Morning Scott,
I was of a similar opinion with my wife's 53-plate 2.5i auto.
Then the water pump packed up so I decided to do the lot in one go.
Yes, the kit costs a fair bit, but it comes with everything, including new gaskets and if you can do it yourself there's no other cost.
I was sceptical, and when it first started up I thought I'd broken it as it ran rough for 30 seconds or so.
Basically, as the seals fail, the oil sneaks past them and doesn't push the pistons, so the cams don't get adjusted. this is masked by the ECU compensating (known as adaptations). So when you fix it, the ECU has to learn all over again. I speeded up that process by resetting the adaptations with my code reader, taking it back to a default baseline.
In short, initially you'll notice the car seems to run smoother. You may not immediately be aware of a huge change in performance, but over the next 100 miles or so, as the ECU learns to live with the new vanos, the car will just get better and better.
On Vall's auto it was most noticeable that gear changes became much smoother, which I put down to the fact you've recovered a lot of torque.
Don't expect it to feel like you've supercharged it of course, but you will notice the car becomes much more pleasant to drive.
It is one of the first jobs I do now on any of the Z4s (M54) that I get.
Of course there's an assumption you'll be doing it yourself? If not then the price is going to go up a fair bit at a garage.
Whereabouts are you?
I'm in the middle of Norfolk and have done a few. I would leave it to you to decide how much my efforts were worth.
Likewise, there's Stuart (bigwinn) in Lincoln who has done loads.
Probably others around the country too.
When I did my first one Stuart was on speed dial and helped out with a few hints and tricks. I'd happily offer the same support to you if needed.
If you don't do it you'll never know what you're 'mything'
