My Tractor Forum banner

1 - 20 of 30 Posts

·
Registered
Joined
·
233 Posts
Discussion Starter #1
Hi all, I'm still trying to figure out the oil blowing up the dipstick on our 318. I had replaced the seal at the engine block for the tube, a year or two ago but it is leaking again now. Would this cause the oil to come so far up the dipstick? I am also wondering what you all may do to seal the tube better in the block. It seems the seal doesn't work too well or at least not too long before leaking. Thanks for any help now and in the past.
 

·
Parts collector
Joined
·
3,420 Posts
It sounds like your breather is clogged or you have bad rings.

Clean the breather out and go from there.
 

·
Registered
Joined
·
1,192 Posts
If oil is pushing out of the dip stick tube, sounds like there is excess pressure in the crankcase. Possible sources are, clogged breather tube. Check this first as it is the easiest to fix by cleaning and reinstall. Bad rings allowing combustion pressure past the piston into the crank case. Perhaps a compression test will confirm or eliminate this possibility. Over filled oil. This may be something to consider. This can also come from fuel leaking from the carb, into the crankcase. You can check by smelling the oil. If it smells like gas, look to the carb leaking gas.
Hope some of this helps ID the cause, and whatever the cause is, that it is easily fixed.
 

·
Registered
Joined
·
233 Posts
Discussion Starter #4
Thanks, I already checked the breather and cleaned it. I am trying to figure out how to seal the dipstick / oil fill tube as well. I think it my be over pressured alright but with the tractor just sitting for a day or so, it leaks at the fill tube base. I will try a compression test when I get a chance. Thanks for the help.
 

·
Registered
Joined
·
1,192 Posts
I've seen both O rings and just press fit tubes. If it just leaks at the base, when not running, then pull the tube and inspect the end. If O ring, replace it. If press fit, be sure it is not out of shape. I had a press fit leaker and just cleaned it real good, smeared some
RTV silicone around it and reset it. In all cases, there should be support of the tube to prevent wiggling loose from vibration.
Any one else have a thought?
 

·
Premium Member
Joined
·
2,609 Posts
Is it a p218 or b43g? The b43g does not have the o ring/sleeve. It is pressed in.


Sent from my iPad using Tapatalk
 

·
Registered
Joined
·
233 Posts
Discussion Starter #7
It is a 218, it has a stepped seal. I replaced it today. Sitting after filling with oil again, it seems to be dry at this point. When I went to replace the seal the one that was there was bad enough the tube fell out of the block as I loosened the support. I had replaced it not all that long ago but the new one fit much tighter than the old one ever did. I hope this will correct the oil leak. If there is a better way to help seal the tube, I be very happy to try any ideas. Thanks again for all the help.
 

·
Registered
Joined
·
936 Posts
It is a 218, it has a stepped seal. I replaced it today. Sitting after filling with oil again, it seems to be dry at this point. When I went to replace the seal the one that was there was bad enough the tube fell out of the block as I loosened the support. I had replaced it not all that long ago but the new one fit much tighter than the old one ever did. I hope this will correct the oil leak. If there is a better way to help seal the tube, I be very happy to try any ideas. Thanks again for all the help.
I get into situations like this (oil leaks plus other things) when mail ordering parts and stuff such as seals on-line. Usually what I determine is the replacement parts are clone parts, not OEM and I've even had oil seals that would not even seal a non rotating shaft at rest. (and I could not tell they were not correct size as stated replacement parts until after I had installed)

Welcome to the clone world.:tango_face_sad:

V-belt replacement for lawn tractors is another sad thing when they are not the correct stated advertised size from a vendor.:tango_face_plain:
 

·
Registered
Joined
·
1,068 Posts
A slight/small seep leak at the base of the oil fill tube on a P218 where a seal is used, is kinda normal. The o-ring at the top of the screw in check/fill stick is important - be wise to check and/or replace that too.
 

·
Registered
Joined
·
233 Posts
Discussion Starter #10
Thanks, I did replace the O ring on the top of the dip stick. I am not sure I got the correct one though. The original tube bottom seal came from Deere. It does not mean that it was the correct one though. We used it to mow the lawn today with the new seal in place, The engine seems to be dry at this point, This is much better than what I am used to. Thanks for all the help. I hope this solves that problem. I still need to check compression and find trans. leak but that is another day. Thanks again, everyone.
 

·
Registered
Joined
·
936 Posts
A slight/small seep leak at the base of the oil fill tube on a P218 where a seal is used, is kinda normal. The o-ring at the top of the screw in check/fill stick is important - be wise to check and/or replace that too.

I've never seen such but I've heard rumors that a bad dipstick oil seal on a onan 318 engine can cause it to puke sump oil into the breather/carb.
 

·
Registered
Joined
·
3,918 Posts
On my last Onan I had to replace the bottom seal and I learned something while doing it. I learned that the best way to put it in is to put the seal into the block first then lube the pipe and seal and force it in. I tried to put the seal on the tube first but could never get it to seat properly. The top "O" ring is critical to keep oil from coming out of the tube. One way to test if it is the correct ring is to lay it into the top of the tube and see if it is tight. If not then you either need a fatter one of a larger diameter one.
 

·
Make Better Mowers
Joined
·
2,075 Posts
Shouldn't the oil level at rest be below the dipstick tube?
 

·
Registered
Joined
·
45 Posts
Call Robert Kummer at 651-437-2826 he is the onan guru and he will lead you to a solution to your problem, he also has the parts that you need . I had the same problem with my p218. Now if the oil is climbing the dipstick when you check it after it sits for a few days, that's ok, mine is always half way up the stick everytime I've check mine. I have heard that it's caused by the engine cooling off and pushing it up. But call Boomer, Robert's nickname and he will fix you up.
 

·
Make Better Mowers
Joined
·
2,075 Posts
When I replaced the seal on mine the oil level was below the bottom of the tube. I never had any oil leak when it wasn't running.
Got me thinking overfill.
 

·
Registered
Joined
·
233 Posts
Discussion Starter #17
At full on the dipstick the oil is an inch or less up the tube, at least on this engine. I am still waiting to see if it leaks yet. I left the dipstick up just a little, to see if the oil crawled up. There was no oil on the dip stick other than the level when I pulled it after mowing.
 

·
Make Better Mowers
Joined
·
2,075 Posts
At full on the dipstick the oil is an inch or less up the tube, at least on this engine. I am still waiting to see if it leaks yet. I left the dipstick up just a little, to see if the oil crawled up. There was no oil on the dip stick other than the level when I pulled it after mowing.
Is that engine level???
 

·
Registered
Joined
·
3,918 Posts
I would check to see if you have the correct dip stick. I had one engine with the wrong dip stick and it had to be marked to show the real full level. On most engines, the oil is in the pan, not above it. Without changing the filter, I would drain the oil and then refill using the engine specs. Then check to see where it comes to on the stick. As Mo said, make sure it is level.
 

·
Make Better Mowers
Joined
·
2,075 Posts
Yes, I've heard of incorrect dipsticks before. It happens. How many owners do you suppose that machine has had. When you purchased it, where was the oil level?
 
1 - 20 of 30 Posts
Top