Oil leak
 

I have noticed oil build up around the left hand side of the engine block, just above the timing belt area. It's always been a little oily around that area but I think its getting worst. It's also a little oily underneath the air intake pipe just after the filter housing. The top of the engine is fine.

Are there any obvious common issues around this area that would show this kind of thing? I do have to top up the engine oil every 6 months or so these days

Is the swirl flap connecting rod working?

It doesn't appear to be doing anything, but I can only check whilst car is idling.

How do you check properly?

You may need a helper. When you start the engine, the arm should move. When you stop the engine, it should also move. If the plastic arm is intact (i.e. it hasn't fell off), then that's a start. Normally they break and that area can end up a sludgy mess because the swirl flaps won't be working properly.

I'd suggest giving the area a clean and keep your eye on it to see how soon it gets oily again. Its possible that the rocker cover may have a slight weep.

OK, great.

The arm is intact, in fact, I did manage to slightly move it back and forth myself by hand.

It is very oily round the arm so I think that is the problematic area.

Yep, its likely. Its common to leak around that area. Its coming from the swirl flaps themselves or the rocker cover gasket, but I suspect swirl flaps underneath the valve cover gasket. They get clogged with carbon, which turns to an oily mess. Its a big job to replace the swirl flaps, which includes;

-A new swirl flap mechanism with a new plastic connecting arm
-Take the injectors out, remove valve cover with gasket
-Remove old swirl flap mechanism and install the new one
-Put the valve cover back with a new gasket
-Install injectors and fuel lines
-Bleed the fuel system and calibrate the swirl flap motor

Big job and its costly. Being honest, its probably not worth it (unless it gets really bad).

Even if its not the swirl flaps themselves, the rocker cover gasket isn't exactly easy to replace either. You have to remove the injectors to get the rocker cover off to actually get to the gasket, then install the new one, reinstall the injectors and bleed the system. Its not a 5 minute job.

Sounds really intrusive.

I think I will clean the area up with some brake cleaner and try and prove the swirl flap is actually operating or not

The swirl flaps only work at lower speeds and idle anyway... they also help with emissions. After 1,500rpm, they don't do anything. So in effect, they could be stuck open (which can happen) and you won't see much of a difference. Sometimes that little plastic arm falls off completely, then the flaps are either stuck open or stuck closed.

Its getting stuck in the closed position that causes problems like engine management lights, loss of power, lumpy idle and fuel economy drops.

I'd just give the area a clean and keep your eye on the oil level. Make sure its getting motorway drives too, above 50mph for around 20 minutes to clear the DPF out. If the oily mess comes back, its likely just an accumulation of carbon over the years that's turning to an oily mess with heat and spreading. The only way to repair that is by doing what I explained earlier, which is costly. I reckon nowadays that would be a £600 repair.

I wouldn't worry about it. You have no error codes on the dash and I assume the car is driving fine.