Jump to content

Can I siphon oil out of my tank instead of draining?


Roger Lee
 Share

Recommended Posts

This question was taken from another forum and is good to review.

 

Quote:

"Would it be permissible to change the oil (less filter) by pumping out the oil tank with big syringe, pump, siphon, ... This would not require removing any fitting.

 

Paul"

 

The short answer is, Not a good idea.

 

You should not siphon out the oil. For one thing there is a plate half way down in the tank to help prevent sloshing and foaming. You won't be able to get past this very easily if at all. You will not be able to remove any debris at the bottom of the tank, although you really shouldn't have any. You will allow any lead to build up that won't be drained. The engine should be warm and the oil plug pulled and the out to drain. At about the half way part an oil sample should be caught for analysis. The filter should always be changed with the oil. The best way to check a filter is after it is cut and the element taken off the metal center is to take a jar with an inch of fuel in it. Drop the element in it and shake it around really good. Then pour out the fuel over a white paper towel which will catch and make very visible any particles of any kind. You will be able to see carbon, metal or what ever may be there. You can even run a magnet over the debris. The filter element will be clean and you will see things you couldn't see trapped in the filter with this method. If you use a steady diet of 100LL then you may once in a while want to pull the tank and clean the gray paste lead out of the bottom.

 

p.s.

Some have installed the quick drain on the bottom of the oil tank. Technically this isn't approved for the CT. On experimental's it isn't any issue. I personally don't care for them because it takes for ever to drain the oil and it drains so slow I always figured a faster flow would do a better job of taking any debris out with it. Just my own thought.

Link to comment
Share on other sites

Works for me if you guys would like to do it. We would just need a time and date.Any of you can post a date on the calendar for a group chat and talk it up. That's what this chatroom is all about. It's ours, no one person can say "They own the ink". Democratic not autocratic.

Link to comment
Share on other sites

  • 1 month later...

Anyone have a recommended way to install the oil filter? I have seen where this has been filled with oil and then quickly put on the engine while catching the oil running from it with a small drip pan. I've also seen where the filter has been filled, then tipped to drain out some of the oil to make things less messy. The question is, what is the best way to bring oil thru the new, partially filled filter and into the engine without introducing air into the oil system? Should the top plugs be pulled and the engine be propped 20 or 30 revolutions until oil is pumped back into the engine? What is the "normal" amount of oil that needs to be added to refill the 912 to proper level?

Link to comment
Share on other sites

I can tell you the right way.

 

Someone ask about siphoning oil out of the tank instead of draining. DON"T. If you remove your tank and look inside you will see a baffel about half way down and the surrounding screen and the plate on the bottom. All this prevents the contaminants (i.e. lead and carbon and debris) from being taken out of the tank if you try and siphon verses draining. Always drain the tank. I don't even like the quick drains that screw onto the bottom of the tank. (p.s. they aren't technically approved anyway) I think they drain too slow to help remove all the contaminants. The prop should always be turned to hear the gurrgle prior to opening the oil system and then never turned again until the system has oil in the tank and the filter is in place. The oil should be warm when draining and if you catch a sample for an oil analysis then it should be caught about half way through the draining.

The oil filter should be pre-filled with oil. That is the preferred method. I use a little oil from one of the three quarts to fill the filter, then the level settles back down to the bottom and I fill it again and then the level settles back to about the half way point. If you do it this way you should not have oil drooling all over when you go to put it in place because the filter has a back flow prevention diaphragm in place.

I stuff a rag in under the old filter and then a couple over the radiator. I unscrew the old filter with one hand then immediately screw the new one in place. The oil on the rags are from the old filter and drool out the ported hole in the engine block and not out of the new filter. The new filter should be screwed on until it makes contact with the engine then turned 3/4 turn more. I usually have to use a filter wrench to get the last little turn out of it or to get it off. By then my hands are too slippery. Never use a pair of filter pliers on the body of the filter itself as it will absolutely put holes in it. Always grab the solid metal ring at the base of the filter if you use a set of these pliers.

Link to comment
Share on other sites

Hi Roger. Thanks for the info on this. You have answered this topic previously so sorry to ask you about it again. One thing you don't mention is how to prime the system after the oil filter has been screwed back on. I see that some recommend turning the engine after oil has been put in the reservoir and the new filter is on. Do you turn the prop a few times to get oil thru the system and eliminate air? Or, does your process of filling the filter twice with oil allow you to just start the engine and monitor the oil pressure to insure that all is OK?

 

Oh, one last question. If theoil level ends up going slightly above the "flat" on the dipstick, is this OK or is this an overfilled condition?

Link to comment
Share on other sites

Hi Dick,

 

After the filter is on and oil is back in the system then turn the prop 20 times to prime it all back up. If you forgot to pre-fill the filter (shame) then rotate the prop 30 times.

 

In a dry sump engine you can't hurt the engine or over fill it to where it can cause a problem like a wet sump. Two completely different animals. The tank has a vent line that goes down to the bottom of the cowling. If you over fill it a tad i.e. 1/8"-1/4" over the flat area nothing happens. If you really over fill it then it comes out the vent and you now have a clean up job on the belly and usually all over the ground right after start up.

3quarts, no more, no less. use part of the 3 qts. for the filter pre-fill. If you think after you have dumped in 3 qts. it's low it's lying and if you add another 3-4 oz. get ready to clean. I learned this the hard way on my first 912. Yep I had to get the rags out.

3 qts. only and that should put you at the top of the stick.

Link to comment
Share on other sites

Roger, another issue has come up regarding changing oil. I am about 15 hours away from my 100 hour inspection. My oil is looking pretty dark and I would like to have it changed. From now on, I'm going to go with the 50 hour change interval for the oil. If I change the oil now, which is 15 hours before the 100 hour inspection, does the Rotax manual say that the oil must be changed again for the 100 hour inspection? Or, can I go on an independent 50 hour oil change schedule that is not related to the 100 hour inspection?

Link to comment
Share on other sites

Hi Dick,

 

First I would like to say that oil color has nothing to do with its ability for lubrication or a function of its properties to protect. The black color of the oil is from carrying away carbon from the system and suspending the carbon. The only way to actually check an oil's true break down time would be an oil analysis. Some diesel service centers (i.e. City of Tucson) used to do the analysis and not change oil, but later found it cheaper and more advantageous to just change it at a prescribed interval.

You are better off doing oil changes at 50 hours verses 100, but I'm sure the oil would still be fine at 100.

 

You can do your plugs and oil independently from any inspection. They do not need to be tied to an inspection. Where it says to change the oil on the inspection page I usually make a little note stating when it was changed or when it is due.

Link to comment
Share on other sites

Roger, thanks for your reply and for your comments on adding a note on the inspection sheet. It all goes with the mantra, "documentation, documentation, documentation"! I'm using Mobil synthetic 4T so I figured that my change interval was good to 100 hours but something about seeing dark oil that has always bothered me. Guess I'll spend an extra $50 to $100 each year to run at 50 hour intervals. Especially on an engine that would cost $18K to $20K to replace! To keep my record keeping simple, I'll run to my next 100 hour, change the oil then and then go each 50 hour afterwards.

 

For all who read this, here's a little bit of wisdom from my friend who's a Light Sport Maintenance/Repair. Don't put off pulling the magnetic plug on your engine at each oil change. The Rotax manual allows up to 3mm of metal "fuzz" on this. Anything over 3mm, the manual says "the engine must be repaired or overhauled". By skipping a look-see at this plug, one could miss a metal buildup that's less than 3mm but when looked at the next time, it could be over 3mm and the red flag is raised.

 

 

Link to comment
Share on other sites

The magnetic plug check at each oil change is required and on the inspection sheet. If you only change oil once every 100 hrs. something could be going on that you might catch a little sooner at 50 hr. intervals. Many have been using Amsoil Motorcycle oil 10-40W or 20-50W (summer) for quite a some time now (4 years). The mag plugs I see from the people using the Amsoil are very clean. Zero fuzz of any kind. Amsoil is the least foaming on the market. It has extra additive for gear wear, but it is a full synthetic so not for constant 100LL use. The occasional tank on a trip is no big deal.

Link to comment
Share on other sites

The magnetic plug check at each oil change is required and on the inspection sheet. If you only change oil once every 100 hrs. something could be going on that you might catch a little sooner at 50 hr. intervals. Many have been using Amsoil Motorcycle oil 10-40W or 20-50W (summer) for quite a some time now (4 years). The mag plugs I see from the people using the Amsoil are very clean. Zero fuzz of any kind. Amsoil is the least foaming on the market. It has extra additive for gear wear, but it is a full synthetic so not for constant 100LL use. The occasional tank on a trip is no big deal.

 

Roger, the magnetic plug check is a 100 hour inspection item according to the checklist. There is no mention of the magnetic plug inspection in the oilchange procedures.

Link to comment
Share on other sites

Tom,

 

You may be technically correct. I'm not going to research the manuals right now to see if it specifies pulling the mag plug at anything other than the required inspections. Regardless of what the book says, which is the minimum level of maintenance required, I change my oil every 50 hours or 4 months whichever comes first. Every 25 hours if I was into 100LL which I am not.

 

Since it only takes 10 minutes (15 if you are slow like me and 5 if you are fast like Roger!) to pull the mag plug, reinstall and safety it, I do it every time. I would recommend that procedure to everyone.

Link to comment
Share on other sites

  • 10 years later...
On 9/12/2010 at 4:04 PM, Roger Lee said:

I can tell you the right way.

 

Someone ask about siphoning oil out of the tank instead of draining. DON"T. If you remove your tank and look inside you will see a baffel about half way down and the surrounding screen and the plate on the bottom. All this prevents the contaminants (i.e. lead and carbon and debris) from being taken out of the tank if you try and siphon verses draining. Always drain the tank. I don't even like the quick drains that screw onto the bottom of the tank. (p.s. they aren't technically approved anyway) I think they drain too slow to help remove all the contaminants. The prop should always be turned to hear the gurrgle prior to opening the oil system and then never turned again until the system has oil in the tank and the filter is in place. The oil should be warm when draining and if you catch a sample for an oil analysis then it should be caught about half way through the draining.

The oil filter should be pre-filled with oil. That is the preferred method. I use a little oil from one of the three quarts to fill the filter, then the level settles back down to the bottom and I fill it again and then the level settles back to about the half way point. If you do it this way you should not have oil drooling all over when you go to put it in place because the filter has a back flow prevention diaphragm in place.

I stuff a rag in under the old filter and then a couple over the radiator. I unscrew the old filter with one hand then immediately screw the new one in place. The oil on the rags are from the old filter and drool out the ported hole in the engine block and not out of the new filter. The new filter should be screwed on until it makes contact with the engine then turned 3/4 turn more. I usually have to use a filter wrench to get the last little turn out of it or to get it off. By then my hands are too slippery. Never use a pair of filter pliers on the body of the filter itself as it will absolutely put holes in it. Always grab the solid metal ring at the base of the filter if you use a set of these pliers.

As far as oil analysis. Sure it’s good practice…However, comparing the ROTAX with Lycoming and Cont. engine analysis are the readings/findings similar on a one to one comparison basis, or is ROTAX less prone to the same wear and tear ailments for any reasons. I just don’t see details in any GA maintenance periodicals about how ROTAX engines fair/wear under different conditions…?  

Link to comment
Share on other sites

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.

Guest
Reply to this topic...

×   Pasted as rich text.   Paste as plain text instead

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.

Loading...
 Share

×
×
  • Create New...