Oil Leak Somewhere?

[stephenpolhill]

Hi, I seem to have an oil leak somewhere but can't find the issue. It is slightly 'wet' with oil under the cylinder head on the spark plugs side but also from the rocker cover to the rear. On the carb side its wet all down from the head.
I drive 15 mins to work everyday at 50-60 ish but seems to use half its oil roughly a week. It passed the MOT yesteday with the oil leak being an advisory.
Does anyone have a list of places/things I could check to find where this is coming from. The engine was rebuilt last year and was alright on oil...
Thanks, Steve

[d_harris]

So, just to confirm. The oil is above the line of the spark plugs? And there is oil down both sides of the engine?

That to me points to the rocker cover gasket needing replacing. Very easy to do

[chrisryder]

reads to me as leaking below the plugs on the plug side and above the manifolds on the exhaust side. which would be rocker cover gasket for the exhaust side leak, but leaking below the plugs sounds like head gasket to me. although iirc i thought water runs nearest the plug side of the head...

could be an idea to take the rocker cover off (you'll be doing that to change that gasket anyway) then you might want to check the torque of the head nuts. if you've got a torque wrench (or can borrow one) set it to about 40Nm and try to tighten each one. if it clicks without turning the nut then they are torqued to over 40Nm. Then repeat with the wrench set to 45. If they are turning and not clicking the wrench, then they're not as tight as they should be. Tighten them up to 45 gradually, and in a circular pattern (looking above the head, starting in the middle and rotating outwards).

[chrisryder]

like so!

[frame][/frame]

[bmcecosse]

That's not enough torque......... 40ft lbf = ~55 Nm and in fact the head can be safely torqued to 45 ft lbf = ~ 59 Nm. Torque in stages - so get all at 40 ft lbf and then wind up to the higher figure.
The leak is probably the rocker gasket - but could also be caused by pressure in the engine pushing oil out just about everywhere. Make sure breathers are clear and one connected to the side inlet on the carb - or less efficiently, to the air filter.

[simmitc]

Oil dripping from the front of the rocker cover gets blown down the side of the head under the spark plugs due to the air coming from the fan. Use Jizer to clean away all traces of oil, wash and dry the whole are, then go for a short run. A light dusting with talcum powder will show if the oil ic coming around from elsehwere. If no sign, then it could be coming from the head. Always worth checking the torque anyway.

[stephenpolhill]

Wow. Usual fantastic response as always.
I will have a look at cleaning the breathers now - I have fitted an oil breather pipe to the rocker outlet so ill check that for anymore goop.
If they're clean, ill do those check and look at changing the rocker cover gasket

[chrisryder]

That's not enough torque......... 40ft lbf = ~55 Nm and in fact the head can be safely torqued to 45 ft lbf = ~ 59 Nm. Torque in stages - so get all at 40 ft lbf and then wind up to the higher figure.

ooops, meant lbft!