This 2009 Mercedes-Benz SL, AMG, is undergoing an extensive repair due to damaged head bolts. This is a fairly common issue with the Mercedes-Benz "63" M156 big block 6.2 liter engine (See below for list of vehicles this engine is used in). Symptoms of the head bolt failure include engine misfiring and unexplained coolant loss. Most often a check engine warning light will show on your dash display, in this case, we offer a free "engine light" check service to begin to identify if this is the issue. If these symptoms are ignored, the issue will quickly begin to cause serious damage to other engine components.
The repair procedure is to replace the broken head bolts with an upgraded, heavy duty head bolt. This process requires removal of the cylinder heads and replacement of the cylinder head gaskets (as well as other necessary gaskets) as seen in the next few images below.
Shown above the camshaft covers, intake manifold and other necessary parts are removed exposing the access to the the the head bolts.
The image above shows the broken bolt, with the head of the bolt missing.
Shown above, the cylinder heads are removed from the engine.
Shown above, displays where the head of the bolt snapped. Notice the recessed "female" star-bit style of the head bolt.
Below shows the new upgraded head bolt in comparison to the old. Notice the new head is a "male" style of head bolt, providing more strength to the bolt for tightening to torque specifications.
With higher performance applications, some choose to swap head bolts to a hardened stud (Such as ARP fasteners). While this is a much stronger fastener and can stand up to much more abuse, it does make it the removal service of the bolts a bit more difficult to remove the cylinder heads -- if ever the situation arises to remove them again. For this customer's application, which is street driving, we chose the heavy duty upgrade.
Overall, for any higher mileage Mercedes AMG (See the vehicles listed below), whether it's normal driving or if you're planning for more aggressive driving, we recommend this service to be performed. For more information about the cylinder head bolts replacement, contact us at 941-922-3600 or click here: https://www.rennhaus.com/contactus
Vehicles the Mercedes AMG "63" M156 6.2 liter engine was used in:
2008 C63 AMG (Sedan and Wagon) (facelifted for the 2012 model year
2010 SLS AMG (M159)
In 2009, AMG developed the M159 engine, which is based on the M156 engine, to use in SLS AMG. The M159 produces 583 horsepower and 489 lb-ft of torque in the Mercedes-Benz SLS AMG GT, and 622 horsepower and 468 lb-ft in the SLS AMG Black Series. There are also other AMG nameplates no longer in production:
1988–1993 190E AMG 3.2
1988–1993 300E AMG 3.4E, AMG 3.4CE, AMG 3.4TE
1992 "The Hammer" AMG Widebody Coupe
1993–1994 E60 AMG
1994–1995 E36 AMG
1995, 1997 S70 AMG
1995, 1998–2001 SL73 AMG
1996–1998 SL60 AMG
1995–1997 C36 AMG
1997–2000 C43 AMG
1996–1998 E36 AMG
1996–1997 E50 AMG
1998–2002 E55 AMG
1998–2002 CLK-GTR AMG
2001–2004 SLK32 AMG
2002–2004 C32 AMG
2005–2006 C55 AMG
2005–2006 CLK DTM AMG
2007 R63 AMG