The BMW N62 V8 engine found in the E60 5 series, E63 6 Series and the E65 7 series engines has a common problem of smoking after idling for a few minutes. The seals become hard and brittle and start letting oil past the stem at idle when the vacuum is high - normal driving is generally ok. But when they are getting bad, even pulling away after waiting at the lights leaves an embarrassing cloud of smoke.

The official approach is to remove the heads and replace the valve seals, which in the UK costs between £1250 and £2000 at an independent dealer. (See page 3 for contact details)

The AGA Valve stem seal kit allows you to change them in situ saving lots of time and cash. The main problem is that the tool costs $900 which is around £800 once landed here in the UK. See page 3 for rental options.

My car has done about 117k miles and is steadily getting worse - so time to change the seals using the AGA tool, which is expensive but high quality.

In addition to the usual tools, you are going to need a few special tools:

1) Long nose “hose” pliers to remove the valve stem seals. (Item 1 Item 2)

I had an existing pair which I heated up and bent from 45 to 90’ angle, which did a number of them, but I couldn’t get it onto cylinder #4 - so I purchased a selection of them, which did work without modification:

2)E-Torx E6 star socket

3)T25 Torx

4) Compressor to supply the leakdown tester

5)Leak down tester or adapted compression tester - this is used to pump compressed air into the cylinder to keep the valves closed - I purchased this one:

This particular leak down but I found it only put 15 psi into the cylinder, so I just used the hose and fed it directly into my regulated 80 PSI air supply for my workshop.

6)USB Endoscope or small camera.

On my 750 I couldn’t even see the inlet valve for cylinder #4 which is close to the bulkhead - so I purchased a USB endoscope which worked perfectly.

7) I purchased Elring OEM spec seals in the UK from Andrew Page, cost about £120.

The valve stem seals are part number 199.440 for a pack of 16, you needs two packs for the engine.

The rocker cover gaskets are Elring part number 725.340 (UK Nearside Cyl 5-8) and 725.330 (UK Offside Cyl 1-4)

They fit the following N62 V8 based cars:

BMW E60/E61 540i,545i,550i

BMW E63/E64 645Ci,650i

BMW E65/E66 735i,740i/LI,745i/Li,750i/Li

Here’s all the partnumbers which includes the front timing covers and vanos solenoids which you should change:

Part Number Description QTY

11127518420 Ecentric sensor seal 2

12141748398 Rear cam sensor seals 4

11127570219 Spark plug tubes 8

7119903596 Servo o-ring 2

11147506419 Offside front timing case gasket 1

11147506424 Nearside front timing case gasket 1

11367546379 Front cover solenoid o-ring 4

11367513222 Front cover solenoid o-ring 4

11667509080 Vacuum Pump o-ring 1

11127541887 flange nut 1

11127541887 torx bolt 2

E-Torx E6 Socket Long Nose hose pliers Leakdown tester, modded to 80psi

All German Auto (AGA) BMW N62 V8 Valve Stem kit.

The tool comes with good instructions and there’s also a video on their site showing how to use it - however it starts at the point of taking the rocker cover off - the pictures below will show you how to get to that point.

Remove the air plenum at the front - ensure you disconnect the vacuum pipe to avoid snapping the nipple of the plenum.

Remove the pollen filters and then remove the ducting leading into the car - there’s a little metal clip on the top.

Now remove the bulkhead - there are a couple of bolts at the front and a T25 torx at the back.

At every opportunity use a vacuum to remove dirt and leaves, you don’t want any of this dropping down into the rocker covers when you remove the,

Disconnect the gas struts and prop the bonnet up. It will go almost vertical and give you more room and light.

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