Need HELP - Engine Troubles after oil pan removal
Thread Starter
Heel & Toe
Joined: Jan 2013
Posts: 15
Likes: 0
From: Fort Worth Texas
Need HELP - Engine Troubles after oil pan removal
First, I am new to the board. Been reading a lot about my corvette and learning a ton. Over the last two weeks, I dove into my 1974 ( Stock 350 ) due to leaking oil around the pan. I decided to replace the rear main seal, the oil pan seal, and paint the pan. It was left on ramps for about two weeks, completely drained of oil. Tonight, filled back up with Amsoil 10w 40 and started. This is where it went bad.
Engine started knocking like crazy, I shut it down and figured I needed to prime the pump. I feel the oil pump is working because after about 20 seconds, I pulled the primer and it had a lot of oil on it. Restarted and same issue.
What next? I am thinking I need to get an oil pressure testing kit. What is the best place on the engine to screw in the fitting? Is there something else I am missing. I am afraid of trashing the engine...
Engine started knocking like crazy, I shut it down and figured I needed to prime the pump. I feel the oil pump is working because after about 20 seconds, I pulled the primer and it had a lot of oil on it. Restarted and same issue.
What next? I am thinking I need to get an oil pressure testing kit. What is the best place on the engine to screw in the fitting? Is there something else I am missing. I am afraid of trashing the engine...
Race Director
Joined: Jul 2004
Posts: 12,706
Likes: 329
From: Scottsdale Arizona
Could be any number of things but lets start with the simplest.
Did you seat the rod into the top of the oil pump when you put it back in? When you were running the oil pump by hand, did you notice an increased resistance?
Alternately, was there anything in the oil pan like a baffle or a wind age tray?
Did you seat the rod into the top of the oil pump when you put it back in? When you were running the oil pump by hand, did you notice an increased resistance?
Alternately, was there anything in the oil pan like a baffle or a wind age tray?
Thread Starter
Heel & Toe
Joined: Jan 2013
Posts: 15
Likes: 0
From: Fort Worth Texas
Thank you for replying. I left the rod attached to the oil pump when I removed it, I slid the pump back in place and torqued to specs.
I didnt feel resistance when priming, I was using a drill, ran for a bit and pulled it out noticing oil running down the tool. Assumed it was moving oil.
The pan has a tray, looks like its spot welded in place. I believe the pan is original to the engine.
I didnt feel resistance when priming, I was using a drill, ran for a bit and pulled it out noticing oil running down the tool. Assumed it was moving oil.
The pan has a tray, looks like its spot welded in place. I believe the pan is original to the engine.
Team Owner
Joined: Jan 2006
Posts: 37,637
Likes: 3,118
From: Crossville TN
I don't think you got the pump drive rod back in place correctly. Not sure what occurred, but it doesn't sound like any oil is being pumped. I would not try to start it again until you sort it out. At a minimum, remove the pan and pump to see what happened.
It's also possible that the suction tube was damaged, or the O-ring didn't get seated properly. Gotta be something down where you were working.
It's also possible that the suction tube was damaged, or the O-ring didn't get seated properly. Gotta be something down where you were working.
Safety Car
Joined: Jan 2009
Posts: 3,736
Likes: 56
From: anchorage ak
Does the electric gauge work. If so have some one watch the gauge while you prime it with a drill. If it doesn't work pull the valve covers an watch for oil to start to flow out the push rods. No pressure or no oil from the push rods pull the pan and pump. This is probably a dumb question but you changed the rear main seal, did the bearing get put back and did the main get torqued down? Stranger things have happened.
Thread Starter
Heel & Toe
Joined: Jan 2013
Posts: 15
Likes: 0
From: Fort Worth Texas
Again I want to thank everyone for replying. Its my first time posting and the responses have been awesome. To answer a few questions, I believe this has to be an oil pump issue. The only parts I touched were the rear main seal so the cap and the oil pump. Two thoughts last night, so the engine was pretty much drained of all oil. I put a brand new oil filter on it and didn't add any oil to the filter. Could that be a problem? And on the oil pump, I was amazed there was no seal where the pump attaches to the block, not the bolt but where the oil shoots up. Does that need a seal?
Last night was the first time I ever primed an engine. I had the primer on my drill and was running it clock wise. Is that correct? And about how long do you run it for? I keep going back to seeing oil on the primer when I pulled it up and inspected it. Is that a sign oil is being lifted or is that just oil sloshing around?
Overall I am worried I am going to open up the pan and see it exactly how I saw it the first time. Have no "Thats it!" moment, just me scratching my head...
Last night was the first time I ever primed an engine. I had the primer on my drill and was running it clock wise. Is that correct? And about how long do you run it for? I keep going back to seeing oil on the primer when I pulled it up and inspected it. Is that a sign oil is being lifted or is that just oil sloshing around?
Overall I am worried I am going to open up the pan and see it exactly how I saw it the first time. Have no "Thats it!" moment, just me scratching my head...
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Melting Slicks
Joined: Aug 2012
Posts: 3,487
Likes: 83
From: Titusville Florida
I do believe that you were going the right direction with the drill but there should have been a noticeable difference in the drill when it started pumping oil, it would have pulled the drill down (if that makes sense).
Melting Slicks
Joined: Aug 2012
Posts: 2,548
Likes: 379
From: Woodinville WA
If the motor started knocking immediately - I'd be looking at interference with the rotating assembly and the pan. Don't stop look just at the pan.
Did you remove the dust cover from the transmission? If an automatic, putting the dust cover on is a task fraught with ways of messing up and getting a knock... and please, don't ask how I know this (sigh)
Did you remove the dust cover from the transmission? If an automatic, putting the dust cover on is a task fraught with ways of messing up and getting a knock... and please, don't ask how I know this (sigh)
Thread Starter
Heel & Toe
Joined: Jan 2013
Posts: 15
Likes: 0
From: Fort Worth Texas
I am really starting to think I was on the right track but didn't finish the job. I was running the drill for maybe 30 second bursts. From looking online, I am seeing people running it for up to 20 minutes. That seems long but maybe I need to take off the valve cover, prime it until I see oil coming out the rocker, and if I dont after 5 - 10 minutes, go after the oil pump. Does that seem logical?
Thread Starter
Heel & Toe
Joined: Jan 2013
Posts: 15
Likes: 0
From: Fort Worth Texas
Honestly the sound does sound like someone is kicking the oil pan. It starts instantly. I removed the splash shield between the oil pan and the transmission. It had two tabs that would block the pan from coming down so I unbolted it enough to swing it down, out of the way. Its the same cover the starter slides back into.
Le Mans Master
Joined: Nov 2006
Posts: 5,262
Likes: 283
From: I'd like to propose a toast... to internal combustion and wind in the face.
Last night was the first time I ever primed an engine. I had the primer on my drill and was running it clock wise. Is that correct? And about how long do you run it for? I keep going back to seeing oil on the primer when I pulled it up and inspected it. Is that a sign oil is being lifted or is that just oil sloshing around?
Clockwise is the correct direction. What size was your drill? 3/8" or 1/2"? Typically, when the oil pressure comes up the resistance will be enough to really bog a 3/8" drill down and can burn one up in short order. I always use a 1/2" drill and again, I don't stop until I see oil from the push rods. If it were me I'd try to re-prime the engine and if I didn't feel some fairly serious resistance from increasing oil pressure I'd feel like I was on to what ever the issue is.
Melting Slicks
Joined: Aug 2012
Posts: 3,487
Likes: 83
From: Titusville Florida
When I prime an engine I'm not satisfied until I see oil coming from the tops of the push rods. So, to answer your question about how "long" should you prime your engine, long enough to see oil coming from the push rods would be my personal answer.
Clockwise is the correct direction. What size was your drill? 3/8" or 1/2"? Typically, when the oil pressure comes up the resistance will be enough to really bog a 3/8" drill down and can burn one up in short order. I always use a 1/2" drill and again, I don't stop until I see oil from the push rods. If it were me I'd try to re-prime the engine and if I didn't feel some fairly serious resistance from increasing oil pressure I'd feel like I was on to what ever the issue is.
Clockwise is the correct direction. What size was your drill? 3/8" or 1/2"? Typically, when the oil pressure comes up the resistance will be enough to really bog a 3/8" drill down and can burn one up in short order. I always use a 1/2" drill and again, I don't stop until I see oil from the push rods. If it were me I'd try to re-prime the engine and if I didn't feel some fairly serious resistance from increasing oil pressure I'd feel like I was on to what ever the issue is.
Once mine caught prime I didn't stop until I saw oil coming out of the push rods 
Thread Starter
Heel & Toe
Joined: Jan 2013
Posts: 15
Likes: 0
From: Fort Worth Texas
Thank you. I have a 1/2 inch concrete drill so I should have enough power to do it. I will remove one of the valve covers and run it until I see oil. Sounds like if I don't after around 5 minutes of solid drilling, I probably have a oil pump issue. I will let you know how it turns out, should get to it by tonight or tomorrow.
Race Director
Joined: Jul 2001
Posts: 15,892
Likes: 42
Thank you. I have a 1/2 inch concrete drill so I should have enough power to do it. I will remove one of the valve covers and run it until I see oil. Sounds like if I don't after around 5 minutes of solid drilling, I probably have a oil pump issue. I will let you know how it turns out, should get to it by tonight or tomorrow.
Team Owner
Joined: Jan 2006
Posts: 37,637
Likes: 3,118
From: Crossville TN
The dimensional relationship between the oil pan/tray and the suction screen is important. If there is not enough of a gap between the suction screen and the tray/oil pan, little [or no] oil can get sucked up into it. Or, if the suction screen is down too far, the pickup tube can lose its seal with the oil pump input: result is NO oil.
In the original build, there is a plastic/phenolic transfer tube which passes the oil from the pump; if that is broken/cracked/missing, no oil will flow.
There are a lot of possible faults in the area of the pump which can cause your symptoms. You MUST drop the pan again to check all this 'stuff' out; otherwise you risk a major engine failure.
In the original build, there is a plastic/phenolic transfer tube which passes the oil from the pump; if that is broken/cracked/missing, no oil will flow.
There are a lot of possible faults in the area of the pump which can cause your symptoms. You MUST drop the pan again to check all this 'stuff' out; otherwise you risk a major engine failure.
Le Mans Master
Joined: Jul 2006
Posts: 8,117
Likes: 104
From: charlotte north carolina
as superbuick posted, it could be interference with the dust cover. i didn't get the tabs on the cover hooked onto the pan once and the noise scared the (insert word here) out of me!
Bud2
Joined: Jul 2005
Posts: 1,237
Likes: 4
From: Warrnambool Victoria
The priming is just insurance that everything is in order. You said there wasn't any resistance. There should be a noticable resistance and you should prime until you see the oil from the rockers. I'd prime again and do it correctly. If it still knocks on start up stop and drop the pan. You gotta see what's going on in there.
Bud.
Bud.