Valvetronic gasket

[Simiewimie]

Hi.
Just noticed some smoke coming from under the bonnet after I pulled up to some traffic lights. Stopped after 5 seconds or so, so assumed it was oil burning off. Got home and checked the engine for leaks, and I think it is the valvetronic gasket. I only had the rocker cover gasket replaced a couple of months ago, and from looking at where the oil is I think that's where it's coming from.

I guess I'm here hoping for somebody to confirm my thoughts after looking at the picture...

IMG_5520.jpeg (207.29 KiB) Viewed 364 times

[jetrep]

It's a bit difficult to say. The valve cover is pretty filthy. I'd wipe it down as well as you reasonably can then drive it some more and keep an eye on it. I think it's common to replace the valvetronic motor when replacing the valve cover gasket. The photo makes it look like the oil fill cap may be leaking. It also looks like the seal around the eccentric shaft sensor may be leaking....this is another seal that should have been replaced when the valve cover gasket was replaced.

[Simiewimie]

It's a bit difficult to say. The valve cover is pretty filthy. I'd wipe it down as well as you reasonably can then drive it some more and keep an eye on it. I think it's common to replace the valvetronic motor when replacing the valve cover gasket. The photo makes it look like the oil fill cap may be leaking. It also looks like the seal around the eccentric shaft sensor may be leaking....this is another seal that should have been replaced when the valve cover gasket was replaced.

Good idea. The more I look at it the more I think maybe it is the oil cap. Will give it a good clean up this morning and monitor.
Thank you, jetrep.

[Z4Mariner]

Get out your inspection flashlight and check carefully down below the Valvetronic motor and gasket. If it is leaking, oil will pool there. The advice to clean and drive is good, but the area you need to clean below the Valvetronic motor is hard to clean. Sop up what you can, drive, and see if it fills up again. The motor usually does not need replacing at reasonable miles, just the gasket.

The ESS (Eccentric Shaft Sensor) seal should be checked - carefully remove the connector and be sure there is no oil in the electrical connector portion of the sensor. If it's dry, but there's oil seeping past the seal in the valve cover (after your clean-and-drive), then you have decisions to make about the sensor and its seal. The seal is cheap, the sensor is expensive, and replacement of either is a "valve cover off" (at least for me on my 128i convertible last year).

Good luck, and share what you find.