2019-04-01 BMW Car

APRIL 2019 73

WORKSHOP WISDOM

Here’s an M47N engine in a 2006 120d that’s covered

160,000 miles. This unit was derived from the M47

136hp 2.0-litre 16-valve diesel, launched in 2000.

That engine was revised to become the M47N in

September 2001.

The first job is to remove the under-bonnet plastic

panelling covering the engine, that houses the pollen

filter. On a 1 Series like this (as well as on the E90 3

Series and the 520d), four 8mm bolts will need to be

removed and this is what you’ll find underneath.

1

2

light on the dashboard.
At the same time, you should also clean
up the EGR valve as well as the manifold/
head ports. In the majority of cases,
these will be found to be coked-up now
to such a degree that both performance
and economy will be suffering. This article
really covers tackling this work on the
later 1 Series and E90 cars, but E46s are

similar, and remember that the 318d and

118 cars don’t have swirl flaps.

Lots of places sell swirl flap alloy

blanks, such as X8R Improved Vehicle

Components (x8r.co.uk), and you’re

looking at around £30 for a set of blanks

and new rubber gaskets. The new gaskets

are very rarely required, though, and I’ve

never actually had to fit new ones.

The 1 Series and E90s have two strut top reinforcing

bars running from the strut towers to the bulkhead.

Remove these by undoing the T20 bolts on the struts

tops, as shown here, followed by the centre bolt. The

outer bolts will need to be torqued-up later to 60Nm.

3