Replacing the vanos unit..

[Idle]

Hi diyanich.

1. Correct, one VANOS unit for each bank, mirror image.

On some M62TU'S (Mine especialy) the internal helical gears within the VANOS units become worn/loose over time. Mines done just over 100,000 miles. I'm inclined to think that previous owners have used the wrong grade oil. I am now using Silkolene Pro 'S' 5w-40 full synthetic. If you have an old unit off, it can be turned (With a rubiks cube type motion) with both hands quite easily. A new one is very stiff to turn.

2. Yes, valve cover gaskets on both banks (It will cure the 'oil in the spark plug wells' problem as well) and upper timing chain cover gaskets on both banks. Also, it's worth changing the main chain tensioner for a new one as the spring has been upgraded, ie: longer. No19:

RealOEM.com BMW E38 740i Timing - Timing Chain Lower P

3. Only a slight gain in mpg. But just to get rid of that embarrassing noise was enough for me. And, the relief that I'd found the real cause and there wasn't anything more sinister going on.

4. The dealers wanted in excess of £2000 as it would take more than 24 straight hours.........Yeah right!. I did it in 6 hours, admittedly, with the help from someone who had done it before on his E39 535i. So I would think it would take a good 8 -10 hours diy, taking it easy and making sure it's done right. The VANOS units themselves only take about ten mins each bank, the rest of the time is taken up with getting in there and putting it all back together again. If you can do the valve & timing cover gaskets you're 90% there anyway.

Have a look at this. Scroll down a bit to cn90's post and click on the Bentley Publishers pdf. It's for the timing chain replacement but gives the M62 VANOS diy procedure:

E39 540i - M62TU Timing Chain plastic guide disintegration - bimmerfest - BMW Forums


It looked pretty scary and technical to me, but really, it's very straight forward if you study it properly.

The VANOS units are dealer parts only. I paid £250 each.

The biggest drawback though is the special tools needed. Obviously the dealers will have them and maybe some indy's. Would they hire them out? Who knows? The other option is buy them:

BMW M60 M62 Master Camshaft / VANOS Timing Tool Kit on eBay.ca (item 350321859863 end time 28-Feb-10 21:51:47 EST)

The cam locks and impulse wheel timing jigs are essential for the job.

This is what my engine sounded like before I changed the VANOS units:

YouTube - M62B35 Ticking

Now she's nice and quiet.

Old:




New:




Oh!, and it also cured the 'start-up rattle' from cold..............bonus!