M137.9 V-12 Reliability - PeachParts Mercedes-Benz Forum

jgl1 · #1 04-17-2006, 01:23 PM

Any reason to avoid the V-12 found in the 2002-2006 CL 600, other than poor fuel economy? A high depreciation rate means used CL 600s presently can be had for only slightly more than the V-8 version. Would a CL 55 be a better alternative?

DR.DIESEL · #2 04-17-2006, 10:29 PM

Do your self a favor and avoid any 600 with the M137 V-12 engine.
2000-2002 CL and S's. They are notorious for out of round cylinder walls
and oil fouling. I have replaced at least 10 of those engine's myself in the
last couple years for local clients. 2 of them, I had to replace the replacment
engine. A CL or S55 is a much better choice. Even the 500 is fine.
The 55 only gives up 18 hp to the V-12.
Extended warranty contract companies won't issue policies on v-12's.
We wholesale them out if they have no original warrany coverage when they come in on trade. That is why they are so damn cheap.
The only client I have that has had no issues with his 01 S600, drives the
snot out of it. 110k so far. The car has been great. All the low mile garage
queens with 20k die a expensive death.
(example : the excessive blow-by oil fouls out the 8 downstream o2 sensors
at $1600 total. The cats if damaged by oil cost $8,000 to replace all 6.
The engine can run over $34,000. parts only!....and on and on.)
The 2003's are a diffenent story. They have been virtually flawless.

On the lighter side, when running well they can get 25mpg on the highway.
Not bad for a v-12.

DR.D

trueog · #3 04-17-2006, 10:35 PM

Hey Doc diesel, do you own a shop? or work for a dealer? I like reading you're posts, very informative. Just wondering how you find all this out?>
thanks

Quote:

Originally Posted by DR.DIESEL

Do your self a favor and avoid any 600 with the M137 V-12 engine.
2000-2002 CL and S's. They are notorious for out of round cylinder walls
and oil fouling. I have replaced at least 10 of those engine's myself in the
last couple years for local clients. 2 of them, I had to replace the replacment
engine. A CL or S55 is a much better choice. Even the 500 is fine.
The 55 only gives up 18 hp to the V-12.
Extended warranty contract companies won't issue policies on v-12's.
We wholesale them out if they have no original warrany coverage when they come in on trade. That is why they are so damn cheap.
The only client I have that has had no issues with his 01 S600, drives the
snot out of it. 110k so far. The car has been great. All the low mile garage
queens with 20k die a expensive death.
(example : the excessive blow-by oil fouls out the 8 downstream o2 sensors
at $1600 total. The cats if damaged by oil cost $8,000 to replace all 6.
The engine can run over $34,000. parts only!....and on and on.)
The 2003's are a diffenent story. They have been virtually flawless.

On the lighter side, when running well they can get 25mpg on the highway.
Not bad for a v-12.

DR.D

DR.DIESEL · #4 04-18-2006, 10:18 PM

They keep me in a dark room all day and feed me trouble cars that other
dealers can't fix. If I behave, they won't zap me!

I work at the dealer level for now.
I am honing my skills to work for MB telling owners there is nothing wrong
with their cars and all is normal.
ZZZZZAAAAAPPPPPPPP!!!!!!!

Ah crap......They got me......
DR.D

davestlouis · #5 04-18-2006, 10:26 PM

We had a CL600 at my shop recently, it had some sort of oil leak, the oil got into a transmission controller unit and fried it...I want say it cost $6500 to change the controller out, largely due to the unbelievable labor involoved in getting to it. At $112/hr it doesn't take long to run up a big bill.