E70 30D - How long for residual oil to burn off?
 

Hi All,

So I finally replaced the valve cover gasket along with the injectors seals that where leaking diesel onto the valve cover. I took it for a test drive and its smoking down from by the DPF, exactly the same as before, but as I never had any engine degreaser I didn't clean up the oil from before so I think (hope) it's just the residual oil, but how long should I expect it to continue for before taking another look just on the off chance there's another reason for it.

Here's a video of the valve cover removed and the oil residue from what appeared to have started from the back corner of the valve cover onto the manifold and further down.

https://youtu.be/VZz6-kEohIk

Here's some photos

https://i.imgur.com/fuJdhLl.jpeg

https://i.imgur.com/uGxyURa.jpeg

https://i.imgur.com/nKLtGHi.jpeg

And here's how it's smoking after replacing the valve cover



https://youtu.be/qvXef18mWnY

Shouldn't take more than a few miles to burn off. if that is not the case use some brake cleaner spray to clean the area. If it still smokes then check your work. Another option is the source of the oil wasn't coming from the area you worked on.

Hi, it's been a while since I've been able to work on the car due to family issues, but before I left I realised it was no.6 injector leaking at the return line. To understand if the smoking was possible to come from this diesel fuel I tipped some water behind the valve cover (the exact place where diesel would spill if enough accumulated) and sure enough, with the engine being on a slight angle the water dropped straight onto the DPF and surrounding area. So, this would explain why the smoke was so random, it was just a matter of time before it accumulated enough and with a steep hill or speed bump the diesel would eventually spill down the back.

Good job!

Right, the diesel leak is sorted. Took it out for a drive and fine, then took it on a dual carriageway, came back and seen this

https://youtu.be/icWHtdY8dpg

Legit confused now, valve cover has been done and from what I can see with the endoscope it's absolutely fine (from the areas I can inspect anyway)

There does appear to be oil around the head gasket, I do believe this is common to see after having a failed valve cover gasket as the head gasket has a lip.. But yeah because of the tiny amount of space I have and the heat in that area I'm struggling to source where exactly its coming from.

https://i.imgur.com/ZJDaW3c.png

https://i.imgur.com/8LXugv6.png

That looks like that exhaust flex piece mostly. Not sure how it's built exactly but it's pretty porous, right? Maybe finally being able to achieve proper exhaust temperatures is finally vaporizing what ever residual fuel or oil is still hiding. I do think it still looks like vapor and.not actual.combustion smoke. Good you're keeping an eye on it. You've done well with it so far.

That would be great if it was, however, I was monitoring exhaust temperatures when I took it on the motorway and I did see excess temperatures of 500 degrees Celsius or so. On that 35 mile run I came back with no smoke, I was really happy and assumed its all sorted. Then I did a small trip and it was smoking yet again, that's when I thought maybe the diesel fuel builds up in the valve cover and then spills over to the exhaust but then I fixed the faulty fuel return line and yet it's still managing to smoke.

I can't help but feel if this in in fact residual oil/fuel it shouldn't have been able to do a motorway run with DPF regen exhaust temps and not smoke, but then smoke like this from a small dual carriageway run.

I'll take it out later and see how things go.