Oil Return Tube

[tbsmith]

Me again My car has a few oil leaks I haven't tracked down, but there is one I can see, and that is the oil return tube. It continues to leak from the tube (slowly) days after turning the engine off, which as I gather from searching the archives means it may be blocked.

Is this a common occurence? How dangerous is it? In other words, could the sump be starved for oil or are there other return paths?

The tube feels like it is made of rubber - do you think it will flex enough to remove without pulling the head? Any ideas for clearing it out and stopping the leak?

Tom

[types26/36]

Yes its a common source of leaks, it is rubber and they go hard and brittle with age. There are other oil return paths e.g. down the timing chain chest so the engine will not be starved of oil but it is a bit of a pain and makes a mess.
It can be replaced without removing the head, usually easier to remove the carbs, break and remove the old tube. A new one can be forced into place as they are reasonably soft although some people heat them first in hot water to make them more supple, never had to heat them myself but would if nessesary. Just a note, once in place rotate it to make sure it is located correctly and I also use a silicone seal on the locating faces.
Its a while since I did one, think I also took of the fuel pump but its late and I've got memory fade

[garyeanderson]

Hi Tom
My friend Bill Fralic and I were talking about this the other day. Yes it can be done with the head in place, no I will never do it that way again, it is not worth the aggravation and foul words that seem to emanate from the orifice some people call there mouth. I sure there are other reasons to remove the head, replace water pump, replace timing chain, all relatively low dollar items that can give you peace of mind when your more than an hour away from home. You can tempt fate but with a Lotus and fate seems to win a lot and then people sell them for much less then there worth and bad mouth them the rest of there lives. Just my 2 cents worth.

Gary

[1964 S1]

Provided you're not suffering from abnormal blow by (excessive crankcase pressure,) you may be able to stop the leak by applying silicone sealant around the round ends where the rubber meets metal. As mentioned, old rubber goes bad but if it's not leaking terribly bad a patch fix may last for years. I personally would not remove the carbs and fuel pump to repair an oil leak unless it was totally necessary. Get the car up on ramps so you can see things from below and above. Wipe the area dry, start the car and then try to see exactly where the leak is.... IMHO Eric

[ppnelan]

...Or you could just just enjoy the fact that your chassis should not rust with this 'automatic lubrication system'... I thought most Twin Cams usually came with this as standard ?!

Matthew

[tbsmith]

I get enough oil on the floor overnight to make a 4-5" puddle so my garage floor will stay nice and rust free as well.

Thanks for the suggestions. I will try an in-situ fix with sealer first.

Tom

[Tonyw]

Hi guy's, just a thought that might be of use. When you are looking for a 'slight" leak clean the engine really well and run it up until warm/hot, shut it down and wait a while then puff some talcum powder around all of the suspect areas, the powder will turn dark where the leak is, your engine will smell like an Australian brothel.

But of course most leaks being so prolific will be able to be seen from the space shuttle.

Tony W

[types26/36]

I I will try an in-situ fix with sealer first.Tom

Bodge! Bodge! Bodge!

Dont waste your time it will still leak just fit a new one without taking the head off......its really not that difficult.....treat it as a challenge

[tbsmith]

Brain,

It seems it wasn't so easy for others to do:) Nevertheless, I did the deed and poured some goop on it so I will know in a day if it did any good. If I can buy some time before doing it right, I don't mind. I will be ordering the part regardless for a proper fix.

Thanks,
Tom

[RotoFlexible]

Bodge! Bodge! Bodge!

Yes?

(Maybe we should have gone with the Porsche instead of the Lotus in '67)

Andrew Bodge a/k/a RotoFlexible

[types26/36]

Brain,
It seems it wasn't so easy for others to do:) Nevertheless, I did the deed

Brain! ...Brain!....oh yes I like it
....and Andrew (Rotorflexible) ......what can I say...

[RotoFlexible]

....and Andrew (Rotorflexible) ......what can I say...

No worries! When my father did business in the UK in the 60s, some people he met had difficulty maintaining the stiff upper lip.
Still, if I ever sell the car, I'll need to provide complete photo documentation to demonstrate that I've done things correctly

[tbsmith]

Wow, I can't believe its been 6 years since posting my original question and living with an oil leak that long. Anyway, I had the carbs off recently and decided to replace the oil return tube at the same time. The job wasn't difficult at all. I just made sure the openings were oil free then used a rubber-suitable sealant (I used a Permatex product called High Tack Sealant before re-installing the new one. Silicone based sealants don't generally stick to rubber well).

So far, so good. After a few test drives, the area is dry as a bone. I would not try to do this with the carbs in place though.

Tom

[billwill]

For the record:

The conical rubber pipe is not the mail oil return, merely the return of condensed oil from the top rear right corner of the cylinder head, which is a condensation chamber.