"leak" from spark plug

[oddbod]

Attempting to get back on the road, doing a few checks, oil, water etc., left my engine running for a while to warm up and noticed not sounding "right" a bit of a watery sound from the exhaust and checked around the engine and noticed oil\bubble from one of the spark plugs where it screws into the block. The spark plug is tight, what could the problem be and what will I need to do to fix it? Just at the minute I'm tired of fixing my Moggie and am hoping for a pleasant diagnosis (though I am aware this could be yet another problem that will have to wait for more time/money/energy/better weather)

[bmcecosse]

Unscrew it and check the threads - and the seating in the head... I doubt it has anything to do with not sounding right...

[mike.perry]

Try a new compression washer on the plug.
Worst case, the thread in the head is worn and needs a helicoil insert.
Do a compression test

[kennatt]

try to titghten it a bit more.

[bmcecosse]

NO! Might strip threads!! Remove and inspect.....

[kennatt]

still bet its not tight enough.whats he going to use a ten foot struggle bar,doubt you could strip the treads with standard plug spanner.Unless you had arms like a gorilla.

[JOWETTJAVELIN]

Indeed it might not be tight enough, depends who did the job. Basic plug fitting: screw in hand tight as far as it will go, it shouldn't put up any resistance, then tighten using a 14mm plug socket to obtain a gas-tight seal. Do not overtighten.

[bmcecosse]

Indeed it may not be tight enough - but remove and inspect - don't just blindly tighten it down!! How long can it take to do the check??

[lambrettalad]

tighten by hand then 1/4 turn ,no more,otherwise .............

[bmcecosse]

In case there is a mis-understanding, I'm not suggesting removing the cylinder head - just the spark plug in question!!!!!

[oddbod]

Dont panic too much, I can be ham fisted, just not normally with Spark Plugs. I checked the plugs and re-tightened, one was slightly easier to remove than the others and it was the one with the "leak" however I did find the first 2 plugs,working from the front of the engine were a good biscuit colour the last 2 very black and sooty?? The battery is now drained and my battery charger has died so I wont be able to do much with my Traveller, Barney, til later in the week. Any ideas why 2 plugs seem a good colour but 2 are sooty? New plugs or a mixture issue?

[katy]

Are the plugs all the same number?
Are you running 1 or 2 carburetors?

[bmcecosse]

Just start the engine using the handle! Swap the two plugs over....and then after a good hard run - check if the situation is still the same.

[oddbod]

Starting Handle!!!! Oh yeah of course

[oddbod]

Are the plugs all the same number?
Are you running 1 or 2 carburetors?

I'm running 1 carb, but larger than normal on ( I think) 1275 head

[bmcecosse]

It's normal for the two centre plugs to be slightly different to the two outers (because of the firing order 2134.... 1 and 4 tend to be slightly 'supercharged' by the charge flow already flowing in the shared inlet port to 2 and 3 respectively) Yours may be due to valve seal deficiency - or general wear and tear with bores/rings/pistons.

[oddbod]

I've just driven up to an old boy mechanic to have a look, its only running on 2 or 3 cylinders, he reckons exhaust valve or head gasket, will do a compression check when I get my modern back from said mechanic as my compression tester is at my lock up and I dont want to do more damage to Barney. When I got him a 1275 940g head had been fitted, do I need to know anything different to the standard manual, and will the bits ( if I need them exhaust valve, and head gasket) be different to standard?

[oddbod]

Just had a thought, could the sooted up plugs be the cause of only firing on 2 or 3 cylinders, or is that just a symptom? 2 plugs black, 2 plugs buiscuit brown.

[kennatt]

compression test is the way forwards but why not fit a set of new plugs,or two known good ones into the Black holes see what happens then.

[bmcecosse]

Almost certainly head gasket - don't run it - just pop the head off!