I searched for something about inaccurate dipstick readings and was surprised not to find anything, maybe you guys can give me a clue as to what is going on with mine, pictured below. When I push it into the tube there is some initial resistance which is probably from the black sleeve contacting the tube, I can push past that until the tube bottoms out in the metal cap.

Today I changed the oil, poured about a half quart into the oil filter and then the rest of that quart and three more into the filler hole. I then ran the engine for a few minutes, shut it off and let it sit for another few minutes. With the dipstick pushed all the way down (past the initial resistance and bottomed in the metal cap) it now reads full. Anyone know what is going on? It's supposed to take at least 5 quarts, right? I did put on an aftermarket oil pan a while back which looks exactly like the one that came off which looked original so I don't think that is the problem. I'm not sure if pushing the dipstick past where the sleeve contacts the tube has changed. If I were to stop at that initial resistance it would indicate another quart needed.

I am tempted to put in another quart, push the thing all the way down and call wherever that shows on the dipstick, FULL. But also keep an eye out for foaming.

 

5 qt's with a filter change should be spot on. Someone change the dip stick??
I'm thinking your right. put in 5 quarts all up. remark the dipstick.

 

If you are absolutely certain you have the original correct dipstick and tube I would stick with (pun intended) the mark on the stick. The goal is to fill the pan to a level just below the crankshaft regardless of how many quarts it takes. The best way to calibrate the dipstick is to drop the pan and mark the correct level on the stick.

 

You have so many bends and curves in that stick, it looks like a tranny dipstick.
But anyway, a little overfill never killed an engine.

 

They work as a pair. The wrong length on either part will throw you off. I measured a known good pair and got 19-5/8" from the bottom of the rubber to the "Full" mark along with a tube that is 9-1/4" from the top of the tube down to the rolled bead where it fits into the block. Measure yours and see what you get.

The dipstick is supposed to locate the top of the oil LEVEL, not the number of quarts needed to fill the pan. Larger pans can contain more oil with the same level in the engine. Your dipstick might be marked with "1 quart low" but that is just there to help you maintain the designed level in the crankcase.

Additionally you would want to verify the pickup to pan bottom dimension before installing any no-original replacement or aftermarket pan.

 

Thanks for those numbers, I'l check mine today, hopefully I can get to the "bottom" of this. Interesting comment about the ripples in my dipstick, I never gave that a second thought. Actually I really have no idea whether either the dipstick or tube are correct. I built the engine reusing those two existing parts, I do remember following a procedure that came with the Melling pumg for setting the pickup position, if I remember correcty there is a screen and it is down near the bottom of the pan.

 

Just made some measurements. I get the same 9 1/4" for the tube but for the dipstick I get 19 1/4" from the bottom of the black sleeve to the FULL mark. That means if I had the same 19 5/8" then it would read full at an even lower level. Does your dipstick stop when the top of the tube hits the black sleeve or does it go past that all the way up the metal cap? That is another 11/16" insertion.

Also, the dipstick is marked "Use SE engine oil" so at least it's not from a tranny.

 

It's actually 19.5" to the "FULL" mark on mine so your stick is either different than mine or you might double check the measurement. I get 20.25" to the "ADD 1 QUART" mark. I have stick "3862730".

 

No number on my dipstick.

The difference between yours and mine is only 1/4", that doesn't account for the discrepancy which is about 7/8", the distance between the FULL and ADD marks on my stick. At this point the only thing I know for sure is that with a new filter and 4 quarts of oil it reads full. My gut feeling is that for some reason my dipstick is going in too far, maybe the plastic sleeve has broken or worn (or wrong part!) and it is not acting as a stop, that would account for difference.

 

The stop is not supposed to move up the stick which means it is no longer accurate since you dont know its original location.
All stock pans take 5 quarts other than some HP pans that took 6.

 

Thanks MelWff, so that black thing actually is a stop? It would not surprise me that mine has deteriorated and failed, pretty much everything else did on my car when I bought it.

I found this thread in another forum, very interesting.
https://www.chevytalk.org/fusionbb/s...hp?tid/243408/
It's long and there is one very long post with a lot of missing photos but below that is maybe the money shot:

<<I just pulled a pan off of an engine and checked it. The full mark is 4" from the pan rail. This gives approx 1" below the lowest swing of the crank counterweights for clearance. Of course this would be engine off and all oil drained back full reading. Once engine starts pumping oil that would lower the level a little as it circulates.>>

But then the guy who wrote the very long post followed with this:

<<once the engine starts it lowers the oil level significantly more than you may realize, Id suggest re-marking the dip stick so full indicates an oil level at least up to the lowest swing of the crank counterweights, and adding a windage screen equipped type baffled oil pan, as its sure to increase the oil control>>