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BMW 3 Series 316i Executive common faults.

2001–2005, saloon, petrol, 115 HP.

The fault list covers: N42B18, N46B18 engine.

What you save stays on this device only. My saves

3 fault write-ups. All are important. 3 recalls.

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

Before you buy

Known faults

3 important faults

Electric water pump: silent failure, immediate overheating

critical

In these engines the water pump is not belt driven but has its own electric motor. It gains on fuel consumption, but it opens a new failure path: the pump or its electronics often simply stops with no warning. Measured in the official complaints, the typical mileage is 161,000 km (a tenth of the complaints already at 81,000, a tenth only above 257,000 km). So the common wisdom of "around 100,000 km" is early: most of the failures happen between 130,000 and 250,000 km.

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With a belt driven pump the flow weakens gradually, here the circulation stops in an instant. In urban traffic the temperature crosses the limit within minutes, the cylinder head distorts, and the repair is an engine rebuild.

Replacing a still good pump at around 120,000 to 150,000 km costs less than repairing an overheated engine. If the replacement is already in the service book, the pump has already been changed.

between 81,000 and 257,000 km

What to check

  • Watch the coolant temperature gauge after startup: it should settle evenly, not jump around
  • Standing still with a warm engine, listen for whether the cooling fan and the pump are working
  • Ask for a fault code read: codes pointing at coolant flow belong here
2 more steps in the write-up

E46: the plastic parts of the cooling system (expansion tank, water pump impeller)

critical

The E46 cooling system uses many plastic parts, and they age from heat and pressure cycling. Two parts fail often.

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The expansion tank cracks and breaks: often with no warning, while driving, and the coolant is gone within minutes.

The impeller of the water pump on the six cylinder engines is plastic, and it often breaks between 100,000 and 160,000 km. The circulation then stops, and the broken pieces scatter through the system: the repair does not end with replacing the pump.

This is not a factory defect but the nature of the design: on the E46 the cooling system is a wear item. If the service book shows no replacement, count on changing the plastic tank and the water pump. Repairing the cylinder head of an overheated six cylinder costs a lot, and it can cost more than the car.

between 100,000 and 160,000 km

What to check

  • Open the bonnet and look at the expansion tank: hairline cracks, whitish discolouration, traces of a leak
  • Check the level and colour of the coolant: brownish, cloudy fluid is a bad sign
  • After a cold start listen around the water pump: a metallic whirring or squealing is suspect
2 more steps in the write-up

E46: cracking rear subframe mounts

critical

A known structural fault of the E46 is the rear subframe mounting. The sheet metal of the rear axle carrier cannot take the twisting load of the subframe and the differential: the floorpan cracks around the mounting points, and in extreme cases the mount tears out of the body.

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The phenomenon affects the entire 1999 to 2006 series, and it does not depend on mileage: it occurs on low and high mileage cars, and on standard and modified ones alike.

The inspection is hard. The crack is often only visible once the subframe is removed, It is easy to get a "no crack" result if they do not look where the metal cracks. The maker's foam filled repair was short lived; the durable fix is welding in reinforcement plates.

What to check

  • On a lift or over a pit, inspect all four mounting points of the rear subframe, all around, on the floorpan
  • Look for hairline cracks, creasing and cracked paint in the sheet metal around the bolts
  • On an uneven road listen for knocking and squeaking from the rear
2 more steps in the write-up

Checklist

BMW 3 Series 316i Executive

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 recall3 recallsShow

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

Most recent: 7 May 2013

A12/02024/23Safety recallInjuries7 May 2013 · EU Safety Gate

The propellant in the passenger airbag can deteriorate due to high humidity and temperature variations. In the event of an accident in which the airbag deploys, this could result in fragments from the inflator casing coming loose and injuring the vehicle’s occupants. The product does not comply with the Regulation on the approval and market surveillance of motor vehicles and their trailers, and of systems, components and separate technical units intended for such vehicles.

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: 07/05/2013

The authority's notice

A12/00017/19Safety recallInjuriesno date · EU Safety Gate

The gas generator on the driver side airbag could burst in the event of airbag activation if it had been exposed to high air humidity, high temperatures and considerable temperature fluctuations over several years. This could result in metal parts being discharged, increasing the risk of injury of the vehicle occupants. No information

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

A12/0266/17Safety recallInjuriesno date · EU Safety Gate

If the driver's airbag is deployed, the inflator might burst if it was subject to high air humidity, high temperatures and substantial temperature fluctuations over a number of years. This may result in the ejection of metal parts, which could cause injury or death to the driver and the passengers.

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

2 engines · 0 transmissions

N42B18

85 kW (116 HP) · petrol

We built the code from the model and the gear count. The factory sheet does not state it. More than one engine code is possible. The fault list shows the faults of each.

Variant data

What is in this version

Factory data

Trim
316i Executive
Body
saloon
Fuel
petrol
Transmission
manual
Engine size
1796 cc
Power
85 kW (116 HP)
Drive
RWD
Production
2001–2005

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 E46 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