Valve Cover Replacement Questions

[mnathan]

Hello all,

This is my first time doing more involved repair on my car outside of oil, breaks, alternators etc. My 2008 M35 has a habit of smoking after I turn it off, and burning oil rapidly. Starting a week ago the poor thing started shaking at idle, and displayed a P0302 code.

So, I changed the sparkplug on cylinder 2, which had no effect. I searched for a vacuum leak with a squirt bottle but was unable to find any. I decided to kill two birds with one stone and replace both my valve covers, my coils, and the remaining spark plugs since its long overdue. I am currently taking the car apart to access the covers while I wait for parts to arrive. I would like some of your expert opinions on what I have seen.

1. Ill start from top to bottom, at the upper plenum.

There is a lot of oil caked on the underside, as well as some corrosion on the bolts coming through the top.

2.Here is the lower plenum.

How bad is this? I have never opened a plenum before.

3. Here is the intake manifold

Once again I'd just like to know how bad this is, and what would be a safe way to clean it. Does it indicate any further repairs Im not already doing?

4. The fuel injector for Cylinder 5

Oddly enough the rest were clean. This really isnt that much oil, but I am curious why there could be such a small amount.

5. Coil for cylinder 6 was very full of oil. I couldn't get a good image of this, but I'm hoping just the replacement of the valve cover will fix this.

That;s all I found so far. Unfortunately amazon said they delivered my parts but I never saw them so I am waiting for replacements. Let me know what yall think. Due to my regrettable finances I wasn't able to afford Z1 valve covers, we're stuck with MITZONE. Any advice about the repair or anything else you see is greatly appreciated.

Thank,
mnathan

[VStar650CL]

My guess would be most of that oil crud is coming from a bad PCV Valve or a problem in the inlet side of the PCV plumbing. What does the smoke after shutdown smell like, and what color is it? If it's white and smells chemical, there's a good chance your #2 injector is leaky.

[mnathan]

My guess would be most of that oil crud is coming from a bad PCV Valve or a problem in the inlet side of the PCV plumbing. What does the smoke after shutdown smell like, and what color is it? If it's white and smells chemical, there's a good chance your #2 injector is leaky.

The PCV valve is on the other end of the tube that I disconnected from the lower plenum, right? That tube looked pretty clean, and I didn't see any mess around that valve. Believe me it took 10 minutes to get it off lol.

Smoke after shutdown often smells kinda like oil. Its white/gray. I often notice it at night infront of my passenger side headlight. I'm not so sure that the #2 injector is leaking. I just got to the injectors today and the only injector that had any mess was #5 like in that image. The others looks perfectly clean.

I will say there was a lot of oil coating the valve cover on the driver side, which could be related to that #6 coil well (not sure what that little tunnel it occupies is called) being full. Ill add an image I took before I removed everything below. It kinda shows how much caked on oil there is on the driver side valve cover.

To help frame what you're looking at, coil for cylinder 2 is just outside of the image on the right side. Coils 4 and 6 are in frame.

*edited to add a clarification about what is shown in the image*

[bicsintegra]

I have done a couple of plenum jobs on M35s and G35s and yours is quite dirty. I would also agree that it is the PCV valve, change just for kicks, they are not expensive. if the issue persists you may want to look into a catch can. but first change the valve covers and the gaskets this may fix the oil issue, but change PCV valve with this maintenance.