DO.. DON'T FORGET TO SWAB OUT & CLEAN THE OIL GALLYS OR YOU WILL BE DOING IT AGAIN IN ANOTHER 2000 MILES. DON'T ASK HOW I KNOW.

LETS JUST SAY ALL THOSE LITTLE BEARING PARTICULS HAVE TO GO SOMEWHERE. I LIKE TO USE A SHOTGUN OR RIFLE CLEANING ROD WITH A BRONZE BRUSH ON IT. I ALWAYS HOPE FOR THE BEST & EXPECT THE WORST.
GOOD LUCK WITH IT. JOHN

BADPURPLE70CHEVY · 05-02-2010, 03:48 PM

Thanks. I hope its just a bad gauge because everything is brand new. Anyone ever had a bad gauge even though it was new?

bigguy69 · 05-02-2010, 04:24 PM

yep. mine came from advance. sunpro i think. it was swapped for another set

junkyardjohn · 05-02-2010, 04:27 PM

Quote:

Originally Posted by badpurple70chevy

thanks. I hope its just a bad gauge because everything is brand new. Anyone ever had a bad gauge even though it was new?

i never have.. But i always check it first, & look for a kink in the line... But i've never been that lucky. (it only takes about 5 min.) i have a 454 crankshaft that i welded to a 8"rally & the other end to a 6" vice. It serves as a daily reminder not to trust anybodys word on motor work. High dollar vice stand that i've had for over 20 years. As you probably know.. The price of admission is very expensive to this hot rod hobby. Good luck bud. Hope its something small & cheap. John

Hubscrub · 05-02-2010, 04:32 PM

My 383 in my nova has always run oil pressure about the same numbers as you are running since it was built (me and dad built it) dad said that a sbc motor does fine at 5lb pressure idle and 30lb pressure going down the road thats fine (he was a mechanic for 30+ years and dirt track raced for years) so i trust his judgement, not saying your 406 is the same but just saying so maybe to sure your mind alittle

BADPURPLE70CHEVY · 05-02-2010, 04:42 PM

Quote:

Originally Posted by bigguy69

yep. mine came from advance. sunpro i think. it was swapped for another set

Was it the oil gauge? What did it do?

BADPURPLE70CHEVY · 05-02-2010, 04:43 PM

copper line...no kinks...

**JDL** · 05-02-2010, 05:32 PM

what oil filter do you have

Jacfourteen · 05-02-2010, 05:42 PM

What weight oil are you running? If you are running light oil the pressure will be lower. You lose a little power (less than 1%, so not much) running heavier but you will have more pressure. Of course this doesn't mean that you want to run the heaviest oil you can get, but I'd ask an engine builder that you trust what they recommend for your build. My engine builder recommended that I run 20-50 because of the summer heat we get (110+).

bigguy69 · 05-02-2010, 05:45 PM

Quote:

Originally Posted by BADPURPLE70CHEVY

Was it the oil gauge? What did it do?

nothing. hooked up and nothing. i dont what was wrong with but the next was fine.

BADPURPLE70CHEVY · 05-02-2010, 05:52 PM

Quote:

Originally Posted by JDL

what oil filter do you have

Thought of that. running wix oil filter. Engine builder recommended 15/40 rotella. My brother runs 15/40 in a 700 h.p. dragcar with no problems. Might change the oil filter even though its new.

**truckdude239** · 05-02-2010, 08:12 PM

wix is a good filter dont think your problem is there your pressures sound normal to me 10 psui at idle and it should increase about 10 psi for every 1000 rpms

extd56 · 05-02-2010, 11:45 PM

Sounds Ok for me too, I have run motors with that oil pressure for a long time. AS long as the pressure goes up when you hit the throttle you should be fine. If the top end of your motor is not getting enough oil it will let you know when the rockers start to make noise.

04-30-2010, 12:09 PM	#1
BADPURPLE70CHEVY 406 Powered Join Date: Aug 2009 Location: waynesville,n.c. Posts: 877	Gauge problem? Bad oil pump? ??????? Got the 406 in my truck and it will scream, but oil pressure gauge registers around 5-10 pounds of pressure at idle. I used all good parts but am wondering if it could be the gauge. Got a white face sunpro gauge. When your cruising the pressure is up around 40-50. No engine noise but is it possible the new oil puimp could be bad? Or cheap oil pressure gauge? __________________ 70 GMC 68 c10 2002 silverado 72 4x4

04-30-2010, 12:27 PM	#2
cdowns Senior Member Join Date: Jan 2003 Location: daytonabeach Posts: 22,956	Re: Gauge problem? Bad oil pump? ??????? electric or mechanical?? if electric it could be bad battery,charging system or wire connections __________________ 71c-10 350/2004r/4:11 lowered3/4 longbed/dead by hurricane MEANING OF DEATH::::: SOMEBODY ELSE GETS YOUR STUFF DONT BELIEVE EVERYTHING YOU THINK TAKE MY ADVISE;I DON'T USE IT ANYWAY

04-30-2010, 12:32 PM	#3
BADPURPLE70CHEVY 406 Powered Join Date: Aug 2009 Location: waynesville,n.c. Posts: 877	Re: Gauge problem? Bad oil pump? ??????? Mechanical...... __________________ 70 GMC 68 c10 2002 silverado 72 4x4

04-30-2010, 01:46 PM	#4
Leviticus Shake and Bake! Join Date: Feb 2010 Location: Central Coast, CA Posts: 609	Re: Gauge problem? Bad oil pump? ??????? What is your idle set at? My 350 will push about 22-28 psi at idle, 50 psi at cruise and 60 at wot. If your idle is set really low it could be giving you your low numbers. I have my idle set at about 850 rpm's in park and that puts me at about 650 rpm's in gear. Unless you have a leak in your gauge line, these mechanical gauges are pretty close to right. Also, I have never been one of those guys that has been a big believer in synthetic oils except in my diesel trucks. But odd as it is I gained about 5-8 psi at idle when I switched to a good syn...who knows? __________________ "All tyranny needs to gain a foothold is for people of good conscience to remain silent." Thomas Jefferson "You are remembered for the rules you break." General Douglas MacArthur "Support Our Troops And The NRA"

05-02-2010, 03:31 PM	#6
junkyardjohn Registered User Join Date: Aug 2001 Location: SOMERSET KY. Posts: 6,425	Re: Gauge problem? Bad oil pump? ??????? A GOOD RULE OF THUMB IS 10 LBS OF OIL PRESSURE FOR EVERY 1000 RPMS.(BIG DIFFERENCE BETWEEN 5 & 10 lbs AT 1000 RPMS) I'VE HAD THAT SAME PROBLEM A TIME OR TWO. AFTER YOU RULE OUT THE GAUGE & PULL THE OIL PAN TO CHECK THE OIL PUMP,(A REAL PAIN.. BUT POSSIBLE) PULL A COUPLE OF MAIN CAPS & LOOK AT YOUR BEARINGS. IF THERES ANY COPPER SHOWING OR YOUR CRANK JOURNALS ARE GROOVED OR THE FINISH DOESN'T LOOK POLISHED, PULL IT IMMEDIATLY & FIX IT. IF YOU DO.. DON'T FORGET TO SWAB OUT & CLEAN THE OIL GALLYS OR YOU WILL BE DOING IT AGAIN IN ANOTHER 2000 MILES. DON'T ASK HOW I KNOW. LETS JUST SAY ALL THOSE LITTLE BEARING PARTICULS HAVE TO GO SOMEWHERE. I LIKE TO USE A SHOTGUN OR RIFLE CLEANING ROD WITH A BRONZE BRUSH ON IT. I ALWAYS HOPE FOR THE BEST & EXPECT THE WORST. GOOD LUCK WITH IT. JOHN __________________ 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 Last edited by junkyardjohn; 05-02-2010 at 03:36 PM.

05-02-2010, 03:48 PM	#7
BADPURPLE70CHEVY 406 Powered Join Date: Aug 2009 Location: waynesville,n.c. Posts: 877	Re: Gauge problem? Bad oil pump? ??????? Thanks. I hope its just a bad gauge because everything is brand new. Anyone ever had a bad gauge even though it was new? __________________ 70 GMC 68 c10 2002 silverado 72 4x4

05-02-2010, 04:24 PM	#8
bigguy69 dazed and confused Join Date: Jul 2008 Location: marion nc Posts: 1,649	Re: Gauge problem? Bad oil pump? ??????? yep. mine came from advance. sunpro i think. it was swapped for another set __________________ members met: redbaron69, billsbowtie,nc67

05-02-2010, 04:32 PM	#10
Hubscrub Cruzin Join Date: Dec 2009 Location: on the road Posts: 2,835	Re: Gauge problem? Bad oil pump? ??????? My 383 in my nova has always run oil pressure about the same numbers as you are running since it was built (me and dad built it) dad said that a sbc motor does fine at 5lb pressure idle and 30lb pressure going down the road thats fine (he was a mechanic for 30+ years and dirt track raced for years) so i trust his judgement, not saying your 406 is the same but just saying so maybe to sure your mind alittle __________________ Lime Wife's 67https://www.google.com/url?sa=t&rct=...wZEMODaS2d94u8 Back to the Fifties 59 https://www.google.com/url?sa=t&rct=...NAeStpydfrcj_U Proverbs 3:5,6 "Thanks to the Interstate Highway System, it is now possible to travel across the country from coast to coast without seeing anything."Charles Kuralt In memory of our first baby daughter, daddy and mommy love you. Danica Grace 6/26/14

05-02-2010, 04:43 PM	#12
BADPURPLE70CHEVY 406 Powered Join Date: Aug 2009 Location: waynesville,n.c. Posts: 877	Re: Gauge problem? Bad oil pump? ??????? copper line...no kinks... __________________ 70 GMC 68 c10 2002 silverado 72 4x4

05-02-2010, 05:32 PM	#13
JDL Senior Member Join Date: Sep 2000 Location: Agency IA. Posts: 1,884	Re: Gauge problem? Bad oil pump? ??????? what oil filter do you have __________________ 72 Chevy short step side with 454 air and tilt. 72 nova project car 63 chevy II drag car Agency Iowa

05-02-2010, 05:42 PM	#14
Jacfourteen Big Red - Now its a SWB! Join Date: Jun 2009 Location: Oroville, Ca Posts: 1,624	Re: Gauge problem? Bad oil pump? ??????? What weight oil are you running? If you are running light oil the pressure will be lower. You lose a little power (less than 1%, so not much) running heavier but you will have more pressure. Of course this doesn't mean that you want to run the heaviest oil you can get, but I'd ask an engine builder that you trust what they recommend for your build. My engine builder recommended that I run 20-50 because of the summer heat we get (110+). __________________ 68 3/4 ton (Project)-350 Small Block, .030 over, 10:1 comp, 3998993 heads, C3BX edelbrock intake, comp cams XE268, Holley 670 SA, long tube headers, dual flow 40's, E-fan, Alum rad, currently under the knife getting shortened and bagged build thread 41 3/4 ton (wife's)-flatbed, fully restored to original 01 Tahoe LT 4WD (my daily driver)-Magnaflow Muffler, Rollin on 22's 02 Ford Mustang Convertable (Wife's Car)-Flowmaster 50, Clear corners, Intake, sittin on 18's

05-02-2010, 08:12 PM	#17
truckdude239 Senior Member Join Date: Sep 2005 Location: Lewisville, Nc Posts: 10,238	Re: Gauge problem? Bad oil pump? ??????? wix is a good filter dont think your problem is there your pressures sound normal to me 10 psui at idle and it should increase about 10 psi for every 1000 rpms __________________ David fuller Ase Certified Mechanic Click here to help support our board!! 1971 Chevy c-10 under going a 4.8l LSx swap Build Thread http://67-72chevytrucks.com/vboard/s...d.php?t=421305 2007 Honda Accord my daily 145kmiles 2002 Honda Accord 4 door With 330k(sisters car) 2005 toyota Avalon 228k( brothers car) 2002 Sububran 5.3 245k 2000 Tahoe 5.3l 378 General manager for Marco's Carwash & lube

05-02-2010, 11:45 PM	#18
extd56 Senior Member Join Date: Nov 2004 Location: Vacaville, CA Posts: 2,272	Re: Gauge problem? Bad oil pump? ??????? Sounds Ok for me too, I have run motors with that oil pressure for a long time. AS long as the pressure goes up when you hit the throttle you should be fine. If the top end of your motor is not getting enough oil it will let you know when the rockers start to make noise.



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