400HP55

Ok guys I finally had a chance to post some pics. While I am doing this, if you need a part #, let me know! I'll do this somewhat like a write up. Some cool stuff!!! We'll go in order from top to bottom...

Pic#4 - To get to the camshaft was fairly easy. I needed to order a special tool in order to get the camshaft out. Its a bit tricky cause you need to keep tension on the other camshaft. I couldn't loose the chains position on the balance shaft.

400HP55

So with the camshafts/valve train out on the passenger side its time to remove the intake manifold...

Pic#4 - Just a quick glance into the intake valves that are on top of cylinder #3, if you recall these valves were suspected to be my knocking sound, they feel and look good. Who knows how they look under. Taking off the cylinder head later will show exactly what was wrong.

400HP55

When we take the intake manifold apart here is what is inside. Its fairly complex...

Pic#5&6 - There are both long and short plenums for low and high rpms. These butterflies are open on lower RPMS and closed on high RPMS to sustain perfectly balanced airflow for all RPMS. They switch back and forth depending on RPMS. Very interesting!

400HP55

Here is most of the intake manifold system and the fuel rail and injectors. I'll be getting all of this hot tanked a restored, possibly polished. Next is the cylinder head. Stay tuned...

betrezra

Great Write up with Pics too.
Subscribing!

Jons95c36amg

The insides look clean. Not gunked.

400HP55

Ok guys take a look at this and tell me what you think!

On pic #3 - Its really scratched ....

The pistons rock when I push on them.

400HP55

Bottom of cylinder head. The cylinder that was scratched was black and the spark plugs were caked with oil...

AMG_BENZ

On the very first picture, it looks like you got a W209 engine. I don't know if that means you are using a W209 cover on the W208 motor. The picture with scratched cylinder wall, is that the one where you heard strange sound?

400HP55

You mean the air cleaner. Ya it fitted it onto the W208 - it was a challenge to say the least...

Well the noise sounded like the 3rd cylinder from the front... but after looking at this I'm thinking it was that one.

betrezra

Did leak down test show anything with cyl 3?

The pics appear cyl 3 is getting oil past the rings of the piston, looks like no spark/ignition on that cyl (oily plugs), looks like possible piston ring damage (cracked ring) scoring on cyl walls.

I'd drop that piston and inspect. If this were an old dodge slant 6, I'd run a $5 autozone cyl hone on it, and pop in a cleaned up piston with new rings and go to town...... someone more knowledgable about the star cyl walls/r*r will have to chime in on your options here.

Thanks for sharing your journey.

betrezra

http://enginemechanics.tpub.com/14076/css/14076_56.htm

blackbenzz

My money is on cracked ring land/s

PTE

You have a nice winter project. unless you have an isolated problem to just that cylinder. ( Injector) What caused that one to tear up most likely has already started to work on the other pistons. You can get 1/4 mm / .010 ths. over-sized pistons from Mahle Motorsports with the correct ring package for Alusil sleeved motors. BB you are most likely to be correct. Those series of Pistons from 01 - 03 have to much Silicone crystals and were brittle, didn't take much detonation to hammer the ring lands.
Cheers _PTEngineering

400HP55

All my cylinders were at 135-140PSI. It doesn't make sense. None were leaking. Thanks for all your feedback!!!

I was experiencing detonation I believe. So I bet thats it.

Now what to do..

betrezra

How many miles?

400HP55

91,780

blackbenzz

Those look like compression test results not leak down.

Detonation is the enemy of the motor. You think it was from your tune or a result of something else mechanical?

Depends on what you want out of the car

400HP55

Ya I meant compression. I will try leak down. I think it was because one of my coil packs failed at the same time my MAF did. Would this be the problem?

400HP55

BlackBenz you were right. Ring ate up walls.

Everything inside the engine is stamped with AMG. I'm gonna take pictures and show you guys. It's pretty cool. A lot of time went into building these AMG's. Gave me a whole different feel for what AMG stands for

I'll take pictures when I get a chance.

P.S. Those Mahle pistons look expensive..

400HP55

betrezra

So it looks like engine comes out the top VS dropping any type of k-member?

I've been curious about this for a while.

blackbenzz

Yea I always pull then from the top. Its actually easier than one would think

400HP55

Well, the easiest way is to just to pluck out the engine topside but you have to remove the radiator and all front radiator support, hoses, power steering lines, a/c lines and various other things like wiring harness and such. Thats all you have to remove. And of course the motor mounts. The tricky part is dis-mounting the engine from transmission. More pics...

400HP55

Old engine out - Then the one wrapped with a orange strap is the the one.

Heres a first start after I did all pre start requirements - no CEL's

http://www.youtube.com/watch?v=9-uM5...ature=youtu.be

Total Cost - $2800 including new oil, filter, thermostat, intake manifold gaskets, MAF, A/C Charge, power steering fluid, wiring harness swap, motor mount swap, new tensioner pulley, and a few other things.

The wiring harness in the old engine didn't swap to the new engine. The alternator grounds were different. Old one was a bolt and the new one is a clip.