smoking from the oil filler tube

[aljohnso]

my engine on my 1968 SIIa is smoking quite a bit from the top of the oil filler tube, the vapour is nicely rust proofing the engine bay with a layer of oil.

I suspect the rings are leaking/broken.

I get an even pressure on the cyclinders using a compression guage and do not get much smoke at all out of the back.

Is this all consistent with rings going or am I missing something more obvious (before I take it to bits)

As I only use the landy for a couple of thousand miles a year I was toying with the idea of capping off the oil filler tube and running a pipe from it down to the bottom of the engine to get rid of the vapour down there instead? Or can I even just fit a series 3 oil filler pipe and cap it off completely (I imagine not as the pressure must go somewhere)

[Tonk]

i'd suspect rings too.

i wouldn't go with your bung the holes up to fix it cos it wont last long, broken rings tend to kill bore walls quite quickly.

[rtbarton]

The SIII vents the crankcase into the induction system. Is it petrol or diesel? If diesel it may not be advisable to vent too many fumes into the inlet as you may get the engine running away, fuelled by the oil.

The best way to check for worn bores is to do your compression test and then again with a small amount of oil introduced into each cylinder. An increase in compression will indicate worn bores and/or rings.

[aljohnso]

thanks for the replies guys, any way of telling whether the rings are broken or just worn without taking the engine to bits? the problems has got worse gradually over the last year so I'm thinking it's probably wear, just want to get it through to winter so I can take it to bits and repair it proper. If it dies I guess I buy a 2nd hand engine for 50 quid and work on one while the other is in

Al.

[shinais]

capping off the oil filler tube and running a pipe from it down to the bottom of the engine to get rid of the vapour down there instead?

Run it into the frame instead! (If rust is a problem in you area)

Will a broken ring cause leakage? I thought this was caused by stuck rings?

You say you have even compression. But was the value in the normal range?

I have the opposite problem, no leakage to the crankcase, but lots of blue smoke in exhaust..

[rtbarton]

Run it into the frame instead! (If rust is a problem in you area)

..........

I'd be a bit wary of that, used engine oil contains acids as well as other nasties. I've even seen rust underneath caked caked-on gearbox oil.

[shinais]

I know, but the acid concentration is very low. I've never seen rust at the parts of the frame that is covered by leaking engine oil. These areas looks like new on my 1977, and their using salt on the roads here. Used engine oil is also popular for rust proofing.

[TEMPL4R]

It is fumes coming past the rings, but the breather system should cope with that unless the engine is badly worn. Check for blockages or split pipes. If you only have the filler cap with the gauze mesh in, clean it out.

Chris

[aljohnso]

well, I capped it off and installed a pipe down out of the lower of the engine bay and that worked int he sort term, however after a weekend away camping and a 40 mile drive each way with a full load in the landy the problem is now bad enough to warrant getting the head off and probably changing the rings.

Having never done this before I'm a bit wary (I've done it on another car though so should be ok)

couple of question that springs to mind though;

there are 2 main types of cylinder head gasket, copper and fibre. Which one is best, any makes to look out for and if so where to get them from?

how do I measure the cylinder diameter accurately enough to decide which rings to order

should I replace the bearings on the pistons at the same time or just leave the old ones in?

Al.

[rtbarton]

Regardring bore size, it should be stamped on the top of the piston (e.g +20) means 20 thou oversize. You can use a bore gauge to measure the actual diameter, this should be done below the wear ridge and along the fore-aft diameter and again at right angles. This will give you an idea of the actaul wear and ovality.

[Diff]

well, I capped it off and installed a pipe down out of the lower of the engine bay and that worked int he sort term, however after a weekend away camping and a 40 mile drive each way with a full load in the landy the problem is now bad enough to warrant getting the head off and probably changing the rings.

Having never done this before I'm a bit wary (I've done it on another car though so should be ok)

couple of question that springs to mind though;

there are 2 main types of cylinder head gasket, copper and fibre. Which one is best, any makes to look out for and if so where to get them from?

how do I measure the cylinder diameter accurately enough to decide which rings to order

should I replace the bearings on the pistons at the same time or just leave the old ones in?

Al.

With regard to the head gaskets, Fibre/composite gaskets are far superior to the copper ones. Various makes to look out for include ELRING and PAYEN.

Most of the regular aftermarket parts suppliers will have one. Just specify that you want a composite one, NOT copper and you will be fine.

Regards,

Diff