I was checking under the car for a tranny leak and heard a scraping noise coming from the oil pan. When I touched the sump part of the pan it felt like something was hitting it on the inside. Oil pressure was good (50psi)but engine was cold. I cannot hear the noise from up top or standing next to the car even if I rev the engine.. Anybody have an idea what is causing this noise?

 

That sounds like it could be a problem. An audio posting would be helpful. I'm almost close enough to listen in person. My first thought is something connected with the oil pump pickup. Has anything been changed associated with the pan or the oil pick up? Has anything been dropped in that could have lodged between the pick up and the pan? Some pans have spot welded baffles in them. Perhaps one is loose. Continue monitoring the oil pressure until the problem is resolved.

 

I changed the oil pan a year ago and took it to Cruisin the coast never heard any noise. Only used it about six time since then goin to local car shows. Noticed a trans drip and decided to check it out. Remove trans torq convert cover, front seal not leaking put cover back on and started engine. Crawled under and heard noise. Thought cover was rubbing took it back off started engine still had noise.

 

Jack the car up high as you can and place the jack stands under the frame. Start the car up and put a screwdriver handle by your ear and the other end to the oil pan. This acts like a stethoscope. Listen to hear any scrapping noise around the oil pan. If you can hear it, looks like you're going to take the oil pan down.

 

thanks ELY442 but that is how I heard the noise. I was wondering if anyone else had this happen and what was causing it before I took it down. As far as I know nothing should be hitting from inside the oil pan.

 

Assuming nothing catastrophic has occurred. Wondering if the dipstick might be hitting the crank/rod.

 

Pull the dipstick out to see if the noise stops. If not, that's not it. Dropping the pan may be in your future.

 

"When I touched the sump part of the pan it felt like something was hitting it on the inside."

Crank counterweight?

Is your engine a big block with a smallblock oil pan?

- Eric

 

If something is hitting it may be wearing off metal. Cut open the oil filter and I don't think I would run it until I knew what's going on. Nothing should be hitting the oil pan, period. Time to get out the🔧

 

Cant seem to get the audio of the noise to upload but I put my stethoscope on it and it is loudest in the center of the oil sump and as I listen up the sides of the pan it goes away. Kind of sounds like an AC compressor. I think it is the oil pump making noise or the pick up tube hitting but I don't know why the tube would start rubbing now. I'm gonna change the oil and check filter.

 

When you changed your oil pan, did you remember if the pick up tube was "pressed on" or "bolted on"? I heard stories about the "pressed on" tends to loosen up and fall off and can caused damage to your motor while you're driving.

 

The tube is definitely the press in kind and as far as I can tell when I had the pan down all parts are factory install. I figured from past experience with Oldsmobiles that the timing set needed to be changed but when I got there it was already done. Had the new set so I changed them anyway but everything else appeared to be factory parts . I changed the oil and filter. Cut filter open and checked for metal didn't find anything. also checked drain pan for sparkles and found none. Started with new oil and filter noise is still there. The sound is like gears meshing together or a noisy AC compressor. Listen with stethoscope all around and the further you get from the center of the oil sump the less you hear the sound. put the scope on the dipstick tube and no noise in fact I put it all around the pan where it meets the block and barely hear any noise.

 

I would expect the oil pump, like any pump, to send pressure waves (albeit very mild) through the oil. When these hit the thin metal of the pan, they might be amplified. Maybe you're making too big a deal out of this? I think the only way you'll know for sure is to drop the pan.

 

Years ago I had this same problem with my 67 442. It turned out to be the crankshaft hitting the oil pan ever so slightly because I dented the pan slightly in the forward section when removing the engine and setting it on the floor. Let me tell you, there is not much clearance in that area of the pan!

 

If the oil pressure is good, you have a very small problem. I would drop the pan and have a look see just to make sure you don't have a bigger problem going on. My 2 cents.