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67 Chevelle Malibu (Convertible)
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Discussion Starter · #1 ·
Hey guys, What should my oil pressure be reading at idle? The needle shows no pressure at idle but when I rev the pressure matches the RPM.
 

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10 psi per 1000 rpm! Do you have a manual gauge to install to check the pressure??
 

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67 Chevelle Malibu (Convertible)
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Discussion Starter · #3 ·
10 psi per 1000 rpm! Do you have a manual gauge to install to check the pressure??
My gauge is manual, but I idle at 400-500 RPM, I guess maybe it is correct my gauge starts at 1000 RPM and there is a space before it goes to 0, the needle stays a little above 0.
 

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You might want to kick the idle up some. 700-750 rpm is about normal. On my built engines, I bump it to about 900 rpm.

Little more rpm at idle will bump your oil pressure.
 

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Discussion Starter · #5 ·
You might want to kick the idle up some. 700-750 rpm is about normal. On my built engines, I bump it to about 900 rpm.

Little more rpm at idle will bump your oil pressure.
Thanks for your input, the reason I had it set so low was because when I shift from park to drive it really jerks the drive train, is that normal? It’s real smooth now when I shift.
 

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No it is not normal if it jerks at 650-750 rpm. Maybe your tach is wrong or you have a broken motor or tranny mount. Few motors will run at 400-500 rpms without stalling especially if that is a neutral rpm. I would find oil pressure under 15lbs at idle concerning, Do you know what oil pump you are using, standard, high volume or high pressure?
 

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Discussion Starter · #7 ·
No it is not normal if it jerks at 650-750 rpm. Maybe your tach is wrong or you have a broken motor or tranny mount. Few motors will run at 400-500 rpms without stalling especially if that is a neutral rpm. I would find oil pressure under 15lbs at idle concerning, Do you know what oil pump you are using, standard, high volume or high pressure?
I’m pretty sure my RPM is correct, I will turn up my idle a little and see what happens. Thanks
 

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Discussion Starter · #8 ·
I’m pretty sure my RPM is correct, I will turn up my idle a little and see what happens. Thanks
Standard stock oil pump, turned the idle up to 750 but it fluctuates between 750 and 650 in park and drops to around 550 to 500 in drive. The oil pressure is reading 15-10lb in drive idle. When I take the shifter from park to reverse the motor lifts on the pass side and jerks a little but when I shift from neutral to drive is shifts smooth no jerk.
 

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Ryan
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What weight oil? Is this reading cold? Or warm? What engine? How many miles? If new, do you know the clearances? A little more info and we might be able to help a little bit more.
 

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Discussion Starter · #10 ·
What weight oil? Is this reading cold? Or warm? What engine? How many miles? If new, do you know the clearances? A little more info and we might be able to help a little bit more.
10w40 Penn
Reading warm
327
Rebuild 28 years ago
Maybe 50k miles
 

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Ryan
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10w40 Penn
Reading warm
327
Rebuild 28 years ago
Maybe 50k miles
I would think 40w would register a little more. Maybe those bearing clearances have opened up quite a bit since the rebuild. Has the pressure always been low? Or did it used to be higher? If it used to be higher, had the pressure gradually dropped, or was it a sudden decrease?

I just went back and read through the posts. What is your pressure while driving? If it’s a little on the low side also, maybe the clearances have opened up over time. 20w50 might be worth a shot.
 

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Discussion Starter · #12 ·
I would think 40w would register a little more. Maybe those bearing clearances have opened up quite a bit since the rebuild. Has the pressure always been low? Or did it used to be higher? If it used to be higher, had the pressure gradually dropped, or was it a sudden decrease?

I just went back and read through the posts. What is your pressure while driving? If it’s a little on the low side also, maybe the clearances have opened up over time. 20w50 might be worth a shot.
It’s around 10lb per 1000 RPM when driving but will drop below 5lb and lower at a stop sometime, not all the time. I installed a new gauge with copper line but no change. The engine seems to run fine just don’t like looking down and seeing little or no pressure.

Is it normal for the engine to shift up on pass side when shifting from park to reverse, and the drive train to jerk in gear at 750 RPM idle?
 

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1968 Malibu sport coupe, 489 ci. 590 hp 600 tq, RV T-400 Freakshow 3200 stall, 3.73 12 bolt posi
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I'd look close at the motor mount while someone else shifts the gear shift slowly back & forth with the E brake on, maybe have a mechanic take a look, and possibly switch to 20w50 oil like said, I use to do that with older HFT cam motors that had low oil psi do get it higher
 

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Ryan
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I’d try the 20w50 in this instance.

As for the jerking etc...
I would inspect engine and trans mount.
 
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Discussion Starter · #16 · (Edited by Moderator)
Looks like you have 1 or 2 broken motor mounts. Replace those and turn up your idle to 700 in drive.
Okay…no broken motor or trans mount👍🏻The strangest thing when I increased my RPM the motor doesn’t jerk like it did. I had someone give her gas with the E brake on and peddle brake while in drive, I got under the car and shined flash light on both motor mounts, you could see pressure on the mounts but they did not raise up.
I’m set at:
Park 1200 RPM - 22 PSI
Drive 700 RPM - 12 PSI
This is the engine hot at 180*
 

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That's a big drop in RPM from Park to Drive. Id check your timing both in Park and Drive (mech and vac. adv. settings), any vacuum lines for leaks (full or ported vac?) and pending Carb, reverify Idle Mixture Screws are set the same using a VAC Gauge.

Mike
 

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Discussion Starter · #18 ·
That's a big drop in RPM from Park to Drive. Id check your timing both in Park and Drive (mech and vac. adv. settings), any vacuum lines for leaks (full or ported vac?) and pending Carb, reverify Idle Mixture Screws are set the same using a VAC Gauge.

Mike
Seems to be running fine, just took her on a 20 mile run. If my RPM in drive is at 700 the way I want it, what should my RPM in park be?
 

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My Goodwrench 350 is about 750ish in neutral, and about 650 in drive.

Sent from my HD1907 using Tapatalk
 

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Discussion Starter · #20 ·
My Goodwrench 350 is about 750ish in neutral, and about 650 in drive.

Sent from my HD1907 using Tapatalk
Okay I missed around with the timing, N 800-900 D 650-700 sounds good, idles good, drives good...do y’all think I’m okay with that??? And my oil PSI is reading about 10 pre 1000.
 
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