1970, 442, W30 Sebring Yellow
FYI for anyone chasing a engine Noise.
I am posting something that I doubt many have heard about. If so please let me know. In early spring I started hearing a slight clicking engine noise that came and went. It sounded like a lifter or rocker arm issue. It got worse and didn't ever go away. I ended taking the pass side valve cover off to check the Valves/springs/push rods. I was able to trace the sound down to the oil pan, pass side near the front up high by the block. I was almost ready to have the engine lifted in order to get the oil pan off.
Luckly I know a retired oldsmobile mechanic with a lot of experience on 1970 w30 engines. All he did to stop the sound was use a lead mallet and tap lightly on the upper front corner of the pan. Over the years he has seen this happen on almost a dozen times, all on W30 engines. That is strange as I thought the w30 crank/block was no different than a regular 455 engine. If you get a loud clicking noise which sounds like a lifter and locate the sound to the front of the pan. Try lightly taping on the pan. We think the crank clearance is extremely tight there and hits the pan. Also, don't overtighten the pan bolts as its possible i might have done that, which moved the pan ever so slightly, even though the engine was rebuilt over 15 yrs ago and has not been apart.

Jim O
70, 442, automatic, sebring yellow, w30

 

Wow...that's interesting.

 

Everyone ive talked to (even avid Olds 455 people) are taken back. We can only surmize and think it might have something to do with the rubber gasket being able to shift or by tightning the pan bolts, it brought the pan close enough to the block that the crank hit started to hit either the windage tray or the pan itself. . Or another theory is the windage tray might have shifted somehow allowing the crank to hit it and it had nothing to do with the tightining of the pan bolts.
In any case, there must not be much clearance between things down there.

Jim O

 

Wow, That is cool- thanks for posting!

 

Whip your pan down start it put your hand on the pan if a rod bolt is hitting you will feel it then mark it with a marker. If you don't feel anything maybe look at the timing cover.
Debris off the road is always possible

 

I know a guy who years ago was in the used car business before salvage title law. He got a cadillac at auction for next to nothing that ran off the road and got a little banged up. Nobody wanted the car because it was rapping down below and everyone just assumed the motor spun a bearing. Turns out when it ran off the road, the oil pan was dented causing the crank to hit the pan and make noise. He took the dent out of the pan and sold the car for a hefty profit.