Amazon: Wee bit of smoke......

[48pop]

Hi folks,

Have a wee whiff of smoke, oil fumes from the breather on my '66 122s...Nothing major but is this something I need to be planning to attend to in the future?

Its a daily, starts on the button every day and still has the ability to surprise other commuters

Cheers
Gerry

[Derek UK]

Which breather? Has this started suddenly, like after a fast cross country thrash? You might have broken a ring.
A critical clean up of the breather system is a good idea, including the nozzle in the inlet manifold and the filter in the top outlet on the dizzy side teardrop.
Post a pic of your engine bay showing your breather system. Many cars end up with a mix of the B18 and B20 systems and some of these don't work properly.

[48pop]

Had another look.....Its mostly coming from the the pipe on the dizzy side, underneath the engine....Never noticed this before

[Derek UK]

That looks cleaner than many! Not much in the way of oil leaks. If that is a '66 engine the rocker cover is an earlier one with the filler in the middle. No problem. This type of engine doesn't have a recirculating breather system so all you can do is to make sure the mesh in the filler cap is clean and the bottom tube is clear. Side pipe is held on by an awkward to get at bolt underneath the teardrop. If the bottom one is blocked it will puff out a lot of air from the top with the cap off. If you get oily smoke out of the bottom all of the time it's likely your rings are getting a bit tired. A compression test would be a good idea. It used to be common to drive along behind "old" cars and see the smoke being pumped out of the breather under the car. Rare now with recirculating breather systems. Don't worry. If it runs alright, goes alright and doesn't choke your MOT man when he's underneath, it'll probably be fine for many more thousand miles yet. B18's don't die easily!

[Steve121]

I have the same breather settup, when the engine broke a ring the breather pipe was like a second exhaust pipe!

[48pop]

Hmmm....How does one test for a broken ring......? Big job? Engine out?

[TomTom]

Correct me if I'm erring, but I believe the only proper way is to get the engine out. The 10+ hours to get the engine in and out has always stopped me even going there, but rather following Derek's advice to just carry on with what you've got. The compression test may go some way to answering the question but then again may not show anything untoward (remember it's the variance between the figures that counts, not how far the numbers go. My heavily used B18 used to get around the 150 mark but only showed a 2-3% variance between the 4 cylinders. But it still choked the odd by-stander in supermarket car-parks, much to my embarrassment.

Tom

[Derek UK]

Get the compression test done first. Close numbers for each cylinder is more important than high, as per the book, figures. Say you got 115/120/110/105. That would be low but even meaning that the ring to bore clearance was getting a bit loose. If the bores and pistons/ring grooves looked fine you might be able to just fit new rings of the same size. If you got 120/80/110/115 the 80 one might indicate a broken ring. It might also mean a burnt exhaust valve but that would likely show as a smokey exhaust rather than a smokey breather.
Post the compression figures if you can.

[Steve121]

wot derek says. A compression test will tell you, mine had a very low reading indeed on the broken ringed piston. Or even a leak down test by a garage, though you can make one of these cheaply if you already have an air compressor.
Certainly no need to take the engine out.

[48pop]

Well the weird thing is.......Had another look under after a run today and can't see anything from the pipe now....

Guess I can live with it for now