S65 High Idle, Alternator replacement, All related
12-21-2023, 02:20 AM
#1
Senior Member
Thread Starter
S65 High Idle, Alternator replacement, All related
I have had quite a bit of fact-finding/ issues resolved to report on.
For those who have been following this at home >>"S65 High Idle, Alternator replacement"<<, you should read/see this first;
The summary is I have a 4-poster lift and just about all the special tools to work in the confinement areas of the V12s and have the practical experience of having removed and, installed, rebuilt a V12 engine three times in a W220 chassis, so based on that background I'm not intimidated by any MB V12 work.
However, the W222 chassis is different and requires a different approach.
By disconnecting the car battery, removing the radiator fan (together with its housing), undoing the surrounding hoses and electrical connections, removing the air pump from its mounting bracket (leaving the bracket on the engine), removing the under-front engine bay cover, and painstaking use of a variety amount of angled wrenches and socket (from above) I managed to the get the alternator out and re-install without the removal of the radiator (I did need to drain the coolant and remove some of its hoses) Rough time estimate to do this for the first time around was about 16 hours.
So, after the replacement alternator was installed, I anticipated that all my problems would be solved and happy S65 motoring would continue from here on.
No, it was not. The car would start, but the motor would only run in limp mode, so after running Xentry and not getting any engine codes, I asked my friend Peter (2 Dutch guys are better than one!)(better known here as Benz Ninja) to take a look. We decided to replace and recode the front SAM unit. (It is the router/SAM) that runs all the ignition-related electric supplies to the engine.
You must realize the car had been running fine until the alternator failed, and replacing it should have solved all the issues. With the limp mode problem still there, the thought came to mind that when the alternator went bad, it may have spiked the ECU, and it needed to be replaced. So, in an attempt to recode the ECU, it was found that Xentry could not read it. Perhaps the PO of the car had it tuned at one point in time. Hence, the only option left was to re-flash the ECU and install the original MB software back on it, and indeed, after it got flashed, Xentry could read the error codes. It revealed that the # 1-6 cylinder bank fuse was bad. After it was replaced, the car was no longer running in limp mode.
We have further found that the cats have been hollowed out (we assume when they did the tune). CEL now stays on until I get the cats taken care of. The oxygen bank two sensor 2 needs to be cleaned/replaced, and the boost system controller was also capped. Removed the cap, cleared the line, and codes for it.
So the car is running fine now and idles as it should at 633RPM. I am looking into the best way to resolve the cat's issue so I can have the EC light off again.
It has been quite a little ordeal to get it sorted out, but the best way to keep these cars is to keep them stock.
Happy motoring to all, and happy holidays.
HK
For those who have been following this at home >>"S65 High Idle, Alternator replacement"<<, you should read/see this first;
- >Read> Post #10 > https://mbworld.org/forums/s63-amg-s...high-idle.html
- >Read> Post #11 John, your offer for $10k has been declined (the issues have been resolved)
- >See> Post #1 > https://mbworld.org/forums/s63-amg-s...5-s65-amg.html
The summary is I have a 4-poster lift and just about all the special tools to work in the confinement areas of the V12s and have the practical experience of having removed and, installed, rebuilt a V12 engine three times in a W220 chassis, so based on that background I'm not intimidated by any MB V12 work.
However, the W222 chassis is different and requires a different approach.
By disconnecting the car battery, removing the radiator fan (together with its housing), undoing the surrounding hoses and electrical connections, removing the air pump from its mounting bracket (leaving the bracket on the engine), removing the under-front engine bay cover, and painstaking use of a variety amount of angled wrenches and socket (from above) I managed to the get the alternator out and re-install without the removal of the radiator (I did need to drain the coolant and remove some of its hoses) Rough time estimate to do this for the first time around was about 16 hours.
So, after the replacement alternator was installed, I anticipated that all my problems would be solved and happy S65 motoring would continue from here on.
No, it was not. The car would start, but the motor would only run in limp mode, so after running Xentry and not getting any engine codes, I asked my friend Peter (2 Dutch guys are better than one!)(better known here as Benz Ninja) to take a look. We decided to replace and recode the front SAM unit. (It is the router/SAM) that runs all the ignition-related electric supplies to the engine.
You must realize the car had been running fine until the alternator failed, and replacing it should have solved all the issues. With the limp mode problem still there, the thought came to mind that when the alternator went bad, it may have spiked the ECU, and it needed to be replaced. So, in an attempt to recode the ECU, it was found that Xentry could not read it. Perhaps the PO of the car had it tuned at one point in time. Hence, the only option left was to re-flash the ECU and install the original MB software back on it, and indeed, after it got flashed, Xentry could read the error codes. It revealed that the # 1-6 cylinder bank fuse was bad. After it was replaced, the car was no longer running in limp mode.
We have further found that the cats have been hollowed out (we assume when they did the tune). CEL now stays on until I get the cats taken care of. The oxygen bank two sensor 2 needs to be cleaned/replaced, and the boost system controller was also capped. Removed the cap, cleared the line, and codes for it.
So the car is running fine now and idles as it should at 633RPM. I am looking into the best way to resolve the cat's issue so I can have the EC light off again.
It has been quite a little ordeal to get it sorted out, but the best way to keep these cars is to keep them stock.
Happy motoring to all, and happy holidays.
HK
Last edited by Hendrik Koster; 12-22-2023 at 09:39 AM.
The following 2 users liked this post by Hendrik Koster:
carlosinseattle (12-21-2023),
TooManyIDs (12-25-2023)
12-24-2023, 12:00 PM
#3
MBWorld Fanatic!
Hendrick.....
Congrats at navigating the minefield that is ‘following after Elroy’ where ‘enhancements’ have been done in a half-assed fashion.
A temporary fix for your cat codes.... purchase a pair of ‘O2 sensor extenders’ that thread into rear O2 sensor holes and place the rear O2 sensors an inch or so from exhaust flow which will trick the rear sensor into not seeing the same as front sensor. It will still stink out the tailpipes until you give her exhaust Kittas but at least you’re not seeing that warning every time you drive.
Merry Christmas!
Congrats at navigating the minefield that is ‘following after Elroy’ where ‘enhancements’ have been done in a half-assed fashion.
A temporary fix for your cat codes.... purchase a pair of ‘O2 sensor extenders’ that thread into rear O2 sensor holes and place the rear O2 sensors an inch or so from exhaust flow which will trick the rear sensor into not seeing the same as front sensor. It will still stink out the tailpipes until you give her exhaust Kittas but at least you’re not seeing that warning every time you drive.
Merry Christmas!
