The Stovebolt Site Forums The Shop Area Engine Shop oil level

my 41 248 takes 8 qt to fill,,, now that right to the top line on the stick... it has a filter that might hold a qt.. now ! do I have to add an extra qt because once its running that filter will be full and the oil pan level will be a qt low ? or was there a new dip stick that came with the filter kit,, to count for the extra oil needed, thanks guys for any help

If you have a bypass filter most of the oil will run back into the pan when you shut it off, that is assuming it's plumbed correctly. I'd put the equivalent of the filter in oil in to make sure it doesn't fall below the pick up.

When the oil is at the line, you are good to go. Fill it to the line, run it 'till she's hot, shut 'er down and check again. Top up to the line again. This will take care of the oil that is now in the filter. Most of the oil stays IN the filter body when the engine is off. At least it does on mine. You can tell if you pull the top off. Note the oil level with the filter in place.

Kurt

Kurt is correct, the oil should stay in the filter. The metering hole that allows for the oil to return is almost at the top of the filter housing, not at the bottom.

thanks guys.

Gotta disagree with the plumbing. The return hole is at the bottom of the canister according to the Fram instructions I have. If it's plumbed correctly much of the oil will return to the pan. Mounting instructions.

It really doesn't make any sense for the filter body to drain when the engine is shut off because:

A. It has to fill up again when you start the engine which will give you low oil pressure just when you really need good oil pressure.

B. You will have a dipstik oil level problem where the stick will read a quart high.

This doesn't mean you aren't correct about your instructions for the filter you reference, but I bet the the oil won't drain back into the engine either when it's shut off.

Seems like the oil actually comes up the center tube, so the level won't drop below the top of the tube or the side outlet.

It's been way too long since I got into this, but I seem to remember changing the oil for the first time on my '53 chevy, and trying to drain the oil out the bottom, which didn't work, and finally unbolting the filter and dumping it out.

This was when I was a dumb and stupid 16 year old, and before I learned about the joys of a turkey baster.

Kurt

I would always assume that the oil level when the engine is running (and level) is correct. I run the engine, shut it off, and check the oil level right away.

Actually, the return line orfice is halfway up the center tube, so the housing will only drain partway, and it takes a couple of hours for the level in the filter to stabilize after shutdown. The difference on the dipstick will be about 1/2 quart. The orfice is usually about 1/16" in diameter.
Jerry

Hah! I agree with all of you!

I had an original GM canister on my Chev, stayed full.

Currently, I have a kranilator on my GMC, and the dang thing empties into the pan, just as Tiny describes. I can't check my oil, unless the truck has been running within a few minutes.

I'm going to replace the kranilator, with a NOS Frantz filter I have. Then, no more drain out.

You're correct on the plumbing, but the outlet line is connected to the tube inside the housing, which has a metering hole much further up. It does not drain at the bottom of the housing internally.
Jerry, I was just looking at the Fram housing that came with mine, the metring hole is about 1" from the top of the housing. I suppose that there can be variations between brands and years of manufacture as to where that hole is located.

I'm going to have to check the next time I change the filter. If I remember right it's fairly close to the bottom of my Fram canister. At any rate "much of the oil" (not ALL of the oil) will return to the pan. Remember the complete canister will be full of oil when the engine is operating. Also, if one is using modern multi-viscosity 10-30 or 10-40 oil it gets really thin when hot so it won't take THAT long to drain back, even through a fairly small hole.

Why would a 10w-30 or a 10w-40 oil get really thin when hot???? I thought the object of the
muliti-viscosity oils was to flo thin when cold and give the protecton of a 30 or 40 weight oil when hot.

Denny G

Yes, some by-pass filter canisters drained almost to the bottom and some did not. Fram made a "Sludge Siphon" to remove the oil and gunk that did not drain from the bottom of some of its canister filters.

Yes 10W-30 means equivalent to 10 weight oil when cold and equivalent to 30 weight oil when warm. Therefore straight 30 weight oil and 10W-30 weight oil would have about the same viscosity when warm.

I don't profess to be expert on the subject of multi-viscosity oils but I can tell you that the 10-30 I drain hot is a LOT thinner than the 10-30 I pour in cold. My understanding of m-v oils is that the higher number means they provide the "protection" of the higher number straight weight oil not that they obtain the thicker viscosity. Do I understand wrong? After decades of changing oil and watching what I put in and drain out I doubt it.

The W refers to a grade at a "cold" or W Winter temperature. No "W" means a "hot" viscosity grade.

I do not know if I have ever seen a 10-30; but, I suppose that is possible. I have seen 10W-30 (as described above).

I'm with Tiny, any oil gets thinner with temp, as stated in the wiki article: "The viscosity of a multi-grade oil still varies logarithmically with temperature"

Bill

Yes, that is correct.

A 10W-30 oil gets thinner when warm.

"The viscosity of a multi-grade oil still varies logarithmically with temperature, but the slope representing the change is lessened."

I'd have to see a viscosity table to see if a 20W-20 oil (if there is such a thing) gets thinner when warm.

Tiny referred to a 10-30 oil but I took him to mean 10W-30.

Shell-Rotella and Castrol are working on (selling?) a 0W-30 oil for fuel economy, but very tight bearing clearances are needed to maintain oil pressure.

My filter behaves exactly as Jerry described and the very small hole is about half way up the pipe.

AC or Fram?

Ahem. I stand corrected. I just took the kranilator off my truck, it drains to about half. Turns out I have the wrong dipstick. I guess that makes me a dipstick!

Here is the Fram sludge siphon.

I'm glad Fram labelled that, so you don't get it confused with the other sludge syphons!

What a cool thing to have in the garage.

you guys have me lost a bit.. might be a blonde thing,,, but when I change the oil... I pure like two qts in the top of the filter and it seems to have no bottom,,, but I does stop taking oil... but when I remove it for a oil change its almost empty. all this full not full I didnt want to open a can of worms... but if these after market add ons.. then oil level issue must come up.. some of these cans I seen must take two qts or more,,, and running a motor over filled is almost worse than low... I seem to have great oil pressure with 8 qt. and its right on full line... is there a way to tell this came with the truck so the dipstick level would of been taken into consideration... any of you guys have a instruction book on these puppies...

katrina,

What year/brand truck do you have? I found one of your posts where you mention 1940. The 1940 Chevrolet Truck Owner's Manual shows 5 qts for regular oil change. Added to this would be the amount needed for the filter that is being used.

Most of the AC accessory oil filters were 1-qt, but a 2-qt AC filter was usually also available.

The oil-filter instruction sheets (and Owner's/Operator's Manuals) usually state to run the engine, then stop the engine, let the oil settle, and then fill to the line on the dip-stick (I assume this is for filters that do not drain to the bottom). Some instruction sheets state to add one or two quarts (depending on the filter) to the normal addition/amount of oil at an oil change.

http://www.stovebolt.com/techtips/engines/oil%20filters/index.html#is

Some people who have filters that do not drain to the bottom (all of mine are like this), empty the oil pan and empty the canister. Then we add the normal amount of oil to the oil pan and one or two quarts to the oil canister (with new filter cartridge in place) before we seal the canister. This might get oil circulating through the engine more quickly.

Tim, I left the "W" off because I was too lazy to type it. I had no intention of confusing the discussion. The whole intent of my initial post was to make sure the original poster understood that all of the oil does not stay in the filter because there were no anti drain back provisions then. I certainly had no intention of starting a debate on who knows most about the viscosity of oil and the construction of bypass oil filters. This has gotten way past where I tried to contribute, to the point of picking nits, so I'm done.

well that takes the fun out of it... It does give me an ideal of using adapters and reducing the hose to the shop vac... woo hoo .. it does say wet or dri,,, I never tried motor oil,, but that little sucker rocks...

Katrina,

I have found the easiest way to empty out the filter body is to use a turkey baster. Takes 4 or 5 min. Then wipe it out with a couple of shop towels. 'Course the turkey baster never returns to the kitchen after such abuse.

Kurt

Kurt,

I also used a baster until I found that Sludge Siphon on eBay for little more than the cost of shipping.

I'd like a sludge Siphon for the name alone!

Kurt

I run olive oil in my truck,, so I guess the baster still good for the bird.. going green. it does smell like fries when I check the oil.. lmao

The multi-viscosity petrol sludge remover, and turkey baster. Gotta get one of them.

dumb blonde girls been using a 20 ft clear plastic gas line 3/8" and a small 110v vac pump to clean out radiators res. brakes, power steering, rear ends and if the line is full before I empty what I was working on. I just blow it out and redo. on the filter can its less than a 1/4 cup so I been just using the blue shop towels... I need to get a baster. thats poor man smarts there.....

Returning to the original discussion and to confuse matters even more, GMC had differing oil pans. I remember seeing one for a 302 that took an extra few quarts of oil. If my memory serves me there is a combination that takes upwards of around 10+ quarts.

My 248 in my GMC COE also takes 8 quarts, maybe 9, I can't remember, because it has the very large bypass filter which acounts for the 2 extra quarts as Tim mentions above.

I find that a small drill pump syphons out the oil filter cannister in about 5 seconds. I prefer that method over the turkey baster any day.

When you change your oil, install a new filter and if you have the big filter, roughly about 9" tall, pour in 2 quarts into the housing. If you have the small filter, add 1 into the housing and dump the 6 quarts into the engines.

Being that it is a GMC engine, it will take at least an extra quart compared to the Chevrolet engines due to the larger oil pan/engine.

Phew! I think I said all that I wanted...

Jeff

I start with filling the filter. and pour the rest in the motor takes 8 qts thats alot for a 6 cyl because engine oils main job was heat removel