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BMW 5 Series 525i common faults.

2003–2007, saloon, petrol, 192 HP.

The fault list covers: M54B25 engine, GM5L40, ZF6HP-BMW, ZF6HP26 transmission.

What you save stays on this device only. My saves

6 fault write-ups. All are important. 1 recalls.

If you know the year, pick it. Faults for other years drop out of the list.

Before you buy

Known faults

6 important faults

critical2

M54: the crankcase breather valve sticks, its lines break and oil is used up

critical

The crankcase breather valve and its four lines often fail. The valve sticks open and the lines break, and both let false air in. The valve and the lines last between 110,000 and 200,000 km and typically fail around 150,000. In cold weather the fault develops faster, because the condensing vapour freezes in the valve and blocks it. The symptoms are oil being used up, a rough idle and blue smoke, and a dense vapour can also appear at the front under the bonnet. If the drain of the valve blocks, the burnt oil mist also leans out the mixture and the engine fault light comes on. Left untreated it can end in engine damage. There are two tests for it, and both can be done at a viewing. With a warm engine at idle, lay a flat plastic bag over the oil filler opening. If the bag stays up or is only drawn in by 2 to 3 cm, the valve is fine. If it is drawn in strongly, the valve has stuck open. With a cold, stopped engine take the breather line off at the front corner of the cam cover and blow into it: you should hear bubbling in the sump. If you do not hear it, one of the lines has broken or the drain in the dipstick tube has blocked.

between 110,000 and 200,000 km

What to check

  • With a warm engine at idle lay a flat plastic bag over the oil filler and watch whether it is drawn in
  • With a cold engine blow into the breather line: there has to be bubbling in the sump
  • Ask how much oil has to be added between two changes
2 more steps in the write-up

M54: the DISA valve breaks and its parts can enter the engine

critical

The DISA valve is the black box on the side of the intake manifold, and it adjusts the length of the intake so that there is more torque at low revs. The shaft of the valve breaks at its base, and then the flap falls off: the pieces can get into the engine and cause major damage there. Its membrane can tear separately as well. The symptoms are juddering on acceleration and a noticeable loss of power, and the valve can also hiss loudly after the engine is switched off. The seal of the intake connection is cast into the DISA, and as it shrinks it lets false air in. Its condition can be checked with the valve removed. The flap has to turn against resistance, spring back when released, and have no play. With the vent hole at the bottom of the round valve held closed, a flap moved by hand may only spring open to 45 degrees and then has to stop. With an aftermarket DISA the experience is that the trouble is back after a year, so a repair kit or a reconditioned factory part is the better choice.

above 120,000 km

What to check

  • On acceleration watch for juddering and loss of power at low revs
  • Switch the engine off and listen for hissing from the side of the intake
  • Ask whether the DISA has been touched, and whether it is a factory, reconditioned or aftermarket part
2 more steps in the write-up

expensive4

M54: worn VANOS seals and a cold rattle

expensive

The seals in the camshaft adjuster (VANOS) age, and the rattling noise is most noticeable from cold, right after starting. The noise fades or disappears as the engine warms up.

Show the rest

With worn seals the cam timing becomes imprecise, which leaves the engine flatter low down and raises consumption. The fault appears between 60,000 and 150,000 kilometres.

between 60,000 and 150,000 km

What to check

  • Start it from cold and listen to the first minutes: the rattle comes from the camshaft area
  • Watch whether the noise fades as it warms up: that is typical of VANOS
  • Accelerate from low revs: flat running points the same way
1 more steps in the write-up

ZF 6HP automatic: mechatronics connector sealing sleeve leaks

expensive

In the ZF six speed automatic (BMW codes GA6HP19Z / GA6HP26Z) the electrical connector of the valve body control leaves the gearbox housing through a plastic sleeve. That sleeve and its seals age, and they let oil through.

Show the rest

The symptom is irregular shifting, a gear slipping at higher revs, limp mode, a drivetrain fault code and a message on the display. The cause is the same in each case: the leak drops the hydraulic pressure, and the valve body cannot close the clutches with enough force.

The sleeve can be replaced without removing the gearbox, you only have to drop the oil pan. If it leaks for a long time, the slipping clutch and the overheating pump take the inside of the gearbox with them, and from then on it is a rebuild. The factory calls the oil a lifetime fill, but in practice the sleeve wears out around 60,000 to 70,000 miles, roughly 100,000 to 115,000 km.

between 100,000 and 200,000 km

What to check

  • On a lift look at the right side of the gearbox housing, above the oil pan: a wet, oily connector is the characteristic picture
  • On the test drive watch the shifts cold and warm: jerking, delay, slipping at higher revs
  • Ask for a fault code read from the gearbox controller: gear ratio fault, pressure regulation
2 more steps in the write-up

Water pump: a worn bearing, a disintegrating impeller, overheating without warning

expensive

The impeller of the belt-driven water pump is made of plastic, and if the blades break apart, there is nothing left to circulate the coolant. The belt keeps driving the pump, but the engine gets no cooling and heats up quickly.

Show the rest

This fault is dangerous because it gives no advance sign. There is no warning signal from a disintegrating impeller, and the engine temperature runs up faster than the gauge can follow; by the time it shows, the cylinder head can already be damaged. The breaking impeller is a fault of its own on the six-cylinder built between 1992 and 1995, which is why the maker went back to a metal impeller, and then used a composite impeller in the later engines, which proved more durable. A pump with a metal impeller is still available today, as a durability replacement.

There is, however, one sign that can be caught before the failure: play developing in the shaft of the pump. That means the bearing is wearing, and because the impeller sits on this shaft, play in the shaft signals the coming end of the pump. With the belt off it can be felt by hand.

On the M54 it appears at around 120 000 and on the N62 at around 150 000 kilometres. Once the engine has overheated, the consequence stays: a warped cylinder head and a damaged gasket are no longer put right by replacing the pump.

between 120,000 and 150,000 km

What to check

  • With the belt off take hold of the water pump shaft: play means the bearing is wearing
  • Watch the temperature gauge both while driving and at a standstill: it should not climb above the usual
  • Ask when the water pump was replaced, and whether with a metal or a composite impeller
2 more steps in the write-up

M54: a failing VANOS solenoid valve and fluctuating revs at low rpm

expensive

The VANOS solenoid valves fail sooner or later, and that gives fluctuating revs and a noticeable loss of power at low rpm, sometimes starting trouble as well. The valve itself is not always the fault: the contacts of the connector can widen or oxidise, and then there is no proper contact. An aged camshaft or crankshaft sensor can cause the same. Oil can seep along it into the wiring harness, and capillary action carries it towards the control unit. From there a VANOS fault code, a lambda fault and misfires can follow. A widespread misconception is worth stating here. The rattling heard on a cold start is NOT an indication of the condition of the VANOS: the noise comes from the play in the needle bearings, which every VANOS has, only not every drivetrain resonates with it. Anyone who concludes the VANOS is fine because it does not rattle is concluding wrongly.

What to check

  • At low revs watch for fluctuating revs and a lack of power
  • Read the fault memory and look for the camshaft timing codes
  • Do not judge the VANOS by the cold rattle, because that is not what it indicates
2 more steps in the write-up

Checklist

BMW 5 Series 525i

First what you would check on any car. Then the faults of this model.

Before you buy

Checklist

The printed sheet starts with what you would check on any car. What you tick stays on this device only.

On every car

Ask the owner

Faults of this model

vinkodex.com · Before you buy it, see what can go wrong.

Official recall1 recallsShow

The manufacturer fixes these for free at a franchised dealer. Ask with the VIN whether it was done.

A12/0484/19Safety recallInjuriesno date · EU Safety Gate

Owing to retrofitting of the steering wheel, certain vehicles may be equipped with a driver airbag that has a gas generator which could burst in the event of airbag activation if it has been exposed to moisture and heat cycles over time. This may result in metal parts being discharged, which could lead to injury or death of the vehicle occupants.

Remedy: Type of economic operator taking notified measure(s): Manufacturer Category of measure(s): Recall of the product from end users Date of entry into force: Unknown

The authority's notice

Engine and transmission

1 engines · 3 transmissions

M54B25 · 2.5i

141 kW (192 HP) · petrol

GM5L40 · 5-speed automatic, longitudinal (GM 5L40-E / A5S 360R)

automatic · 5 speed

Torque limit400 Nm
MakerGM

We built the code from the model and the gear count. The factory sheet does not state it. More than one transmission is possible. The gear count does not tell them apart. The code is on the side of the transmission.

Variant data

What is in this version

Factory data

Trim
525i
Body
saloon
Fuel
petrol
Transmission
automatic
Engine size
2494 cc
Power
141 kW (192 HP)
Drive
RWD
Production
2003–2007

Factory service interval

The manufacturer specifies this for this version. Of the mileage and the time, the one that comes first is the one that counts.

  • Air filter

    • 60,000 km or 4 years

  • Cabin (pollen) filter

    • 30,000 km or 2 years

  • Brake fluid change

    • first: 3 years, then 2 years(first change at 3 years, then every two years)

  • Engine oil and oil filter (BMW condition-based service)

    • LongLife25,000 km or 2 years

  • Spark plugs, petrol

    • 60,000 km or 6 years
All E60 versions

Information, not an expert opinion

We write the descriptions, and we put the source next to them. A person reviews them before they go out. They are still information, not a technical expert opinion.

  • A fault on the list does not mean the car you are looking at has it.
  • A fault missing from the list does not mean the model is fault-free. Write-ups are made model by model. Not all of them are done.
  • You decide whether to buy. This is no substitute for an inspection. That needs a workshop and a history check.
Details in the terms