[wallacelau]

Hi guys,

I have a 2008 e92 328i (n51 motor). I recently smell a slight oil burnt smell inside the cabin when cold start, this usually last about 3 minutes then goes away. Do you guys think there is an oil leak? Everything seems fine except for the 3 minutes smell from the cabin vent when cold start.
I had my vcg replaced 1.5 years ago when I bought the car. I had a mechanic checked few weeks ago and he said there is no oil leak.

What do you guys think?
Thanks.

[Dan Bilzerian]

I would do your own little visual inspection and see if you can spot anything.

[wallacelau]

I took 2 pictures from the engine bay. Im not sure if its a leak or the mechanic didnt clean up for me last time when he changed my vcg.

Thanks

[E91 M Sport]

It's hard to tell from your pics but that oil does look pretty old (covered in road grime).

Another potential leak area is the valvetronic motor seal. When it leaks it pools into a nook on the valve cover so it's not very obvious to spot unfortunately (you have to remove the motor to know for sure). I found out mine was leaking when I cornered hard left and the oil was getting thrown onto the exhaust manifolds and smoking pretty bad (not to mention very embarrassing).

[Stupenal]

Your pictures don't show much of the mating surface between the valve cover and the block. The last picture where that rectangular plug with 2 wires coming out of it - to the left of that is a valve cover bolt and the only visible area of the engine to valve cover is. That looks decently clean, but you'll need to inspect that plane around the entire valve cover to see if your vcg is leaking.

My guess also goes towards the valvetronic gasket - I just replaced mine because it was leaking a good amount of oil. It formed a pretty deep pool underneath the valvetronic motor, enough to completely cover the last 10mm bolt.

Easy for you to check with the engine cover removed. Once the engine cover is removed, feel under the valvetronic motor and if you feel oil, then you've found your leak. You can change the valvetronic motor gasket without removing the valve cover.

[Eddien123]

Had the same issue. It was VCG. When the car sits the oil drips onto the exhaust and the head from the start up burns it off. Once it's burned off it stopped. After I changed it it pretty much stopped there.

[wallacelau]

Thanks a lot guys! I am taking it to another mechanic for an inspection tomorrow morning.

[Dan Bilzerian]

Originally Posted by wallacelau

Thanks a lot guys! I am taking it to another mechanic for an inspection tomorrow morning.

Yeah, let us know what the problem was if there happen to be one.

[wallacelau]

Hi guys,
I had my mechanic checked the car and he said the oil is leaking from top to bottom. We have to change the valve cover gasket, oil filter housing gasket, the spark plug and also the thermostat hose. The oil leaks to the thermostat hose and damaged it. I forgot why the spark plug too tho.

[Eddien123]

Originally Posted by wallacelau

Hi guys,
I had my mechanic checked the car and he said the oil is leaking from top to bottom. We have to change the valve cover gasket, oil filter housing gasket, the spark plug and also the thermostat hose. The oil leaks to the thermostat hose and damaged it. I forgot why the spark plug too tho.

Glad you figured it out! Good luck with everything.

[Three_thirty_I]

And this time give the engine bay a good clean around those areas where it has been leaking. It will make it easier to spot future leaks and also reduce the chance of unpleasant odours from a hot engine with old dry gritty oil patches.