The Mercedes-Benz M113 engine will be remembered as one of the most legendary performance engines ever. This magnificent V8 creation from Mercedes was named the “Best Performance Engine” of 2003 and as time has shown, it was well deserved. If you’re in the market for a Mercedes with the M113 engine, you’re in for a treat. This article covers all the common M113 engine problems.
The M113 came in various displacements ranging from 4.3L to 5.4L and a power output ranging anywhere from 279 to 641 horsepower. It featured an aluminium engine block with an aluminium head and 3 valves per cylinder. To make it almost literally bulletproof, Mercedes equipped the M113 with fracture-split forged steel con rods, one piece cast camshaft, a magnesium intake manifold, iron coated piston skirts and a sequential fuel injection system.
Common Mercedes-Benz M113 Engine Problems
It’s important to point out that some problems below tend to be user inflicted and a consequence of poor maintenance. If there was ever an engine where we could claim that it is almost fault-free, the M113 would be it. Apart from some smaller issues, this is as reliable as you can expect a V8 to be.
M113 K – Kompressor intercooler pump failure
As is evident from the title, this issue only affects the supercharged version of the M113 engine, the Kompressor V8. Found in cars like SL 55 AMG, S 55 AMG and other 55 AMG of that time, the M113 K engine features intercoolers that cool off the pressurized air of the supercharger.
When the intercooler pump fails, the increased intake air temperature (IAT) will shut down the supercharger, leaving the car feeling powerless. It does this to prevent further serious engine damage. According to the owners in this owner’s forum thread, the temperature at which this happens varies greatly.
Replacing the intercooler pump is not expensive (~ $200) and it’s a fairly simple procedure. The OEM intercooler pump is always replaced with the more reliable, updated Bosch 010 intercooler pump. If you’re planning on modifying the M113 K, there are also plenty of after market options that will better cool an engine with increased boost and power.
Spark plug failures
This is one of those issues that is mostly brought upon by careless owners. Erratic engine operation and misfiring of the M113 engine is usually a consequence of old spark plugs. Owners tend to put off replacing the spark plugs because there’s 16 of them, 2 per cylinder.
They should be replaced every 50,000 miles (80,000 km) and yes, it’s not the cheapest thing, but it needs to be done. Old spark plugs also tend to get stuck in the engine, so make sure you remove them carefully.
Rear main seal deterioration
These cars are getting on in age, there’s no denying it. With time, all the rubber gaskets and plastic components tend to deteriorate and potentially leak oil. As some of you might know, completely resealing a V8 engine is not exactly cheap (I spent $500 to replace all the gaskets on my V6 OM642 Mercedes engine).
The M113 in all of its variants is known to leak oil at the rear main seal. This rubber seal gasket seals the crankshaft at the transmission joint. An experienced mechanic will have no problem identifying this leak, and we recommend you get it taken care of before it gets bad.
It’s not the cheapest of repairs, but it only needs to be done once every 15 years, so it’s definitely not a big deal. If you’re buying a Mercedes with the M113 engine, we recommend checking the condition of this seal before you purchase the car. It’s a good sign that the car was well-serviced if the seal has already been replaced, and if not, you have good leverage to lower the price of the car.
Read this owner’s forum thread to learn more.
Engine breather cover oil leak
Another common origin of oil leaks on this engine is at the engine breather covers that are located on both sides of the engine, right under the engine cover. These oil leaks tend to occur even at low mileage due to deterioration of the sealant. These covers don’t use rubber or metal gaskets, the correct sealant must be applied on a completely clean surface with a syringe.
Cleaning and resealing these covers is fairly cheap at $50, and it can be easily done on your own. We recommend buying the repair kit and following the meticulous instructions from Mercedessource.com.
The lack of oil pressure sensor
The M113 engine in all its variants comes without an oil pressure sensor. Not having the ability to detect low oil pressure values can lead to complete engine failure, which is exactly what happened to this owner. Installing an aftermarket oil pressure sensor is a wise decision to prevent such rare occurrences.
Valve cover gasket leaks and oil pan leaks
Staying on the topic of oil leaks, when buying a car with the M113 engine, make sure you take off the plastic engine cover and inspect the area around the valve covers. Seeing oil seepage around this area is not uncommon, especially on the supercharged M113 K 55 AMG engine. Replacing these covers is fairly inexpensive and simple.
More complicated to fix are the oil pan leaks, which are also known to occur. To access the oil pan gasket, the entire front subframe needs to be dropped before getting the appropriate access. This makes the entire process a lot more complicated and time-consuming.
M113 K Supercharger problems
The supercharger or the “Kompressor” as the Germans like to call it is magnificent and reliable. There are 2 things we want to point out.
- Keep things cool If you live in an area with a hotter climate, and you enjoy pushing your car to the edge, make sure you invest into an aftermarket performance intercooler. This relatively affordable mod will do wonders to keep the supercharger running cool and extend its lifespan. You should also make sure that your intercooler pump runs with no hiccups. Upgrade to the Bosch 010 updated pump to stay safe.
- Replace the Supercharger pulley bearing A worn out supercharger pulley bearing on the M113 K engine turns your smooth V8 into a grinding, loud tractor sounding machine. The part at fault is usually a worn out Kompressor pulley bearing. Mercedes doesn’t just sell the pulley bearing, they only sell the complete pulley clutch carrier assembly for approx. $1000. Luckily for you, there’s aftermarket bearings that costs much, much less – $50 (Nachi part number 45BG07S5AIG-2DL or 45BG07S5DL). Replacing this bearing will ensure a smooth, silent engine operation.
Crankshaft position sensor
A failed crankshaft position sensor can leave you stranded by the side of the road. The M113 engine is known to throw the P0335 diagnostic trouble code, which indicates a malfunctioning crankshaft sensor. Replace the sensor at the first sign of trouble.
Engine motor mounts
Keeping all these M113 horses buckled up poses some serious stress on the engine mounts. Excess engine vibration, lurching at startup and noticeable differences in drive quality can all indicate problems with worn out engine motor mounts. Keep these symptoms in mind when buying a Mercedes with this engine.
Which Model Year M113 Engines are Most Reliable?
Based on our experience and the opinion of many owners online, the best thing you can do is choose a 2006 model year or later. These engines already came with an upgraded intercooler pump and several other improvements that the earlier model years of the M113 lack.
Which Mercedes-Benz Cars Have the M113 Engine?
The M113 was used in various Mercedes-Benz vehicles ranging from 1997 to 2011. During this time, the engine received numerous updates, including a supercharger kit in 2002. Supercharged M113 K wore the 55 AMG V8 Kompressor badge.
Here are all the versions and the cars carrying a particular version of the M113.
|Engine version||Basic specifications||Cars with this engine|
|M113 43||4.3 L |
|1997-2000 C-Class 43 AMG |
1997-2002 E-Class 430
1998-2003 CLK-Class 430
1999-2001 ML-Class 430
1999-2006 S-Class 430
|M113 50||5.0 L |
|1998-2008 G-Class 500 |
1999-2006 S-Class 500
1999-2006 SL-Class 500
2000-2006 CL-Class 500
2001-2008 ML-Class 500
2002-2006 CLK-Class 500
2002-2006 E-Class 500
2004-2006 CLS-Class 500
2006-2007 R-Class 500
|M113 55||5.4 L |
342 – 362 horsepower
|1997-2000 C-Class 55 AMG |
1998-2001 SL-Class 55 AMG
1998-2002 E 55-Class AMG
2000-2002 S 55-Class AMG
2000-2003 ML 55-Class AMG
2000-2003 CLK 55-Class AMG
2002-2006 CLK 55-Class AMG
2001-2002 CL 55-Class AMG
1999-2003 G 55-Class AMG
2004-2010 SLK-Class 55 AMG
2006-2008 SLK-Class 55 AMG Black Series (400 hp)
2005-2007 C-Class 55 AMG
|M113 K||Supercharged (Kompressor) |
Twin intercooled 5.4 L
469 – 574 horsepower
|2003-2006 CL-Class 55 AMG |
2002-2006 S-Class 55 AMG
2002-2008 SL-Class 55 AMG
2003-2006 E-Class 55 AMG
2004-2006 CLK-Class DTM AMG
2004-2011 G-Class 55 AMG 2004-2006 CLS-Class 55 AMG
Based on this table, you should have no issues figuring which engine you have or is in the car you’re looking to buy.
We really went deep into all the possible engine problems of the M113. The truth is, most of the issues above are easily resolved with regular maintenance. It’s easy to see why this is one of the most popular Mercedes petrol engines.
Artisanmotor revealed how good can these engines look like at 273,000 miles! Do we need to add anything else?
Is the M113 Mercedes engine reliable?
Based on our experience and research, the M113 engine is one of the most reliable high performance engines ever produced. With regular maintenance and care, these engines have no problems that would prevent them from reaching 300,000 miles (ca. 482,803 km) or more. The majority of common M113 engine problems can be prevented with regular maintenance and care.
What is the weight of the Mercedes M113 engine?
According to Mercedes, the weight of the M113 43 engine, which is the 4.3L version of the M113, is 206 kilograms or 454 lbs. This is the only available official weight figure, but we presume other, bigger versions of the engine can be a bit heavier.