Missing/sheared bolt... problem?

Bought this last week, it appears to run just fine, I removed the engine cover today to check what sort of EGR mod was fitted and noticed a bolt is missing/sheared on the top near the dip, see photo. There's some oil along the gasket underneath, which I've just cleaned off - will see if it returns after some miles.

Is this a disaster waiting to happen? Do I need to get the bolt drilled out/replaced etc?



The documentation that came with shows a new head was fitted in oct 2010.

UPDATE: My friendly local mechanic says just to keep an eye on it to see if any oil leaks, and that it's probably worth just leaving it rather than trying to mess about extracting the broken bolt from the block. Sound about right?

If its not leaking too badly I'd leave it alone. The oil under the cam cover is not at high pressure. The cover bolts are only supposed to be tightened to 7 ft/lb.

Aye cheers, had a minor panic as I know sweet FA about engines, learning as I go

Interestingly, I had another squizz at the EGR Mod this evening, the vac hose had been disconnected from the modulator and had a screw in one end but was open at the other (disconnected from anything). The modulator was still connnected to the ECU, so I guess for some time this thing has been trying to open the EGR valve and losing vacuum due to that open hose....

Anyhow, reconnected the hose and plugged the other end, and disconnected the modulator wiring.