VANOS... maintenance?

[timewarrior 3]

Hi, I don't want to sound like an idiot but here goes. Does anyone with VANOS equipped engines bother with this piston seal degradation thing I've read about? Supposedly the piston that responds to the oil pressure in the VANOS system has a seal that wasn't up to scratch and after 100000ish km the VANOS is not working at all or at least not working as it should.

After reading about it on the site of the people that sell the repair kits I thought I'd ask if anyone has has these problems.

Here's the site to the kit: http://www.beisansystems.com/products

[smiddy 76]

Pop onto performance Warrior. There is a sticky on the subject.

[allan 295]

Several of the members on here have carried out the Vanos overhaul. The yanks were raving about it a couple of years ago. Should your vehicle be having such problems get it checked over by someone that knows what they are doing first and be guided by them. Have found their are to many keyboard jockeys saying this and that and not knowing a thing, no experience gained by getting dirt under their finger nails first.

[duvey 245]

I have a slight rattle, and typical ~3k RPM bogging. Took it to HellBM in Silverdale and Lee(Leigh?) thought it was probably the VANOS, so I've ordered a Besian Systems seal and rattle fix kit. I'll let the pros do it this time, as I'm new to these engines, but the procedure doesn't look overly complex. There is certainly plenty of documentation on the net about it.

[Allanw 1051]

You'll probably be lucky to have them last 100K Ours was 117 K and 10/11 years??? Absolutely poked! The seals in mine didn't really seal any better than the piston did. Seriously - the piston actually fell out under it's own weight with the old seal. I could move the piston side to side in the housing, and it touched the sides and "clicked". The movement was easily seen with the naked eye.

It affects some engines more than others. The M52TU and M54 have double Vanos, and at least on the M54, it's infinitly variable - affects them a LOT, based both on what I've read, and what it did for our car. The low end torque was very noticable.

My Vanos Thread

[allan 295]

Glad to read you are getting it done by some one that knows whats what. Let use know the out come when it has been overhauled.

[Rgvkiwi 10]

Mine has a 3K hesitation and slight bog / very slight surging and am looking for answers too.

So I also look forward to hearing from you regarding the result and the cost...

The guys at Bellars Motor Works say they have NEVER needed to do a vanos repair as it is under so much hydraulic pressure it makes no difference if the seal is hard or not.....so I look forward to seeing how you get on.

Bellars found I had a consistant MAF error so I replaced that but hasn't made too much difference.

[duvey 245]

Its the rattle that is annoying me rather than the bogging (which is only very slight). As far as I understand, the S50B30 has vanos on the intake valve and not the exhaust valve, and is infinitely variable. Because it is not double vanos, I suppose it makes sense that the bogging isn't quite as pronounced.

Anyway - I'll let you know how much it costs me all up, and what the results are.

[swordfish 30]

Would be really interested to see the result!!! I was thinking of sending my Vanos to Dr Vanos, but might just go with the rebuild kit instead.

[elmarco 56]

It might suggest that poked Vanos is more a function of deficient maintenance and grubby oil than a deficient design?

I've often wondered that as I've never seen the same symptoms as described.

[Allanw 1051]

My E36 is at 220,000 km and has never had any work done on the Vanos system nor had my E39 at 298,000 km , both were regularly serviced at either Jerry Claytons or BM Workshop.

It might suggest that poked Vanos is more a function of deficient maintenance and grubby oil than a deficient design?

No, I think it's probably more likely related to the early Vanos not actually doing as much - it's basically only 3 stages, on only one cam. The M54 in particular, is prone to it, and they are infinitly variable between two points, on both cams. Apparently the 3.0 is affected more, and can actually stall from the issue, during cold idle.They use the cam timing to heat up the cats, and also reduce idle emmisions etc, depending on the engine temps etc. They have to make sudden changes upon opening of the throttle etc, and with the leaky seals, it takes longer for the oil pressure to overcome the leak. The exhaust cam is retarded during cold idle to increase the overlap, and heat the cats faster. Opening the throttle means it has to quickly alter the cam timing to provide more power.

Eventually, the seals can get bad enough to bring up fault codes, which is when BMW would fit a new/rebuilt Vanos unit. It was a problem in the US and UK, which probably have much better servicing regimes than the average NZer would stick to!

I'd wonder if doing the seals on yours would improve the power delivery? I have no experience with doing it on the earlier engines. The 3 stage thing is probably easier to control though, whereas on the M54, if it's constantly advancing the cams as revs climb etc, it may struggle to keep up with the rate of the revs rising??? It made the most difference at low RPM on ours though (possibly related to the lower oil pressure at lower revs?).

I think it's one of those things that people don't notice getting worse, like shocks or similar, because it happens slowly over time. Then when it's really bad, other symptoms show up.

I have been told BMW brought out software changes for the M54 to mask the symptoms too. I don't know if that's true, but some users on other forums reported better running after "software updates".

Our car has no build up under the rocker cover to suggest any problem with oil, or the changes. Even the entire Vanos assembly was immaculate - the O ring is the wrong material though - it was like all the plasticizers had come out, leaving a shrunken, hard o ring. I could literally snap it by folding it over. I'd be worried if they'd used the same material for something like the rear main seal! The only thing I've ever seen that bad, was valve guide seals of on old aircooled VW - they were probably 40 years old, and would have been hellishly hot on an aircooled head.

[_ethrty-Andy_ 2122]

The guys at Bellars Motor Works say they have NEVER needed to do a vanos repair as it is under so much hydraulic pressure it makes no difference if the seal is hard or not.....so I look forward to seeing how you get on.

Im certainly no qualified BMW mechanic, but isnt the same crowd in that E38 thread? Makes you wonder?

http://www.bimmersport.co.nz/forums/index....=45494&st=0

That said id take advice in person from a specialist over from the internet anyday, i learnt that trick a long time ago

Edited August 5, 2013 by _Ethrty-Andy_

[FRT 144]

Its the rattle that is annoying me rather than the bogging (which is only very slight). As far as I understand, the S50B30 has vanos on the intake valve and not the exhaust valve, and is infinitely variable. Because it is not double vanos, I suppose it makes sense that the bogging isn't quite as pronounced.

Anyway - I'll let you know how much it costs me all up, and what the results are.

I just did Besian systems vanos and rattle kit. my car 250k so much smoother variability 1000 - 3000+ rpm.

Mine needed rattle kit badly and was wabbly when i got piston spline out needed doing.

But i ordered S62 cup washer for behind sprocket hub as per besian notes. But NOTE you cant take sprocket hub off unless you take the exhust cam out, unlike 92 page besian instructions. i have a video showing hub wont come off in place.

This over haul did reduce my bad start up rattle but not gone completely due to warn tension cup washer on sprocket not applying tension.

[duvey 245]

I just did Besian systems vanos and rattle kit. my car 250k so much smoother variability 1000 - 3000+ rpm.

Mine needed rattle kit badly and was wabbly when i got piston spline out needed doing.

But i ordered S62 cup washer for behind sprocket hub as per besian notes. But NOTE you cant take sprocket hub off unless you take the exhust cam out, unlike 92 page besian instructions. i have a video showing hub wont come off in place.

This over haul did reduce my bad start up rattle but not gone completely due to warn tension cup washer on sprocket not applying tension.

Good to hear you had results. Hopefully this will minimize the rattle, my m3 is at 144k, so its possible the tension cup washer might not be so far gone - it might be worthwhile replacing the whole vanos at some point if it doesn't entirely rectify the problem.

Edit: spelings

Edited August 5, 2013 by duvey

[Docile 64]

hmmm im contemplating on this this as well.

my sister bought an e36 earlier last year and torque / power is weak at the low end <3k rpm. then picks up after that. 260k on it. it bogs down more noticeably when engine is cold. but when warm no bogging but weak power delivery below 3k.

also checked for vacuum leaks and it was all good. engine idles good as well.

ive done the oil change. no errors on diagnostic as well.

[wtbdeath 4]

The truth is , if your BMW is more than 60k , it is time to get VANOS seals replaced, yes, it will still function at 200k but not the way they are designed, if you are happy with performance drawbacks, you can leave it, the DIY only costs below $200