04S600AMG

Ok, I'll cut to the chase. When it's cold all cylinders fire and there is normal power. When it gets warm the engine starts to slightly vibrate and after a few minutes "Check Engine" light comes on. Checked the codes and I got a PO307, cylinder 7 misfire. I have replaced the following:

1. All spark plugs (Test drive, no difference)
2. Both coil packs (right bank as a precaution)(Test drive, no difference)
3. All 4 02 sensors (Test drive, no difference)
4. Check fuel pressure (just for grins) (58 psi all day long) Still no difference

I am figuring there are basically only two things left but I want your opinion.

1. Fuel injector or wiring for cylinder 7
2. Ignition transformer.

What do you think?

Thanks,

wallyp

Get the engine up to operating temp and do a compression test on 7. That will eliminate any possibility of valve problems, etc.

fxdeebee

swap injector 7 to another cylinder, see if the misfire follows the injector( injector bad ) or if 7 still missing ( bad wiring ).


Assuming the ignition transformer feeds the entire coil pack for that respective side, wouldn't think your misfire would be confined to a single cylinder(?)

04S600AMG

Update.


About 20,000 miles ago I replaced the spark plugs with Autolite Laser Iridium plugs instead of the NGK Mercedes replacement plugs to save some money. I had an extremely hard time re-gapping the plugs as the anode was VERY hard to bend. I have gapped and installed hundreds of spark plugs in many different vehicles so I think I am qualified to say these were not typical. Well after I started having the misfire problem I finally got to the point where I removed the spark plugs and saw the anode of one of the plugs in cylinder #7 had completely snapped off and destroyed the cylinder, (65psi vise 190 psi of a good cylinder). This turned out to be the issue with my misfire. So I decided to remove and replace the engine with a used engine. I was very fortunate to find a V12 BiTurbo out of a 2004 SL600 which had been in a very severe rear end collision and only had 48K documented miles on it. Better yet the engine and shipping only came to $2,000.


Well I have made some serious progress. I won't even try to list everything I had to do to remove the old engine. Suffice it to say, it was a butt ton of stuff. However I did put every nut, bolt, fastener into zip lock bags with a complete description of what it is and where it goes. Some of the more notable things that were difficult and worthy of mentioning are the exhaust pipes, drive shafts, and transmission.

Here is the engine I bought off e-bay for $2,000 with free shipping.





It was in great shape and had awesome compression.

The only damage was a broken oil filler cap. This was easily replaced with the one from my original engine.




Disconnect the battery first however you should know that it will have to be periodically connected to be able to move the shifter so you can remove the shifter linkage later. When you do reconnect it, make sure you either haven't removed the fuel line to the engine or have the fuel line going into an empty soda bottle unless you want fuel sprayed all over your engine compartment. Ask me how I know this.

There were a bunch of hard lines under the trans that had to be disconnected. One thing you must know is that all fluids need to be removed from everywhere before you start. Engine oil, trans fluid, intercooler fluid, ABC oil, power steering fluid, Freon, everything.










I decided to go by the book and remove the transmission before the engine however reinstalling the transmission after the engine was put back in would have been nearly impossible so as you will see later I decided to put them both in as a single unit. This was scary but well worth it.





Then I started pulling the beast out.










And it's officially out.








Here is a site I wasn't sure I would ever see.





One of the surprises was the water cooled alternator. I have never heard of one of these before. Here is the port on the block that the alternator seals to.





This is the alternator.








Also a note of caution, the plastic parts are very brittle. I snapped the nipple off this turbo waste gate controller when removing the rubber hose. Luckily the new one was only $27.




Here is the old, and new engines side by side as I transfer all of the stuff.




Something worth noting, although these engines are identical but because they are from different cars there are some significant differences that need to be addressed. For example, the oil pans, and subsequently the oil pump and pick up are completely different and need to be swapped over. Also the windage tray is different. A related problem was that since the pans are different, the oil level sensor on an SL600 is located in the rear on the driver’s side and the sensor in the S600 is in the front on the passenger side. This required me to splice in the sensor to the SL600 wiring harness and route it to the opposite side of the block. Also the large intercooler hard lines located under each coil pack that are running front to back are slightly different and will require swapping out. One last but significant thing is the main wiring harness that goes from the engine to the vehicle is slightly different. On the SL600, it has one large white connector and on the S600 it has a small white connector. This was easily fixed by pushing the pins out of each and reinserting them into the smaller connector.





During the reinstall I learned another very valuable lesson. When approximately a ton of metal is hanging from an aluminum lifting eye, try not to have the load bounce. This is how the lifting eye is supposed to look.





And this is how it looks after you close the hoist hydraulic valve too quickly with the load coming down. Luckily it was only about 2 inches off the floor when it went "SNAP".




As you can see I ended up drilling a new hole in the lifting flange and used a high strength nylon strap which worked great. Here is the entire load ready to go back in.





However before I go into that I should tell you about the specific problems with re-attaching the transmission. First off the torque converter is a specific fit. What I mean by that is for example compared to a regular Chevy transmission where you can bolt up the trans bell housing regardless of if the torque converter bolt holes are aligned, with this transmission the bolt holes must be aligned with the flex plate or it will not mate up. Again, ask me how I know this.

Here is the engine and trans tilted and starting to be installed.




Notice how extremely tight the clearances are.








For those that think I should have removed the radiator to gain more clearance, that was a thought but for those that have done that job, of which I am one, it is NOT as easy as it seems. As it turns out I didn't need to anyway.

The Eagle has landed.





Now I'm in the process of hooking everything back up and getting it ready to light back off. Wish me luck.

jnash

impressive work, good luck.
I didn't think you were ever to gap iridium plugs? well i guess you found out the hard way??

tusabes

Great write up on the install

So this whole engine problem was caused by gapping a spark plug ?

Quadcammer

wow dude nice work. i'm amazed you were able to angle that thing in.

did you ever consider just dropping the front subframe with motor and trans?

that snapped lifting tab would have scared the **** outta me.

shardul

iTrader: (1)

nice work for 2000 the M275 is a steal!!!

04S600AMG

I have done a fair amount of research online and have come away with conflicting stories and opinions on the gapping of the plugs. Some say the plugs come pre-gapped while others say don't trust them. Some say the gap should be .028 to .037 while the NGK website says these plugs for our cars should be .044. I found several of the gaps right out of the box varried from one another by as much as .008.

04S600AMG

Even the NGK website says that you should check and adjust the gap even on iridium plugs. However they do caution that you should not use a "coin" style gapping tool as these tend to break the precious metal tip inside the plug.

04S600AMG

Trust me I had many late nights just contemplating what I should do. Removing the sub frame looked to be more of a nightmare because of all the peripheral stuff attached. I am so glad that I decided to install the engine and trans as a unit. I can't even imagine how many times I would have been in a fit of rage under that car trying to wrestle that trans into position. Also the two top bell housing bolts were a serious PITA to get out while the trans was in the car. I think getting them back in would have proven to be very difficult. In the end I had to adjust the hoist tilt mechanism chain to get an angle that had a chance of working.

You are right about the tab breaking. I nearly had a heart attack. I think that if I had used a strap on the eye in the first place instead of trying to bolt the metal lifting piece directly to it, the side loads would not have been as severe and the tab probably wouldn't have snapped. Lesson learned.

shardul

iTrader: (1)

how many hours did it take you to do this.

04S600AMG

This has taken me around 25 hrs so far spread over around 3 weekends. However I was taking my time making sure everything was cleaned and that I meticulously documented every last nut bolt and fastener. If I had to I probably could cut that time in half especially if I had all the parts like gaskets and O-rings ahead of time. The cost so far is around $2000 for the replacement engine, $80 for the engine oil and filter, $235 for various gaskets and seals, $275 for spark plugs, $85 for ABC and power steering oil, $50 for trans fluid, $180 for A/C recharge service, $27 for new turbo waste gate controller cover, and $24 for new exhaust pipe to manifold bolts. So around $2,876 if the math in my head is right.

MRAMG1

Very nicely done my friend. A V-12 for 2K is a fantaastic price, as I have been looking for a bare block for years and can get one for under 5K.

Good luck.

corkshoppe

you are 1 sick awsome dude. wow!

04S600AMG

Engine replacement update. Ok, everything is in, hooked up, fluids topped off, and she runs like a rocket!!! I really didn't have any major issues at all. One of the O2 sensors crapped out but that was expected since it was from the bank of cylinders that had the bad cylinder on the old engine. A couple of days after I got her running I got an unrelated SRS warning message which I have to get checked out but other than that and a few minor problems that were there before I started replacing the engine I am LOVING my car again. It's amazing how much power I am getting from this low mileage replacement engine and the Eurocharge tuning. It easily feels like 600 hp at the rear wheels. If anybody is in need of some new coils I do have a brand new, never even installed set of coils to sell if anybody is interested. I bought them back when I thought it was a coil and not a burned cylinder. So I am willing to make somebody a good deal. Let me know.

haoz129

Congrats, really impressive,

richvegas

i've done all the work on my 65 myself, but this is awesome! Great job man, hope i never have to try it...

Welwynnick

How did I miss this thread? Fantastic work. I'm amazed you got the engine & tranny back in together.

I've been doing something not too dissimilar this year (turbos, motor mounts, diverter valves and ABC pipes) and decided to do it by dropping the subframe instead. Not difficult in itself, but now I finished I kind of wished I'd simply removed the engine, too.

Interesting about the differences between the S and the CL. I knew the SL and Maybach were different, but the CL...

Great stuff, Nick

Welwynnick

I wanted to ask you about that. You obviously have a lot of experience and capability working on cars, so when you say something is difficult, then it really must be.

What is it that makes the transmission difficult to refit on its own?

Was it the access to the top of the bellhousing, and aligning the torque converter, or was it other things as well?

Cheers, Nick