VANOS Repair Question

[zielritter]

I'm mulling over a rebuild of the seals for the dual VANOS on my M52TU. From what I've read it seems the popular consensus is that the seals are well beyond worn by 30k miles. I'm at 71k with what is presumably the original seals.

However, my car runs smooth as butter and pulls hard through the rev range. I'm not experiencing any of most commonly noted symptoms of bad VANOS seals. What gives? Should I still go for the rebuild? Will I see any notable improvements in doing so?

As an aside, as I've been slowly working on rehabbing this vehicle I've noticed the suspension bushings are in exceedingly good shape for age and mileage. It has been garage kept and winter stored for at least the past 12 years. Don't know if this speaks anything to the VANOS seals though.

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[jclausen]

Working in the business for ever it seems, we hardly ever had to do vanos work, the typical e39 528 the problem would show up as a surging idle when the engine was cold, then would go away after a bit. I know there is a lot of talk about vanos, but we didn't have to deal with many issues around it. My car has 152k on it never had any vanos issues, runs great

[streetmaster]

I'm mulling over a rebuild of the seals for the dual VANOS on my M52TU. From what I've read it seems the popular consensus is that the seals are well beyond worn by 30k miles. I'm at 71k with what is presumably the original seals.

However, my car runs smooth as butter and pulls hard through the rev range. I'm not experiencing any of most commonly noted symptoms of bad VANOS seals. What gives? Should I still go for the rebuild? Will I see any notable improvements in doing so?

As an aside, as I've been slowly working on rehabbing this vehicle I've noticed the suspension bushings are in exceedingly good shape for age and mileage. It has been garage kept and winter stored for at least the past 12 years. Don't know if this speaks anything to the VANOS seals though.

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My 99 has the M52TU, which is undergoing a complete makeover, parked it at 170k, my motor ran smooth as well, PO did nothing to the car, so it was in need of the typical stuff, like bushings, shocks and struts, and a driveline clunking issue.
Had no intention on doing anything under the hood, but the exhaust bolts snapping off, lead me in that direction, although the motor did have a little rattle around the vanos, before it got parked, so I decided to take the plunge, and off the vanos came, but at 170k, they would've gone awhile longer, the pistons did slide pretty easy, but wouldn't drop like some of the videos show, but since I was already knee deep, I did that deal.
But what I did find, is that the timing chain tensioner spring was ready to be changed, purchased a new one, side by side, the new spring was a good 1/8" longer than the old one, so I figured if im changing that one, the upper secondary tensioner was getting replaced.

[Mr Bingley]

If it ain't broke don't fix it.

[Blacklane]

I bought my car used and I thought it ran fine, but after reading about the VANOS seals problem, I replaced mine. Man, what a difference it made at the low-end. Where I used to have to rev the engine on easy take-offs, now it could take off at much lower RPMs with more power. Apparently that is how it is supposed to feel. I should note that mine is a single-VANOS engine and it had 154K miles at the time.

Unfortunately there is no way to know if this will be your case until you do it and then say "wow" or "meh".

[mobilenet]

While a fun little project, Im not sure it made a noticable difference in my case and I ended up causing a few little issues by messing around with things.

I agree with Mr Bingley.

[cushjbc]

Unfortunately there is no way to know if this will be your case until you do it and then say "wow" or "meh".

I did a VANOS rebuild last month on my M54B30 - put me in the Wow column.