Oil pump problem
Thread Starter
Intermediate
Joined: Apr 2019
Posts: 26
Likes: 6
From: Jacksonville
Oil pump problem
I had a small oil leak from the oil pan so I decided to replace the pan with a new gasket. I put the new one on along with a new oil pump. I figured I would replace it while I was under the car. I think I didn’t pull the oil pick line down enough because when I tried to start the engine it sounded bad so I immediately turned off the car.
I was able to use a wire to pull down the oil pick line to the bottom of the pan thinking it would solve the problem but the engine sounds horrible. It only ran for 2-4 seconds.
looking back I should have left the oil pump alone. Is it possible that the oil pump is bad? Did I do something wrong when I installed it?
I will have to repeat the repair but I may get a new oil pump again just in case. It was a pain for me to do this repair. Any advice would be appreciated.
I was able to use a wire to pull down the oil pick line to the bottom of the pan thinking it would solve the problem but the engine sounds horrible. It only ran for 2-4 seconds.
looking back I should have left the oil pump alone. Is it possible that the oil pump is bad? Did I do something wrong when I installed it?
I will have to repeat the repair but I may get a new oil pump again just in case. It was a pain for me to do this repair. Any advice would be appreciated.
2026 Loser of the Year
Joined: Sep 2013
Posts: 36,595
Likes: 7,043
From: New Or-leens Loo-z-anna
Rookie suggestion: always pour new oil into the pump and rotate the internal parts before bolting it in place.
Always measure the depth of the oil pan to make sure the pickup tube is long enough to reach the bottom of the pan after inserting the upper end of the tube into the oil pump (just in case)...tubes that are too short can gradually come out of the pump while the engine is running
Always check the oil level on the dipstick before cranking the engine.
ALWAYS disconnect the wiring plug from the distributor so the engine will NOT start.
Always crank the engine over about 5 seconds at a time until oil circulates through the engine and the lifters quit rattling.
Reconnect the wiring to the distributor and start the engine...the valve train should sound normal after a few second of the engine running'
Always check the oil pressure gauge during the above oil priming/cranking procedure...it should begin to show some psi.
Forum members fell free to correct anything that is out of order.
Always measure the depth of the oil pan to make sure the pickup tube is long enough to reach the bottom of the pan after inserting the upper end of the tube into the oil pump (just in case)...tubes that are too short can gradually come out of the pump while the engine is running
Always check the oil level on the dipstick before cranking the engine.
ALWAYS disconnect the wiring plug from the distributor so the engine will NOT start.
Always crank the engine over about 5 seconds at a time until oil circulates through the engine and the lifters quit rattling.
Reconnect the wiring to the distributor and start the engine...the valve train should sound normal after a few second of the engine running'
Always check the oil pressure gauge during the above oil priming/cranking procedure...it should begin to show some psi.
Forum members fell free to correct anything that is out of order.
Race Director
Joined: Nov 2006
Posts: 13,227
Likes: 7,824
From: Sunshine Coast, Queensland, Australia
2025 C3 of the Year Finalist - Modified
2024 C3 of the Year Finalist- Modified
2022 C3 of the Year Finalist - Modified
Cruise-In VIII Veteran
Absolutely, disconnect power wire from distributor, crank engine 15 seconds at a time, 30 - 45 second rest in between. Should see oil pressure on the guage by the third or forth crank. if new oil filter, may take a bit to fill the filter if you didn't pre-fill it. once you see pressure on the gauge. reconnect the power to the distributor and light it up. lifters should fill in seconds.
Race Director
Joined: Jul 2015
Posts: 13,082
Likes: 3,399
From: SW Florida.
a settled in motor will usually not knock from no oil pressure in a few seconds at idle. you may have the new pan hitting the crankshaft. that will bang so loud you will freak out. as 4-vettes said, crank the engine until you see oil pressure. then start it. same noise? get under it with your hand on the pan up front. have somebody start it. you will feel it.
Race Director
Joined: Nov 2006
Posts: 13,227
Likes: 7,824
From: Sunshine Coast, Queensland, Australia
2025 C3 of the Year Finalist - Modified
2024 C3 of the Year Finalist- Modified
2022 C3 of the Year Finalist - Modified
Cruise-In VIII Veteran
Well, perhaps they sent the wrong pan, perhaps you ordered the wrong pan. from whom did you order it? what did you order? perhaps it's something else entirely. first step. crank it till you see oil pressure, then start it. lets go from there.
Thread Starter
Intermediate
Joined: Apr 2019
Posts: 26
Likes: 6
From: Jacksonville
Thanks for the update.
sounds half way better. I killed the power to the distributor and cranked the car a few time. I saw the oil pressure increase. I also put my hand on the front end of the oil pan and I didn’t feel anything hit or tap it.
there is still a sound which is hard to explain. I recorded a small video so you can hear it.
sounds half way better. I killed the power to the distributor and cranked the car a few time. I saw the oil pressure increase. I also put my hand on the front end of the oil pan and I didn’t feel anything hit or tap it.
there is still a sound which is hard to explain. I recorded a small video so you can hear it.
Corvette Stories
The Best of Corvette for Corvette Enthusiasts
Top 10 Most Expensive Corvettes Ever Sold on Bring A Trailer
Brett Foote
10 Things Every Corvette Owner Needs (2026 Edition)
Michael S. Palmer
8 Most "Only Corvette Owners Understand" Quirks and Problems
Pouria Savadkouei
10 Reasons the C6 Z06 is Still A Performance Benchmark After 20 Years
Joe Kucinski
How Much Horsepower Every Corvette Engine "LOST" in 1972
Joe Kucinski
Top 10 DOs and DON'Ts for Protecting Your Convertible Top!
Michael S. Palmer
Top 10 Most Explosive Corvettes Ever Made: Power-to-Weight Ratio Ranked!
Joe Kucinski
150 hp to 1,250 hp: Every Corvette Generation Compared by the Specs That Matter
Joe Kucinski
8 Coolest Corvette Pace Cars (and Replicas) of All Time
Verdad Gallardo
Race Director
Joined: Nov 2006
Posts: 13,227
Likes: 7,824
From: Sunshine Coast, Queensland, Australia
2025 C3 of the Year Finalist - Modified
2024 C3 of the Year Finalist- Modified
2022 C3 of the Year Finalist - Modified
Cruise-In VIII Veteran
Sorry can't open file. however, it's always really hard to tell on a video. Just not like being there. have you tryed listening with a stethoscope or the old thumb on a screwdriver held to your ear trick?
Dr. Detroit
Joined: Mar 2012
Posts: 10,097
Likes: 4,027
From: New Braunfels Texas
What pan did you buy and what pickup did you use?
Corvettes have specific oil pans and oil pump pickups......you cannot mix and match these with over the counter 5qt passenger car pans......
Jebby
Corvettes have specific oil pans and oil pump pickups......you cannot mix and match these with over the counter 5qt passenger car pans......
Jebby
Thread Starter
Intermediate
Joined: Apr 2019
Posts: 26
Likes: 6
From: Jacksonville
I went to Auto zone and picked up a new soil pan and gasket. It went on perfect. I like this one better than the previous one.
in regards to the oil pump, I am not sure the model but it went on perfect. I reused the old pick up tube and made sure it was about 1/4” from the bottom of the pan.
the oil filter is full of oil and the dip stick registers full.
I killed the power to the distributor, and I turned it over a few times.
That noice continues. Should I continue to prime it. Could the oil pump be bad???
Any guidance is appreciated.
in regards to the oil pump, I am not sure the model but it went on perfect. I reused the old pick up tube and made sure it was about 1/4” from the bottom of the pan.
the oil filter is full of oil and the dip stick registers full.
I killed the power to the distributor, and I turned it over a few times.
That noice continues. Should I continue to prime it. Could the oil pump be bad???
Any guidance is appreciated.
Last edited by Edrush411; Apr 19, 2021 at 10:18 PM.
Race Director
Joined: Apr 2007
Posts: 11,152
Likes: 890
From: South Western Ontario
I don't know about the noise, but the pickup is not properly installed in the pump if you could move the pickup with a piece of wire after the pump and pan were installed. If it's loose like that then it will fall out of the pump.
Le Mans Master
Joined: Aug 2017
Posts: 8,336
Likes: 2,810
From: Cool Northern Michigan
I hate to be the one to tell but, the pan has to come back off.
You need to remove the pump and spin the pump shaft by hand. This will verify if the pump is defective. Which I doubt.
Was a collar installed on the pump shaft between the distributor & pump shaft? Was it plastic? Was it missing?
Quite common for those plastic collars to disintegrate. Then the shaft wobbles against the block.
That, could be the noise you are hearing.
And in rare occurrences, a too long of bolt is used to mount the oil pump. You can imagine the noise from the main bearing being forced against the crank journal.
You need to remove the pump and spin the pump shaft by hand. This will verify if the pump is defective. Which I doubt.
Was a collar installed on the pump shaft between the distributor & pump shaft? Was it plastic? Was it missing?
Quite common for those plastic collars to disintegrate. Then the shaft wobbles against the block.
That, could be the noise you are hearing.
And in rare occurrences, a too long of bolt is used to mount the oil pump. You can imagine the noise from the main bearing being forced against the crank journal.
Race Director
Joined: Jul 2018
Posts: 10,589
Likes: 8,410
From: San Antonio, TX/Mahopac, NY
2026 Restomod of the Year Winner
2024 Corvette of the Year Finalist - Modified
2024 Corvette of the Year Finalist - Unmodified
2023 C7 of the Year Winner - Modified
Oh boy. Drain the oil, pull the pan. Look inside the pan and you will see where the crank is hitting the pan, probably either up front or a baffle in the pan, that is exactly what that noise is that you are hearing. If that pick up is a press fit, it needs to be tack welded to the pump in the proper position. Otherwise, it will fall out and you won’t notice until your bearings are toast. Right now, your engine is fine, but you need to know what you are doing to keep it that way. Source the correct parts and install them correctly. Good luck!
Thread Starter
Intermediate
Joined: Apr 2019
Posts: 26
Likes: 6
From: Jacksonville
I am not familiar with “stroker “crank. This is a stock 350 engine in the car. Manual transmission. I’m not sure if this is important or not. I have everything taken apart and just gonna try a new oil pump. That would be the last thing I can think of. I’m not sure what else it could be.
I looked inside the new pan, and I do not see anything rubbing against the side or front, or rear of the pan. There’s no evidence of metal scraping it. I will try the new oil pump set everything correct. I’m referring to the pick line. I will give it one more go.
I looked inside the new pan, and I do not see anything rubbing against the side or front, or rear of the pan. There’s no evidence of metal scraping it. I will try the new oil pump set everything correct. I’m referring to the pick line. I will give it one more go.
Le Mans Master
Joined: Aug 2017
Posts: 8,336
Likes: 2,810
From: Cool Northern Michigan
People seem to be convinced the rod caps or crank is striking the oil pan. You state its not a stroker motor so there is no reason a stock crank would hit the block or pan.
Before you keep buying another oil pump, make sure the last ones are spinning by hand. I am 99% sure its NOT the pump itself . You have other issues.
Did you see a collar on end of the pump shaft? The fact that the noise is still there during cranking means there is something not right with the pump "install" or its shaft.
I think I would pull the rear main bearing and have a look-see if anything is amiss. Look up inside the pump shaft hole in the block at the distributor shaft end piece.
Before you keep buying another oil pump, make sure the last ones are spinning by hand. I am 99% sure its NOT the pump itself . You have other issues.
Did you see a collar on end of the pump shaft? The fact that the noise is still there during cranking means there is something not right with the pump "install" or its shaft.
I think I would pull the rear main bearing and have a look-see if anything is amiss. Look up inside the pump shaft hole in the block at the distributor shaft end piece.
Melting Slicks
Joined: Mar 2005
Posts: 2,094
Likes: 298
From: Midlothian VA
Thanks for the update.
sounds half way better. I killed the power to the distributor and cranked the car a few time. I saw the oil pressure increase. I also put my hand on the front end of the oil pan and I didn’t feel anything hit or tap it.
there is still a sound which is hard to explain. I recorded a small video so you can hear it.
sounds half way better. I killed the power to the distributor and cranked the car a few time. I saw the oil pressure increase. I also put my hand on the front end of the oil pan and I didn’t feel anything hit or tap it.
there is still a sound which is hard to explain. I recorded a small video so you can hear it.
Race Director
Joined: Jul 2015
Posts: 13,082
Likes: 3,399
From: SW Florida.
that did sound like big metal hitting sheet metal. post pics of the inside of the pan. reinstall the old pan and start it. it doesn't have to be the wrong pan, just dented in just the right spot. by pick line do you mean oil pump pick up tube? your old pan and oil pump worked. you needed to fix a leak. i would consider reinstalling the orig pump and pan with a new gasket and see what you see-hear.
Last edited by derekderek; Apr 20, 2021 at 05:41 PM.