BMW E46 N42/N46 Valve Stem Seals – Replacement DIY Guide

BMW E46 N42/N46 Valve Stem Seals – Replacement DIY Guide

DIY Valve stem seals replacement on a BMW N42/N46 engine.

Engine suddenly started consuming a lot of oil (6 dcl/1000 km). I had some substantial oil leaks, so I first had to replace:

– oil pan gasket,
– valve cover gasket,
– Valvetronic motor gasket
– Valvetronic sensor connector flange,
– vaccum pump o-rings,
– VANOS solenoid o-rings.

I also replaced the CCV system, but nothing fixed the oil consumption problem. Replacing the valve stem seals was the next step…


Timing toolkit:

Flexible air valve holder:

Valve stem seal remover/installer pliers:

Complete valve spring compressor toolkit:

Service manuals:




BimmerZen says:

Also check out PART 1 of the more complete DIY guide:

gennaro dececco says:

Ciao.sono Gennaro dall'Italia.
Il tuo video e favoloso .
Volevo sapere come fare per costruire la chiave per comprimere le molle delle valvole.oppure si vende da qualche parte ?
Grazie un saluto.
Attendo risposta grazie di nuovo

bogysan465 says:

what is the pressure set on compressor by you in order to not let the valve go down!

Saif SWS says:

Where are you from?)

Adi says:

Do you put every cylinder on tdc when changing the valve stems or is it enough when the first is on tdc?

Andres varas says:

now is burning oil?¿?¿? less or nothing at all

Poanoofd says:

good video!

Me YuhMudda says:

Btw that video is legendary! You’ve done an amazing job.

Me YuhMudda says:

Guess my car is going by the mechanic, too many intricacies……….I’m fucked!

filip barac says:

Hey man nice video! I'm going to do the job myself, when i'm putting back the camshaft do i need special tools? I have the chain timing set do i need something else?

giancarlo bonazzi says:

good wrench diy. nice procedure and video

Meelis Liias says:

Awesome work.I had a same problem few years ago,but it was impossible to find any information on net or Youtube for N42 engine,so i let mechanic do it.He said he used some kind of shortcut,not sure what he meant.Anyway it worked and no more oil consumption for last 3 years.Keep up the good work.

feeesh. says:

Nice video! Subscribed 🙂 Did the ccv and replaced the vacuum pump on mine in January, was not much fun…

TheElemeh says:

Hey, nice job. Thanks for the video. Gretings form poland 🙂

mark n says:

Great job on changing out those valve stem seals. My beemer is not using much oil but it is passing a huge amount of oil through the ccv system where i have installed a catch can. If i do not recirculate the oil back to the oil pan the can will fill up over a few hundred miles. This is even with the catch can venting to atmosphere so there is not suction from inlet manifold.
I thought this might have been due to the stem seals but not to sure.

Any idea on why this might be? Also how to prevent so much creamy oil sludge.

Bartek Ż says:

Perfect job. Well done!

adixpogo says:

What is amount of pressure I need to apply, to avoid falling valve into cylinder? Good job!

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