The N52 is one of BMW’s most well-known and effective inline-6 engines. The N52 engine was used mostly in the BMW E90 328i, 325i, and 330i models in addition to the E60 525i & 528i vehicles. Several other cars, including the X1, 128i, and Z4, to name a few, also utilised it. The production of the N52 lasted from 2004 until 2015, when it was finally replaced by the N20, which had a turbocharger. The M54, used in E36, E39, and E46, was superseded by this type.
Due to the engine’s long history of manufacturing, BMW improved a number of its parts while it was being built. Even prizes in the top 10 for best engines were presented to the motor in both 2006 and 2007. However, the N52 continues to have a number of common dependability concerns. We’re going to speak about the N52’s top 7 engine issues.
Due to the engine layout, the N52 has shown to be more trustworthy than its bigger sister, the N54. Because the N52 does not have an HPFP or a direct injection system, drivers of this vehicle will not have to be concerned about the two issues that are often associated with the N54. To compare the two, check our article on N54 engine problems!
Common BMW N52 (528i & 328i) Engine Problems
These are the most typical engine problems, although the vehicle is otherwise dependable and trouble-free. Window regulators, on the other hand, are a prevalent problem that has nothing to do with engines. Windows that are impacted won’t roll up or down, as a consequence. The item and labor add up to around R750 for a replacement.
Failure of the VANOS system
BMW’s VANOS valve timing technology is used in the N52 engine. The opening and shutting of the valves is ultimately controlled by the VANOS solenoids, which are responsible for regulating the amount of oil that goes to the cam gears. There is a lot to learn about VANOS, but we have included a comprehensive guide to help you out.
When the VANOS solenoids fail, the car loses power, idles poorly, consumes more gasoline, has difficulties starting, and even goes into limp mode sometimes.
Every 100,000 Km or so, the solenoids in these engines will fail. We suggest changing them at this time since they are likely affecting performance, even if you may not be aware of it.
BMW VANOS Engine Failure Codes
- P1520: Exhaust camshaft position sensor
- P1523: Exhaust valve actuator is stuck, camshaft position sensor
- P1397: Sensor B for the camshaft position
- 2A82: Intake solenoid for the Vanos
- 2A87: Exhaust solenoid for the Vanos
Intake & exhaust solenoids are identified by the 2A82 & 2A87 codes. Because the solenoids are identical, you just need to buy two of item #11-36-7-585-425.
Ticking Problems with Hydraulic Valve Adjusters (Lifters).
On vehicles with greater mileage (often 70,000+ KM), a ticking or rattling sound from the engine is frequently heard by the driver. Short journeys or chilly weather are when it happens most often. The ticking sound is a result of the hydraulic valve lifters, sometimes referred to as adjusters, not receiving enough oil to operate correctly. Noises coming from the lifters are neither dangerous nor detracting from the engine performance; they are just irritating and unwelcome.
Poor design of the lifters and cylinder head prevents the lifters from receiving adequate oil. Only models made in 2008 and before have this problem. This problem was resolved in December 2008 by changing the designs of the lifters and cylinder head.
Fixing Lifter Ticking Sounds
- “Bleeding” the lifters is the first, free course of action. Drive at high RPMs (>4500rpms) for 30 minutes on the highway alone to do this. Bleeding the lifters is often a short-term remedy that may be successful a few times before a more long-term treatment is required.
- The lifters and cylinder head need to be changed out with the freshly created post-2008 components as a long-term fix. You will have to pay a couple of thousands to get this problem fixed if it hasn’t already, as it’s unlikely any pre–2009 N52s have any remaining warranty.
- The third alternative, is to just accept the ticking sounds while driving.
Failure of N52 Water Pump
Water pump failure is notorious for BMWs, and it happens a lot on the N52. Additionally, it happens often on the N54.
Instead of a conventional water pump, BMWs employ an electric water pump. Because they are composed of plastic, electric water pumps usually tend to fracture and corrode over time. Another typical component of the water pump that fails is the impeller, followed by the bearings. Around 100 000 km is the typical failure point for water pumps. Due to the impeller’s tendency to fail, we advise purchasing a replacement water pump with a metal impeller.
The signs of a failing N52 water pump
- Even while the car is idle, the engine overheats.
- Coolant leaking steam emanating from the radiator
Water Pump Replacement Cost: +/- R5000
A broken / damaged thermostat
Thermostat failure and water pump failure might be mistaken for one other. This is due to the fact that the thermostat and water pump work together to keep the engine cool.
The “closed” setting of automotive thermostats helps the automobile attain normal operating temperatures more quickly. As the temperature rises, the thermostat progressively “opens.” When it’s open, the hot engine coolant is pushed into the radiator and the cooler coolant is pushed out by the water pump.
In either open or closed mode, thermostats may fail. Overheating may occur very quickly if the car’s coolant loop fails to shut, causing the engine to operate at dangerously high temperatures. The failure of a head gasket, a cracked radiator, and cracked/failed cooling components are all possible consequences of driving a vehicle with a closed thermostat.
Thermostats with the N52 model number are designed to malfunction when the door is left open. The engine will be less damaged if the failure occurs when the valves are open, which is the preferred scenario. In spite of this, it’s still bad for the vehicle.
Symptoms of N52 Thermostat Failure
- There is a problem with the car’s engine, and the temperature gauge is locked in the “closed” position.
- It takes roughly 20 minutes for the engine to get up to operating temperature.
- Inconsistent temperature changes.
- The thermostat is leaking coolant.
It’s normal for the thermostat and water pump to go out at the same time. As a result of the thermostat’s low cost, we suggest changing it at the same time as the water pump. Doing so will result in lower overall labor expenses as compared to the alternative of replacing each component individually.
Problem with the valve cover gasket
The N52 engine suffers from the same valve cover leaking as the N54. There are two potential causes of the oil leak: either a deteriorating valve cover gasket or a cracked valve cover. Over time, the valve cover warps due to the heat generated by the engine, causing it to break. Both scenarios lead to oil leakage into the engine compartment and oil buildup inside the engine.
You’ll need to replace both the valve cover and the gasket if it breaks. If just the gasket has to be replaced, the cost is much lower.
The signs of a leaky N52 valve cover
- Spark plugs that have been lubricated. Usually found on the plug’s threads.
- Oil slick on the ignition coils.
- It’s showing a low oil indicator light on.
- In the engine’s crevices or on the head, there may be traces of oil.
- A burning oil smell from the engine, and if it leaks a lot, the engine may start to smoke.
Regrettably, because leaky valve covers & gaskets won’t cause any engine codes, they are a little more difficult to see than other problems. A low oil service indicator may come on, although this is unlikely unless there is a significant leak. Taking off the valve cover and looking inside to see whether there is an accumulation of oil is the simplest approach to identify the issue. See whether there is any oil on the spark plugs or ignition coils, as well as in the valves themselves, by removing them.
Valve Cover Replacement Cost:
Approximately R300 for the gasket, R3500 for the gasket, and the cover. An auto technician will have to put in 6-8 hours of work, which may add up quickly.
Leak in oil filter housing
This also commonly occurs on the oil filter housing gasket, which may be compared to the deterioration that takes place over time on the valve cover gasket. There are a number of typical causes of oil leaks in N52 and N5x engines, including this gasket and the one stated before.
There are many types of oil leaks. The most dangerous is an oil filter housing leak, which may completely devastate your engine if left unattended. There are times when the serpentine belt is completely covered in oil because of a large leak. When this occurs, the belt will inevitably come undone. In this case, the serpentine belt becomes trapped in the timing cover’s teeth, resulting in parts of it passing through the engine’s front crank gasket and into the combustion chamber. Depending on the severity of the problem, this might result in a total loss of power, or a few thousand bucks in repair costs.
Symptoms of leaking valve cover gasket in the N52 oil filter housing
- The vehicle’s underside is covered with oil
- The engine bay smells like burning oil
- The intake manifold is dripping oil
- There are oil stains all over the front of the engine
Gaskets cost roughly R300 each, while the housing plus gasket set you back R3700 and 1-2 hours of effort.
Misfires or Rough Idling of the N52 Engine
Numerous forum users have expressed their dissatisfaction with the engine’s harsh idle and sporadic misfires. Slow starts and poor gas economy are other frequent symptoms.
These symptoms are similar to those of a VANOS solenoid failure, however the VANOS solenoid will set up an engine code. Spark plug and ignition coil replacements may be necessary if you don’t have an engine code. Engines with N52 engines normally need to have these parts changed between 50,000 and 90,000 kilometers.
Symptoms of a N52 Faulty Spark Plugs or Ignition Coils
- Rough idle is the norm
- Poor fuel consumption
- When it’s chilly outside, you may have trouble starting.
- Sluggishness or a decrease in power.
- N52 OEM Ignition Coils
- N52 OEM Spark Plugs
There you have it, the 7 common BMW N52 engine problems! If you cannot repair your N52 engine, then it may be time for a replacement. Engine Finder allows you to get in contact with a network of BMW scrap yards offering quality used BMW engines for sale!