Removed Intake manifold: Catch Can & oil change importance photos
I know it's a E but it's M156 related.
(2007 with 77k miles on it for reference).
-New-
-Spark plugs
-Filters
-Intake manifold gaskets and bolts
-PCV
- MAF cleaning (I couldn't find new MAF's with out purchasing the air boxes with them)
I got the intake manifold off and to my horrible surprise my runners were oil/sludged heavily. As you'll see from the pictures I couldn't believe it. I change my oil every 4-6k miles so I'm suspecting the PCV was bad or the previous owner didn't change the oil as often as they should have. The car did idle rough at times but I've read the M156 does that.
So I spent hours cleaning each runner out until no oil was present or as much as I could. Used MAF and throttle body cleaner as it evaporates fast. My fingers still hurt from all the cleaning but it was damn worth it!
I was going back and forward on buying a catch can but this has made it a 100% need in my book for this motor.
In the end I got it all back together took it out for a drive the next day and it feels so much better from cruising to pulls, smells less also (I'm Longtube and decatted). The idle is smoother as well.
After fighting connectors and weird German excuses for worm claps etc... Manifold off!! Also you can see back there why the PCV is so hard to get to when changing with the manifold on.
Off dirty and oily inside
... I was able to pour oil out of it while cleaning it. Sucks!
Another PCV breather photo.
After cleaning, much better for air flow!
The horrible sight I saw when I got the manifold off, all 8 of them were this bad and the manifold even worse.
All done and back together. There's something about finishing a DIY project that feels worth it, even after all the cussing and fussing.
Last edited by M-Theory; Jan 30, 2016 at 03:39 PM.




But the inside of the manifold was much worse than the picture shown, it was way more caked on and tougher to get off, while also being down deeper.
It's pretty straight forward but involves a lot of disconnecting, maybe 20 connectors in all, but still nothing major. I used Reentechs PDF for their upgraded throttle body install and it has step by step pictures and notes of everything you need to do.
What would the phenolic spacer be for/do?




In theory, the phenolic spacer is an insulating material about 1/8" thick that isolates the intake manifold from the heads, preventing it from heating up through thermal conduction. I've heard mixed reviews, but got them for next to nothing so I figured I might try it. Supposed to keep the intake much cooler, we'll see.




As for pics of how nasty the manifold itself gets I thought that I posted pics of mine when I cleaned it several months ago, I'll see if I've still got them




You can see that the runners above the valves are relatively clean
Its hard to see inside but it is this wet, sticky sludge from top to bottom
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I feel that with the catch can yes the small amount of oil that slips by will burn off, but with out it there's no way even in hell this manifold would burn any oil off.
A few other e90post members used seafoam successfully.
Im curious how either would perform here.
I would love to try meth injection on this platform.
Just dont have the right shop to integrate it over here.




just make sure you do it properly
Crank car
Disconnect vacuum hose at brake booster
Let vacuum hose SIP out of the seafoam can a little at a time so that the engine doesn't stall
Do this until you have used half the can
Let the engine level out and then DUNK the hose all the way to the bottom of the can
The engine SHOULD die-you WANT it to choke out!!!!
Once it chokes out reconnect the vacuum hose, turn off the key and let it sit for around an hour.
After an hour crank car, find a dark stretch of road and BEAT THE **** OUT OF IT!!!!
your exhaust SHOULD look like one of the old mosquito trucks-HEAVY smoke everywhere!!!
This will stop and remember the smoke is ALL the carbon and sludge blowing out..
You may get an O2 code but should clear itself after several miles of spirited driving....
just make sure you do it properly
Crank car
Disconnect vacuum hose at brake booster
Let vacuum hose SIP out of the seafoam can a little at a time so that the engine doesn't stall
Do this until you have used half the can
Let the engine level out and then DUNK the hose all the way to the bottom of the can
The engine SHOULD die-you WANT it to choke out!!!!
Once it chokes out reconnect the vacuum hose, turn off the key and let it sit for around an hour.
After an hour crank car, find a dark stretch of road and BEAT THE **** OUT OF IT!!!!
your exhaust SHOULD look like one of the old mosquito trucks-HEAVY smoke everywhere!!!
This will stop and remember the smoke is ALL the carbon and sludge blowing out..
You may get an O2 code but should clear itself after several miles of spirited driving....
Either way I'll have to try this if it does a good job and cleaning carbon like everyone says.




-crank sensor
-Cam sensor
update: changing these seems to make a huge difference as well.
Last edited by M-Theory; Feb 7, 2016 at 01:50 PM. Reason: resolved


