Oil Levels.

Guy Paris · #1 09-07-02, 09:31 AM

Not trying to beat a dead horse to death, however: I was looking at TCM's "Pilot's Handbook on Engine Operation, Checking oil level. It states:

Oil level should be checked before each flight. With tricycle gear aircraft, the position of the nose wheel strut can determine the oil level reading. Unless the engine is level, the reading on the oil dipstick can be misleading and, in many cases has led to overfilling. Overfilling can result in excess oil being thrown into the cylinder walls and burned. the result is a high rate of carbon and residue build up plus useless oil consumption.

hmmmm. strange oil consumption, oil on belly, stickey turbos! ( I don't have any turbos) I have had the others.

Over the years I have noticed the different aircraft attitudes Re: nose wheel strut positions on different aircraft. It sure makes a difference on my readings. Think of tipping a glass with a straw in it! Guy, old72driver....

GMAs · #2 09-07-02, 02:27 PM

All good pilots... like Skymaster owners... know where the dip stick goes into the pan on the engine... and levels accordingly...

But,.....

Just in case some are missing the levels... if the fwd engine reads low and the rear reads high... and the front engine has a crutch under the spinner to hold it up...and the wheel rim has a flat spot on the bottom... it might be in a nose down position...

However,....

If the front engine reads high and is hard to get at... and the rear engine reads low... and the prop has bent tips... and the booms have a new bend in them at less than 45 degrees up... and the rudder strikes are ground off... then you know the plane is in the nose high attitude...

How much difference in the oil level will depend on what weight the oil is... and if it has been aireated from flying inverted...

all these factors need to be considered before you can determine if its a quart low or not.. before you decide if you want to go fly it.... smile GMAs

WebMaster · #3 09-07-02, 05:31 PM

That's why my oil is funny some times, that upside down stuff. I'm working hard on the barrel rolls, to make the smooth transition to right side up, but keep getting stuck in the upside down part.

Bob Cook · #4 09-08-02, 10:33 AM

Guys

There is a much easier method to determine oil level.

When you wipe down the aircraft figure out how much came off on the rags. If is close to 1/2 qt then add a full qt to be on the safe side.

Little harder on the rear engine. You put a bucket under the drain and when you come to fly it next time multiply the amount collected by 4 and add that amount to the engine.

must be more accurate and scientific.

bob

Don Hickman · #5 09-08-02, 10:17 PM

You guys aren't being exactly helpful. Well, except for Larry.

After my latest oil change and adding Bob's recommended AVblend, I'm now showing 6 qts on the stick, even though I know we put in 8. So I flew to Atlanta and back. Now showing 5 1/2 qts. But I know darn good and well that there's 8 in there minus the half it took to get to Atlanta and back. What gives? Crazy oil dipstick!

Maybe Larry has been sneaking down here to Indiana and flying my plane in order to practice those barrel rolls.

And the plane is level when I check it.

Bob Cook · #6 09-09-02, 12:02 AM

Don

Seriously (for a change) The oil levels will vary. Sometimes the oil gets stuck up in the upper galleries or something but many times it reads low and the next time I check it ........hmmm reading high.

I finally gave up and since I know that I do not burn very much I will leave the low reading and wait for the next trip or at least the oil to settle overnight. Voila........... back to normal.

I tend to keep it somewhere around 6 and add 1/2 qt at a time rather than dump a whole qt in at once.

this works for me.. I run w100 in summer and multi viscosity in the 4 cold months.

bob

GMAs · #7 09-09-02, 11:45 AM

Ahhhh what we covered before was that cont engine sent out a SB that covered the oil level problems in the engines...and that you need to go to their site and get a copy of it...

Seems that they can vary the lenght of the tube... tube... going into the engine... which can change the reading of the fixed length tape that you read the oil level on... naturly if the tube is long then you are going to read lower than what is actually their... if it is short then you are going to read higher levels than what is their.. kinda thing...

Now... don't over fill the engine... EVER... EVER... if you do and I find out... your life will never be the same again... smile...

Here is what we tell 'em to be safe... when you change oil.. and/or filter... put only 8 quarts back in... DO NOT GO BY THE DIP STICK LEVEL UNLESS YOU HAVE CALIBRATED IT... We had one person put 12 quarts in... and then TRY and go fly... Well... lets say they don't have to oil the runway anytime soon... not to mention that he had to get a new engine... kinda thing...

NO MORE THAN 8 IN THE ENGINE... yep count the quarts that you are putting in.. if they are not reading right then you need to calibrate your dip stick... and that is done by changing the Tube lenght... Cont engine has done some fancy low tech things.. and this one seems to work... they cut the dip stick tube and put a rubber hose in line... by changeing the lenght of the rubber line.. you can change the reading of the dip stick ... they also asked that you check for the correct dipstick before you start playing with hose lengths..kinda thing...

So go to their web site and check it out first and make sure you have the correct one.. ya they do get mixed up somehow... and you might not have the right one... they used to give them away but, now they are charging for the dipstick tapes... your mechanic will cut it to lenght.. and re-rivit it back on to the handle..

but,... it sounds like yours is not for your engine if its reading low when you put your oil in...

HOW TO CALIBRATE IT... is easy... start with 4 quarts... after changing oil.. and not starting the engine... then go to 6 and finally to 8.. checking the level against the markings on the stick... don't worry about the engine oil up in it... it is taken into account..and while could make up a quart difference... the filter and engine will absorb 1 quart... it is not considered in the level of things... and as bob says.. after runing is not the time you want to top it off... 8 quarts is the maximum that should be in the pan... and what it reads when runing is not the same... it will be around 7 or 6-1/2 or so... but, shouldn't go below 6. let it stand over night and it will come back to where it is when you put the oil in...

So now what if its reading high... you shorten the hose between engine and dipstick tube... by pulling it out further... or else changing the tape... same if its not reading enough... you push the tube in.. or get a longer tape... but, under no conditions should you try and go more than 1 quart difference.. if it is over that range.. new tape... is required.. like in your case ...

Start with changing the oil and checking the stick.. take notes and write it down ... you put in 4 and it reads ??? you put in 6 and it reads ??? you put in 8 and it reads ??? kinda thing... from that you can measure the length of markers... and know then what length you need to read right...

Hope this helps GMAs..

Don Hickman · #8 09-09-02, 11:36 PM

Thanks, GMAS. As soon as I get back from Mexico I will get with my mechanic and we'll work on calibrating the dipstick. That's got to be the problem since it always shows 6 right after an oil change (and filter) and I know we put 8 in it.

So that means that I've been putting too much oil in when I've run it up to 7 and that explains all the oil on the belly, etc. that Dave keeps complaining about! I keep telling him that his 10% of the plane is the only part that gets dirty and needs cleaning!!

Guy Paris · #9 09-10-02, 10:37 PM

Hey Guys,
`I am looking at my Cessna Service Manual 1974 thru 1980 (for) Model 337 & Turbo Series. Paid 100 bucks for it in 1992, time has really flown! I am in the servicing sheet (sheet 2 of 4) change 7. (page) 2-15....

NOTE

Oil capacities for the aircraft are given in the following chart. to minimize loss of oil thru the breather, fill to specificied oil level on dipstick for normal operation (flight of less than three hours duration). For extended flight, fill to FULL mark on dipstick. Do not operate with less than MINIMUM-FOR-FLIGHT quanities listed. If an external oil filter is installed, one additional quart of oil is required when filter element is changed.

CAPACITY (TOTAL) 8, CAPACITY (TOTAL WITH FILTER) 9,

NORMAL OPERATIONS 7, MINIMUM FOR FLIGHT 6....

I copied this out of the book as close as posibile, remember the yrs, and models. The book also says the leveling marks are two screws on the pilots side below the side window. One could place a level across them to see if what you think is level is indeed level... How about when one next changes the oil and adds the required amount, (9), (8), or (7) one marks the that spot on the dip stick? The next time I change the oil and filter I am going to put in (8) quarts, run it wait 30 minuts, the book says (5) or (10) minuts and see what the stick reads, then I will mark that spot as (7), then I will eye ball it for the quart above for extended flight and a quart below for minimum.... Hey GMAs, would you know if this page has been superceded? Guy ....old72driver....

kevin · #10 09-11-02, 12:14 AM

Guy,

Everybody decides to do what they think is best.

For me, after 6+ years of Skymaster ownership, it is clear that if I maintain an oil level of more than six quarts on the dipstick (which would be seven quarts, including the quart in the filter), the excess blows out on the belly at a great rate. The belly requires very little lubrication in normal operation...

Sometimes the manual is wrong. As an engineer on other products (including aerospace products), I know that to be true from personal experience.

Blue skies,

Kevin

Guy Paris · #11 09-11-02, 08:53 AM

Kevin,

True, everyone has to decide for them self, However given all the discussions Re: oil on belly, turbo troubles, crazy stick readings,etc. etc. I feel its never to late to listen and learn from others. I my self with 11years of Skymaster ownership, 50 years of flying and being the end user, still listen and learn. I marked the stick several years ago. Guy.... old72driver....

GMAs · #12 09-11-02, 11:47 AM

The stick tape has marks on it... Ya I have seen some people take a small grinder and put cuts in the tape along the way... also seen them score the tape where the levels are supposed to be... but, then again..... I have seen tapes break off too at these points...

The original and replacement tapes are marked by using etching methodes... like how they mark the hose tags... its kinda a electrochemical burn kinda thing...

So if you have scored it .. ground it... or othewise fractured the SS tape... well... smile..

Ok someone in the back of the room says.... what should we do... Hmmmmm..

Well the best way is to take a small prick center punch and right in the middle of the width of the tape... put a punch mark... some take and drill... or should I say burn... their way thru the center of the width of the tape.. its not a big hole mind you.. it is no more than a 1/32 to a 1/16 inch kinda thing.. so you don't weaken it too much... but, drilling the tape is kinda tough as it is SS for most...

replacements are not expensive... we have gotten a few under the .. well its the wrong one... kinda thing and cont engine has come thru with a lower price... to change it you remove the two rivets up under the handle and replace... here we recomend that you use a hand punch to make the new holes after marking it for the right location by using the holes in the handle... then a simple matter of re-riviting it back in place and fileing it round again...

Oh and runing the engine... and then measuring the oil... well... if you change the filter... you are going to take it down a little... but, if you will check it at oil change... don't worry about what is in the engine... its not going to be that much if it has been run in the last few days... but, as bob says... close enough after you run it... check it... but, I would not add any... as it has its 8 quarts... and one for the filter... kinda thing... also.. if you changed the oil filter... wait to add that last quart... is what some do... I think its not really required.. but, if you have the time... It is not a bad idea to add it after the pump has filled the oil filter... back up...

Keeping track of how much oil is used in filght is a art.. but, simple.. always check it the same... no you don't have to have a builders level on the screws... its not that critical.... just check it ...Oh say each time after the engine has been shut down for a hour... or before each flight of the day kinda thing... if traveling... after fueling... but, that is where the dip stick tape should have been already calibrated... pays off...

Fly safe... don't overfill.. don't run without... as each will cost big bucks... GMAs

kevin · #13 09-11-02, 06:22 PM

Guy,

I certainly agree with your comments about listening and learning, that's why I enjoy maintaining this web site, for example.

All I was responding to was the portion of the message that says "Cessna says to put eight quarts in for long flights", which I think does nothing but lube the belly.

Thanks for your contributions to the site, if I wrote anything that offended you, that was not my intention and I apologise.

Kevin

GMAs · #14 09-11-02, 10:45 PM

Nope you didn't offend me... but, watch your step next time their bud... we won't take much more of that... smile.. GMAs

Dale Campbell · #15 09-12-02, 10:15 AM

Hi Guys,
I have the H model & have the same problem with oil level. When I first got my ship 2 years ago, the mechanic changed the oil & filter. When I picked up my ship the next day, I checked oil & it read 7 quarts. I also found rags laying on top of the oil cooler. I proceed to chew his ass out for not filling both engines & leaving the rags on cooler. He said he did put in 8 quarts plus one for filter. I made him put in one more quart each. 25 hours later I changed the oil myself & found out when you put in 8 quarts it only read 7 quarts. So now I know it always reads a quart lower than what you have. The extra quart did not blow out because I had put on the M-20 air/oil Separators from the beginning of ownership. By the way they work great. I get very little oil on belly & tail feathers.