BMW 325i Engine

BMW 325i Engine -Complete Guide

The BMW 325i Engine is an engine that has been in production for more than three decades. Many BMW enthusiasts consider the 3-Series to be the brand’s heart and soul as a driver-focused sedan with seating for four that can come alive on twisting roads when commutes get interesting. It’s the direct descendant of the BMW which launch in the 2000s, which made the company renowned.

BMW 325i Engine was started manufacturing in the early 2000s. It belongs to the E90, E91, E92, and E93 generation 3 series. It’s a makeover for the. It’s a four-door, five-seat midsize saloon with rear-wheel drive and a front-engined front engine. The naturally aspirated 3 Litre 24v Inline 6 petrol engine (BMW N53B30) produces 215 BHP and drives the 325i to 62 mph in 6.7 sec with a max speed of 155 mph. It comes with a six-speed manual or a six-speed automatic gearbox.

Table of Content

  • Engine Specifications
  • History of 325i Engine
  • Problems of BMW 325i Engine
  • Conclusion

Engine Specifications

The 325i is the engine with the 6-cylinder in the lineup. With a 0-60mph time of 8.8 seconds and a peak speed of 142mph, it’s smooth and quiet but fun to drive. The 325i is one of the finest engines in the lineup, with a 0-62mph time of 7.4 seconds with a top speed of 152mph. 

The BMW 3 Series 325i Sedan was the top-of-the-line version in the 3 Series range from 2007 to 2009. This 325i Sedan model is a 2.0-liter engine that produces 215 horsepower and 246 pound-feet of torque. The automatic gearbox is offered for the BMW 3 Series 325i Sedan. This engine generates a maximum torque of 250 Nm (184 lb. ft) at 2750-4250 rpm and a maximum power of 218 PS (215 bhp – 160 kW) at 6500 rpm. The rear-wheel-drive (RWD) with a 6-speed manual transmission delivers the power to the road.

History of 325i Engine

In the beginning, a new version of the venerable 3 Series arrived, bringing with it engine upgrades like dual-overhead-camshaft designs and four-valve cylinder heads. The 3 Series also received BMW’s VANOS technology, which allows for variable valve timing to increase power and efficiency. The top-of-the-line engine for the generation was a 193 horsepower inline-six. Two new turbodiesel six-cylinder engines introduce.

Later, BMW adopted direct injection on the fourth-generation 3 Series with a four-cylinder diesel engine that produced 136 horsepower and a peak speed of 128 mph while returning up to 41 miles per gallon. BMW updated their valve-timing system for gasoline engines to Double VANOS, which allows for even greater management of pollutants and torque output. The 325i got a slew of technological upgrades, including multivalve heads, direct injection, and a variable-turbine turbocharger, which combined to generate 184 horsepower and a peak speed of 141 mph.

The 325i gasoline engine was in the market with the fifth-generation 3 Series. Common-rail injection and a variable-geometry turbocharger were added to the engine, boosting output to 163 horsepower. The 325i gained 218 horsepower, thanks to a redesigned magnesium-aluminum crankcase that allowed the inline-six engines to save weight. The 325i, which debuted in 2007, was the next significant step forward in 3 Series engine development. Its 3.0-liter twin-turbocharged engine produce 306 horsepower and was immediately adopted by other BMW vehicles.

Problems of BMW 325i Engine

Leaking Oil Filter Housing Gasket

The most prevalent fault with all 325i engines is leaking oil filter housing gaskets, and you’ll be hard-press to find one that hasn’t had this issue at some point. There are two gaskets in the assembly. One connects the oil filter housing to the engine block, while the other connects the housing to the oil cooler. These gaskets grow stiff and brittle over time, causing an oil leak. Gaskets are inexpensive, and replacing them is simple.

VANOS Solenoids

Vanos, or variable valve timing, is standard on all 325i engines. Although the system is dependable, oil sludging can cause difficulties with two solenoids that control valve timing. Running problems, a lack of low-end torque, and an illuminated check engine light will result. Solenoids are simple to remove and clean.

Valvetronic Stepper Motor

These engines also include a Variable Valve Lift system called Valvetronic in addition to Vanos. The amount of intake valve lift is controlled by a stepper motor and a set of levers. The sole common failure point, despite its complexity, is the stepper motor itself, which might seize. BMW employs a sophisticated crankcase ventilation system that includes a series of separators and a diaphragm that regulates crankcase pressure. Large quantities of oil vapor will leak into the intake manifold if this diaphragm ruptures, generating blue smoke from the exhaust and excessive oil consumption. Although the diaphragm is not available as a replacement component from BMW.


Electric Water Pump Issues in 325i Engine

An electrical coolant pump is used in all six-cylinder engines, and its speed is determined by the engine temperature and load. The coolant pump’s electric motor might malfunction over time, resulting in engine overheating. Although a new pump is costly, replacing it as a preventative precaution for vehicles with high mileage is the best option.

High-Pressure Pump on Turbocharged Engines

A high-pressure fuel injection system is used in turbocharged engines, and it has two main failure sites. One is a high-pressure pump, which causes a lot of hesitancy, lack of power, and slow acceleration, especially in early versions. Another issue that might arise is blocked fuel injectors, which can occur if the automobile is driven on low-quality fuel. Additionally, turbochargers can leak oil inside, though this is not a typical occurrence.


As the BMW 325i engine appeared to be slow in early versions, it was somewhat improved over time. As the torque rose, so did the power, and the mileage even matched that of BMW’s newer models. The 325i variant’s upgraded engines generate fresh thrust and demand among consumers. The engine was good, but it had difficulties like any other automobile, yet it was popular at the time.

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