The Seven Most Common BMW N52 Engine Problems. BMW’s N52 engine is among its most effective, and many produced inline-6 engines. The N52 was predominately found in the E90 325i, 330i and 328i, and the E60 525i and 528i designs, as well as different others such as the 128i, X1, and Z4 among others. The N52 was produced from 2004 up till 2015 when it was changed by the turbocharged N20 engine. It is the follower to the M54 which was used in various E36, E39 and E46 models.
Offered the long production history, BMW had the ability to best many elements of the engine over the production life time. The engine even won leading 10 best engines in both 2006 and 2007. However, the N52 still has its reasonable share of common reliability problems. We’re going to attend to the 7 most frequent engine issues the N52 experiences.
Due to the engine design, the BMW N52has actually shown more dependable than it’s bigger brother, the N54. These are two common N54 problems that drivers of the N52 won’t have to fret about due to the fact that the N52 does not have an HPFP or direct injection. We likewise composed an N54 engine problems guide you can read to compare the two!
BMW N52 (328i, 528i) Engine Problems
- VANOS failure
- Hydraulic valve adjusters (lifters).
- Water pump and failure.
- Thermostat failure.
- Oil filter housing gasket/leak.
- Rough idling and sluggish start-up.
- Valve cover leak.
These are the most common engine problems, beyond these problems the car is very trustworthy and problem complimentary. I will point out one other common, non-engine associated issue is the window regulators. This results in the affected window not being to roll up or down. Replacement expense is approx. $500 at a shop for the part plus labor.
1. VANOS Failure.
The N52 engine utilizes BMW’s VANOS system, which is a variable valve timing system. The VANOS solenoids are accountable for controlling just how much oil flows to the webcam gears, which in turn controls the opening and closing of the valves. Comprehending VANOS is rather complicated, although you can read our full guide about it here.
Stopping working VANOS solenoids will lead to a loss of power, poor idling, bad fuel economy, trouble beginning, and the occasional limp mode.
These solenoids typically fail every 70,000 miles or two. We recommend changing them at this interval as they are likely having an unfavorable affect on performance, although you may not understand it.
Engine Codes for VANOS Failure.
- P1520: Camshaft position actuator, exhaust.
- P1523: Camshaft position actuator is jammed, exhaust.
- P1397: Camshaft position sensor B.
- 2A82: Vanos consumption solenoid.
- 2A87: Vanos tire solenoid.
The 2A82 and 2A87 codes are for the consumption and exhaust solenoids. The solenoids are precisely the exact same, so you simply require to acquire 2 of part # 11-36-7-585-425 to replace these.
If you buy the solenoids from the links above you can utilize the code “BMWTUNING” to get 5% off.
VANOS Repair Work Expenses: $178 for the solenoids, about $200 in labor if not DIY’ed.
DIY Trouble: Intermediate.
DIY Guide: https://bmwtuning.co/vanos-solenoid-replacement/.
2. Hydraulic Valve Adjusters (Lifters) Ticking Problems.
Typically on greater mileage cars (normally 50,000+), drivers will experience an annoying ticking or rattling sound coming from the engine. It is most common during cold weather or on short trips. The ticking sound is brought on by the hydraulic valve adjusters, likewise referred to as lifters, not getting sufficient oil to function properly.The lifter ticking sound isn’t damaging to performance or hazardous to the engine, but rather it is incredibly annoying and more of a problem.
The lifters do not get enough oil due to poor design in the lifters and the cylinder head. This is just common in 2008 and earlier models. The designs of the lifters and cylinder head was changed in December of 2008 which fixed this problem.
How to Repair Lifter Ticking Sounds.
The very first path, and totally free path, to take is to “bleed” the lifters. To do this, drive only the highway for 30-minutes at high RPM’s (> 4500rpms). The majority of the time bleeding the lifters is a short-lived fix that might work a few times in a row till a more irreversible service is required.
The long-term option is to replace the lifters and the cylinder head with the freshly designed post-2008 parts. I don’t think any pre-2009 N52’s have any warranty left, so you will be footed with a $2-3k bill to get this problem changed if it hasn’t already been taken care of.
I expect the third choice is to simply drive with the ticking sound and put up with it.
Repair work Expense: $3k+ at a store.
DIY Problem: Really challenging.
3. N52 Water Pump Failure.
BMW’s are notorious for water pump failure, and it is definitely extremely common on the N52. It’s also a regular problem on the N54 … I blew mine at 42k miles, our E60 blew one at 60k miles, and our E90 had actually a failed one at some time as well.
BMW’s use a electric water pump, instead of a standard water pump. The electric water pumps are made out of plastic, which gradually usually starts wearing away and cracking. The impellers and bearings are likewise common parts that fail within the water pump. Water pumps generally stop working around the 80k mile mark. We recommend getting a brand-new water pump that has a metal impeller, given that we see the impeller being a common cause of failure.
Symptoms of N52 Water Pump Failure.
- Engine overheating (even when simply idling).
- Dripping coolant.
- Steam coming from the radiator.
Water Pump Replacement Cost: ~$ 400 for the pump, $800 with labor included.
BMW N52 Water Pump.
BMW N52 Thermostat.
DIY Difficulty: Intermediate to Difficult.
DIY Guide: https://www.e90post.com/forums/showthread.php?t=565770.
4. Thermostat Failure.
Thermostat failure can in some cases be mistaken as water pump failure and vice versa. Because the water pump and thermostat work in tandem to manage engine temperatures, this is.
Automotive thermostats start in a “closed” position, which assists the car reach regular running temperatures much faster. The thermostat then slowly “opens” as temperatures rise. When it opens, it forces the hot engine coolant into the radiator to be cooled down, and the water pump pushes the chillier coolant from the radiator to the engine.
Thermostats can fail in either of two positions: opened or closed. Stopping working closed means the car is not biking cold coolant into the engine, resulting in extremely fast overheating, and potential major engine damage from running at such high temps. Continuing to run a car with a closed thermostat can lead to head gasket failure, radiator breaking, and cracking/failure of other cooling components.
N52 thermostats are built to fail in the open position. Stopping working in the open position is the most desirable option, as it is the least harmful to the engine. With that being said, it still isn’t good for the car.
N52 Thermostat Failure Symptoms.
- Engine is overheating quickly, gauge reads at a loss rapidly (stuck in closed position).
- Engine takes a truly long period of time (20 mins or so) to reach regular running temperatures (stuck in open position).
- Irregular temperature level changes.
- Coolant dripping near the thermostat.
The thermostat typically fails in addition to the water pump. With the thermostat being relative cheap, we suggest replacing it while replacing the water pump as it will conserve some costs on labor compared to changing them individually.
Thermostat Replacement Expenses: about $70 for the part, and $150-200 in labor.
BMW N52 Thermostat.
DIY Trouble: Intermediate.
DIY Guide: https://www.e90post.com/forums/showthread.php?t=1093271.
5. Oil Filter Housing Leak.
Comparable to the valve cover gasket degrading with time, this likewise often takes place on the oil filter housing gasket. The gasket seals the oil filter housing to the engine block/cylinder head, and is the most common oil leak discovered in N52 and all N5x engines, in addition to the one noted above.
All oil leaks are serious, but the oil filter housing leak is the most major as it can damage your whole engine if neglected. If your leak ends up being big enough, oil will seep all the way down to the serpentine belt, and cover the serpentine belt with oil. As soon as this takes place, it is only unavoidable for the belt to slip off. When it slips off, it goes backwards and gets captured by the timing cover, which chews it up, leading to pieces of the serpentine belt going through the front crank seal and into the engine. This can kill your engine, or best case lead to a few thousand dollars of repair work.
N52 Oil Filter Houston Drip Symptoms:.
- Conditions similar to the valve cover gasket leak.
- Oil dripping underneath the vehicle.
- Smell of scorched oil in the engine bay.
- Leaking oil on or around the intake manifold.
- Oil spots around the front side of the engine.
Oil Filter Housing Replacement: about $30 for the gasket, $419 for the housing and gasket, and 1-2 hours of labor, probably $150-200 all in.
BMW N52 Oil Filter Housing – Consists of housing, gaskets, cap, and filter.
BMW N52 Oil Filter Housing Gasket – Gasket just.
DIY Difficulty: Intermediate.
DIY Guide: https://www.e90post.com/forums/showthread.php?t=632565.
6. N52 Rough Idling or Misfires.
We have actually heard a lot of people on the online forums complaining of rough idling and periodic misfires from the engine. Other common symptoms will be loss of power, sluggish starts, and bad gas mileage.
While these symptoms are all comparable to VANOS solenoid failure, they will not toss an engine code, and the VANOS solenoid will. If you aren’t getting an engine code you likely need to change your spark plugs and ignition coils. On N52 engines, these generally require to be replaced every 30,000-60,000 miles.
Bad Spark Plugs and Ignition Coils Symptoms.
- Poor idling, rough idling.
- Bad gas mileage.
- Sluggish starting, or issue starting in cold weather.
- Loss of power or sluggish performance.
N52 OEM Spark Plugs.
N52 OEM Ignition Coils.
DIY Trouble: Easy.
DIY Guide: https://www.e90post.com/forums/showthread.php?t=174217.
7. Valve Cover Gasket Leak.
Like the N54, the N52 engine is plagued by the very same common valve cover leak. The oil leak can be caused by 2 things: either the valve cover gasket degrading or from the valve cover itself splitting. Since the valve cover is made from plastic, it warps in time from the engine heat and can break. The result in both is oil dripping into your engine bay and also a build up of oil in the engine.
, if your valve cover fractures you will require to replace the gasket and the cover.. The very best case scenario is just needing to change the gasket, which is a lot cheaper.
Symptoms of N52 Valve Cover Leak.
- Spark plugs covered in oil (usually on the threads of the plug).
- Ignition coils covered in oil.
- Low engine oil light beginning.
- Oil in the crevices of the engine block, or signs of oil on the head.
- Smell of burning oil from the engine, possible engine smoking if its dripping a lot.
Leaking valve covers and gaskets are slightly more difficult to find compared to other problems because it will not result in any engine codes. You could get a low oil service light, however this likely will not occur unless you have a severe leak. The most convenient way to diagnose this problem is to get rid of the valve cover and see if you see a develop of oil underneath. Also, remove your spark plugs and ignition coils and see if they are covered with oil and if there is standing oil at the bottom of the valves.
N52 Valve Cover Replacement: approx. $40 for the gasket, about $450 for the cover and gasket. This is probably 6-8 hours of labor from a mechanic, so it can get expensive.
BMW N52 Valve Cover – Includes valve cover, gasket, and bolts.
BMW N52 Valve Cover Gasket – Gaskets just.
DIY Trouble: Intermediate to challenging.
DIY Guide: https://blog.fcpeuro.com/n51-n52n-valve-cover-gasket-replacement.