M-Theory

So after deciding to do some maintenance before throwing a nitrous kit on this spring:

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.

BLKROKT

Nice work, thanks for sharing. Have any better pics of the intake manifold with the sludge in it? I've been considering doing this as I installed my Weistec catch can last winter but never cleaned the intake first (as I probably should have). Plus I have a set of phenolic spacers here and am debating whether or not to put them on. Anything especially tricky to keep in mind when taking it off - seems pretty straightforward.

M-Theory

Unfortunately I don't have any pictures of the inside of the manifold, thought I took some but I guess I got caught up in cleaning and didn't.

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?

BLKROKT

Yup, I have the Renntech PDF also to use as a guide for whenever I do it.

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.

jptaylor

When I took mine off it too was FULL of sludge...mine had the consistency of burnt honey...it was damn near impossible to get it off and he's right about the fingers being sore part....but like he said when I got mine back together it was a different animal.....having run catch cans in the past and seeing what they do there is no doubt that the m156 NEEDS a catch can, but at the same time you are not really doing your engine justice if you don't go ahead and clean out the manifold...

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

jptaylor

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

BLKROKT

Well I guess that settles it. Definitely taking mine off for cleaning. Thanks.

m a x i m u s

Weistec told me that eventually the oil deposits would burn off...

jptaylor

Max I will say this and not even bat an eye, there is no way in left Hell that what was in my manifold would have ever burnt off, not even if you threw the manifold in blast furnace......I would bet anyone that has had a catch can installed who pulled their manifold would find it sludged up still, no matter how many miles had passed.

M-Theory

Yea I have to say that the amount of oil I found would have never burned off, it would have just gotten worse. I plan to buy a catch can and pull the manifold again before installing it and doing a thorough cleaning to get the full benifit of the catch can.

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.

m a x i m u s

Thanks, guys. I had installed my can, and then had to have the intake pulled for something after it. My mechanic told me it was pretty oily and that he had wiped it down. To what extent, I dunno, but from what you guys tell me, I'm guessing he didn't put a ton of elbow grease into it. Probably just wiped off what could get easily wiped off. Next time the intake needs to come off, I'm gonna lay my eyes on it and have him clean it all the way, maybe even in a parts cleaner.

ritalin

When i had my 335, i used meth injection and after 47,xxx km my intake and head were spotless.
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.

m a x i m u s

I was wondering about sea foam as well, but I read some others saying it was a no-no with the m156.

jptaylor

I seafoam about every 10k miles or so and it works WONDERS....
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....

M-Theory

I've never used sea foam before, when you got to the part about dunking the hose straight to the bottom and killing the car I wasn't sure if you are joking or not?

Either way I'll have to try this if it does a good job and cleaning carbon like everyone says.

jptaylor

When you dunk it to the bottom it ingests a LOT of seafoam at once, killing the engine BUT covering the entire upper valvetrain with a LOT of the cleaning agent.....the hour you let is sit is so that it can soak and loosen all of the topend gunk

M-Theory

Anyone know the parts number for:
-crank sensor
-Cam sensor

update: changing these seems to make a huge difference as well.

Celicasaur

I love this type of enthusiast DIY work.

Glad it's helped and thanks for sharing. I think I'm going to give my M156 some TLC like this soon....

Phil Chow

Interesting.

Guess I will tackle this along with the Weistec Catch Can shortly then.

YvngGold

bumping so i can do this. awesome diy

tasteofpower

how did you remove the manifold? was it hard?