Automotive petrol engines. Differences to the N52 versions include a variable-length intake manifold ("DISA") with three stages instead of one, and a compression ratio lowered from 10.7:1 to 10.0:1. BMW N53B30 engine reliability, problems and repair. This DIY is going to be centered around handling the replacement of a valve cover gasket (and associated gaskets) on N51 and N52N engines. BMW developed a specific engine package that meets the SULEV standard - the BMW N51. Visually the N51 and N52 are identical. Also is the N52K better than the N51 and why? BMW is well known for its history of inline-six (straight-six) engines, a layout it continues to use to this day despite most other manufacturers switching to a V6 layout. I read the code and I was having constant misfires on Cylinder 5. Both have the same hp, n51 is sulev, it has the 3 stage intake and slightly lower compression. Both engines are very reliable. Even though it says "service", it's actually the equivalent to a CEL. Sure enough, the "Service Engine Soon" light came on. The N51 engine is a SULEV version of the N52 that was sold in parts of the United States that had SULEV legislation. This 3-liter engine represents N53 series which also includes N53B25.This motor was firstly introduced in 2007 and replaced 3-liter N52B30 engine.New unit has turned out to be modified version of N52 with improved cylinder block head equipped by direct injection. So basically my questions are: in comparison to other engines do the N51 and/or N52K standout as extremely bad engines? The 3 Series sedan packs driving enjoyment, creature comforts, high-tech features, and good fuel economy. The more common inline-four and V8 layouts are also produced by BMW, and at times the company has produced inline-three, V10 and V12 engines.. Prototype V16 engines have been … On the previous M56 SULEV and M54 engines in the E46 you could see a visual difference I have a 2009 128i w/ an N51 SULEV engine (if you're not sure, you can do a VIN check online) and my car was idling pretty rough. It is the first engine in the new N52 series ... engines and you should be aware if you have an N51 engine. Unlike early N52 engines, which used a magnesium valve cover and had an external crankcase vent valve, the updated version features a plastic valve cover with an integrated PCV valve. BMW N52 Bolt-On Performance Mods - Best N52 Engine Mods BMW N52B30 engine reliability, problems and repair. N51 is for states that require sulev. Get reliability information for the 2009 BMW 3 Series from Consumer Reports, which combines extensive survey data and expert technical knowledge. Lastly are these engines … My 2011 328 has the N51 and it has plenty of power. Each vehicle is different on repairs,,,not all the cars are the same,,,,yes the valve cover gasket could leak down the backside of the cylinder head down to the oil pan,,,,the only way to check and see if from look up from under the engine and look at the back of the cylinder head and follow the oil leak,,,,the oil pan also leaks the reason is age,miles and heat,,,,,because the … Toyota reliability isn’t expected but I’d like to not always have it in the shop either.