2200 oil leaks

Oil leaks in general but particularly the fuel pump.

I have had similar symptoms with my 3300 (Sonex) and I have just changed the fuel pump gaskets. BUT when I did , on close inspection

it really did not look like it was leaking. While I was under there I also noticed oil on my push rod tubes (only the aft 2 cylinders)

after cleaning it all off and desperately trying to find where it was coming from. Then the penny dropped , it was coming from between

cylinders 1 and 3. Guess what is above cylinder 1 and 3. The oil filler tube. Yes I had spilled a little bit now and again while putting oil

into the engine , it runs down between cylinder 1 and 3 gets blown back into the push rod tubes and all over the fuel pump.

I have spoken to a few owners who have (Like me) replaced their fuel pump gaskets so I am writing this to defend the humble fuel pump.

Before you do anything make sure the oil you find is not the result of spillage during a top up process.

And a little oil goes a long way when you spill it!

D.

My engine is leaking small amount of oil from the area where the oil dipstick tube is attached to the sump. I am pretty sure the leak is not comming from between the block and the sump. But is difficult to detect. The oil moves backwards in the same as described giving the area around the fuelpump an oily look.

How is the dip stick tube attached to the sump? Is it simply pushed in and kept in place by holder at the top, or does it also have a thread at the bottom to fix it to the sump?

There is also a tiny leak from the top between the two crankcase halves. Any suggestions how to stop this without the whole engine being taken apart?

Hi Olav,

The dipstick tube is pushed into the sump and an O-Ring seals it there.  It's restrained at the top support.  Assuming the O-Ring is in good condition and that there's no scratch or anything on the tube, you could disassemble it, clean it thoroughly (which will be tricky without removing the sump) and apply a little gasket sealant to the O-Ring.  You might also try to fit in an O-Ring with a bigger cross section, but chances are there won't be enough room.

Leaks between the case halves will be very hard to stop without disassembly.  You could try some Loctite "wick-in" sealant but because the joint will be oily it will be difficult to seal it completely.

Regards,

Doug.

Thanks. I will check the o-ring and replace it if needed. Can you confirm the size of it? 18.72x2.62mm.

About the leak between the crankcase halves. There is a visible dent in the seal face (I will send a photo). Looks like the seal faces were slightly damaged before assembly. I will try to stop the leak with Loctite or maybe a liquid sealant can do it?

18.72 x 2.62 will work.  We normally use Viton but Nitrile will also work.

The wick-in sealant is a thin liquid - it seeps into narrow areas via capilliary action, then cures.  It's not bad stuff, but does prefer the surface to be clean.  You might be able to clean the joint using some Aerostart or similar (nil-residue cleaners, ether based, work... Carby or MAF sensor cleaner might also work) before you add it.  Don't put too much on - it is possible for it to seep into other areas and stick things together that you didn't want stuck!

Regards,

Doug.

Hi Doug. Replaced the o-ring for the dip stick tube, and it seems to have stopped the leak. The old o-ring was flat on the inside after sitting there for 10 years. Nothing else to see.

I would recommend that you in the future make the hole in the sump a straight cylindric hole, and use a dip stick tube with a wall thickness that will allow for the o-ring to be installed in a groove on the tube. That will make the replacement of the o-ring a two minute job with no risk. The current design makes it very awkward to replace and there is a risk that the o-ring could drop into the sump while replacing it.

Regards Olav.