M156 vs M104

Side-by-side reliability comparison

Higher reliability score
M104 BEST 85/100
+25 points over M156
0 / 100
CAUTION M156 Mercedes-Benz
0 / 100
BEST M104 Mercedes-Benz

Specifications

M156
M104
Brand
Mercedes-Benz
Mercedes-Benz
Verdict
CAUTION
BEST
Reliability
60
85
Years
2006--2015
1990--1997
Displacement
6208 cc
3199 cc
Layout
V8
I6
Type
Petrol Na
Petrol Na
Power
457--514 hp
193--231 hp
Known Issues
2
1
Total Risk Cost
€2,500--€7,500
€500--€2,000

Character

M156

"C63/E63/S63 W204/W212/W221. Head bolt failure on early units (2007-2008). Intake manifold swirl flap. Cam adjuster bolts. Incredible NA V8 sound. Later production much improved."

M104

"W124/R129/W140 inline-6. One of Mercedes' most reliable engines. Bulletproof bottom end. Wiring harness biodegrades (uses soy-based insulation). Head gasket solid. 400k+ km possible."

Issues Comparison

M156 2

◆ CRITICAL
Head bolt failure (2007-2008) €2,000--€6,000 40,000 km--100,000 km
▲ HIGH
Intake manifold swirl flap €500--€1,500 60,000 km--120,000 km

M104 1

▲ HIGH
Wiring harness biodegradation €500--€2,000 100,000 km--200,000 km

Models

M156 3

CLK W209 2006--2009 E-Class W211 2006--2009 C-Class W204 2008--2014

M104 0

No models listed.

Full M156 Report Full M104 Report