oil pressure drop once warmed up

Rattletrap · 06-10-2012, 02:20 PM

after about 20-30min of driving, aka when the oil finally gets heat in it. I have oil pressure drop.
starts out cold at 40ish and builds like it should to 60+ and as its driven the OP gets down to 20 and will build to 30 but you can start hearing the top end rattle.

I put a "new" pump on it but who knows.
I do not think it would be the o-ring since it does have pressure till it gets warmed up.

Thought was to replace pump and if that doesnt help then I guess i will have to rebuild, URGH!

bwelch · 06-10-2012, 03:03 PM

Is it a mechanical guage?

ShawnBoyMoody · 06-10-2012, 03:38 PM

Ugh. I hate LS oil pumps.

schardbody · 06-10-2012, 03:51 PM

iron block or aluminum?

its pretty common on the aluminum block motors, seems like most people say its the lifter bores heating/enlarging letting pressure bleed off.

i dont know, all LS motors make noise, if you hear one not making noise worry.....

jmd · 06-10-2012, 05:12 PM

is it a 6.0 that is stroked?

Rattletrap · 06-10-2012, 05:55 PM

junkyard 6.0 iron block with mechanical gauge.

Darryl Buckner · 06-10-2012, 06:17 PM

Fram oil filter??

Matts94Z28 · 06-10-2012, 06:21 PM

What filter and what oil is in it?

ShawnBoyMoody · 06-10-2012, 06:22 PM

This is why I didnt change my worn out timing chain. Gotta pull the pump to get the chain off and I didnt want to chance fooling with it with my bad luck. Maybe I could have made 375 HP if the chain wasn't worn out and retarding the cam 6-8 degrees lol.

Rattletrap · 06-10-2012, 06:48 PM

Oil is Mobile dino oil and AC filter (I think). New GM pump purchased in Aug. I have original pump. Going to see if its covered under warranty.

URGH

Matts94Z28 · 06-10-2012, 06:57 PM

Do you know the mileage on the motor? Could it be possible that the wrong weight oil is being used and the motor is just wore slap out? I have seen similar issues with the use of incorrect oil weight in combination with "loose" bearing tolerances. However, you wouldn't think that would an issue on a stock motor as long as it doesn't have 300k miles.

Rattletrap · 06-10-2012, 07:33 PM

Unknown mileage from a 2001 Silverado. 5w30 in it.

BigdaddyDupree · 06-10-2012, 07:36 PM

My 5.3 has perfect oil pressure and it doesent tap at all.

Rattletrap · 06-10-2012, 07:39 PM

Quote:

Originally Posted by BigdaddyDupree

My 5.3 has perfect oil pressure and it doesent tap at all.

the 6.0 in the 71 is quiet too. Love that thing!

ShawnBoyMoody · 06-10-2012, 08:57 PM

Quote:

Originally Posted by BigdaddyDupree

My current 5.3 has perfect oil pressure and it doesent tap at all.

Fixed it for you.

schardbody · 06-10-2012, 09:40 PM

the iron block motors are alot quieter, my quarter million mile 4.8 is silent, but my LS1 chings and changs like every other one (garbage lifters?). oil pressure is a separate issue than noise though.

BigdaddyDupree · 06-10-2012, 10:02 PM

my first one made some lifter noise so it seemed. when i pulled it apart it had all wiped out cam bearings

Rattletrap · 06-11-2012, 08:08 AM

Consensus is to put different oil pump on it and see??

BigdaddyDupree · 06-11-2012, 08:22 AM

Si

Rattletrap · 06-11-2012, 08:26 AM

Contacting Scoggin D where it was purchased in Aug 2011 to see if they will warranty it, if not I will purchase new one from some place.
Could put the original one in it and see, that would be 'free'.....

06-10-2012, 02:20 PM	#1
Rattletrap Senior Member Join Date: Jun 2008 Posts: 402	oil pressure drop once warmed up: Updated after about 20-30min of driving, aka when the oil finally gets heat in it. I have oil pressure drop. starts out cold at 40ish and builds like it should to 60+ and as its driven the OP gets down to 20 and will build to 30 but you can start hearing the top end rattle. I put a "new" pump on it but who knows. I do not think it would be the o-ring since it does have pressure till it gets warmed up. Thought was to replace pump and if that doesnt help then I guess i will have to rebuild, URGH! __________________ 71 C10 LWB 6.0/4l80e swap Last edited by Rattletrap; 06-16-2012 at 08:17 PM.

06-10-2012, 03:03 PM	#2
bwelch Senior Member Join Date: Aug 2009 Posts: 3,774	Is it a mechanical guage? __________________

06-10-2012, 03:38 PM	#3
ShawnBoyMoody Senior Member Join Date: Aug 2009 Location: In the lab.... Posts: 8,159	Ugh. I hate LS oil pumps. __________________ The Krusty Koupe "Luck favors the oblivious, and boy am I lucky!"

06-10-2012, 05:12 PM	#5
jmd Senior Member Join Date: May 2008 Posts: 3,177	is it a 6.0 that is stroked? __________________ Cadillac man

06-10-2012, 05:55 PM	#6
Rattletrap Senior Member Join Date: Jun 2008 Posts: 402	junkyard 6.0 iron block with mechanical gauge. __________________ 71 C10 LWB 6.0/4l80e swap

06-10-2012, 03:51 PM	#4
schardbody Senior Member Join Date: Sep 2008 Posts: 1,158	iron block or aluminum? its pretty common on the aluminum block motors, seems like most people say its the lifter bores heating/enlarging letting pressure bleed off. i dont know, all LS motors make noise, if you hear one not making noise worry.....

06-10-2012, 06:17 PM	#7
Darryl Buckner The Top Dog Join Date: Dec 2007 Posts: 2,318	Fram oil filter?? __________________ When the people fear the government, there is tyranny. When the government fears the people, there is liberty. Thomas Jefferson

06-10-2012, 06:21 PM	#8
Matts94Z28 Senior Member Join Date: Apr 2008 Location: Summerville Posts: 12,039	What filter and what oil is in it? __________________ Charleston Performance Solutions 4560 Rivers Ave. N. Charleston SC 29405 843-225-1142 https://www.facebook.com/CharlestonPerformanceSolutions www.facebook.com/Selepack

06-10-2012, 06:22 PM	#9
ShawnBoyMoody Senior Member Join Date: Aug 2009 Location: In the lab.... Posts: 8,159	This is why I didnt change my worn out timing chain. Gotta pull the pump to get the chain off and I didnt want to chance fooling with it with my bad luck. Maybe I could have made 375 HP if the chain wasn't worn out and retarding the cam 6-8 degrees lol. __________________ The Krusty Koupe "Luck favors the oblivious, and boy am I lucky!"

06-10-2012, 06:48 PM	#10
Rattletrap Senior Member Join Date: Jun 2008 Posts: 402	Oil is Mobile dino oil and AC filter (I think). New GM pump purchased in Aug. I have original pump. Going to see if its covered under warranty. URGH __________________ 71 C10 LWB 6.0/4l80e swap

06-10-2012, 06:57 PM	#11
Matts94Z28 Senior Member Join Date: Apr 2008 Location: Summerville Posts: 12,039	Do you know the mileage on the motor? Could it be possible that the wrong weight oil is being used and the motor is just wore slap out? I have seen similar issues with the use of incorrect oil weight in combination with "loose" bearing tolerances. However, you wouldn't think that would an issue on a stock motor as long as it doesn't have 300k miles. __________________ Charleston Performance Solutions 4560 Rivers Ave. N. Charleston SC 29405 843-225-1142 https://www.facebook.com/CharlestonPerformanceSolutions www.facebook.com/Selepack

06-10-2012, 07:33 PM	#12
Rattletrap Senior Member Join Date: Jun 2008 Posts: 402	Unknown mileage from a 2001 Silverado. 5w30 in it. __________________ 71 C10 LWB 6.0/4l80e swap

06-10-2012, 07:36 PM	#13
BigdaddyDupree Senior Member Join Date: Jul 2008 Location: MACEDONIA Posts: 4,967	My 5.3 has perfect oil pressure and it doesent tap at all. __________________ . What you wanna do?

06-10-2012, 09:40 PM	#16
schardbody Senior Member Join Date: Sep 2008 Posts: 1,158	the iron block motors are alot quieter, my quarter million mile 4.8 is silent, but my LS1 chings and changs like every other one (garbage lifters?). oil pressure is a separate issue than noise though.

06-10-2012, 10:02 PM	#17
BigdaddyDupree Senior Member Join Date: Jul 2008 Location: MACEDONIA Posts: 4,967	my first one made some lifter noise so it seemed. when i pulled it apart it had all wiped out cam bearings __________________ . What you wanna do?

06-11-2012, 08:08 AM	#18
Rattletrap Senior Member Join Date: Jun 2008 Posts: 402	Consensus is to put different oil pump on it and see?? __________________ 71 C10 LWB 6.0/4l80e swap

06-11-2012, 08:22 AM	#19
BigdaddyDupree Senior Member Join Date: Jul 2008 Location: MACEDONIA Posts: 4,967	Si __________________ . What you wanna do?

06-11-2012, 08:26 AM	#20
Rattletrap Senior Member Join Date: Jun 2008 Posts: 402	Contacting Scoggin D where it was purchased in Aug 2011 to see if they will warranty it, if not I will purchase new one from some place. Could put the original one in it and see, that would be 'free'..... __________________ 71 C10 LWB 6.0/4l80e swap