About to rebuild a VANOS - any special warnings?

[gmushial]

It looks like tomorrow will be the day of infamy - time to rebuild the VANOS ('99 2.5L dual VANOS, 147k miles and more gutless at low revs by the month)... it's been on the to-do list for a while, and it's time to move it to the done list. I have the seal kit, have all the gaskets, pretty sure I understand the procedure... but having never done such before, and understanding this isn't an "easy" job: anyone that's done their's - any special heads up, warnings, hints? I'm assuming this will be an all day job.

[328 Power 04]

Are you using this procedure?

http://www.beisansystems.com/procedu..._procedure.htm

I've done the E36 single vanos rebuild and it's WAY more involved than the dual vanos. E36 you have to re-time, etc etc.

Even then the E36 one took about 4 hours.

[ZGator]

Sorry no input here, I am about to do the same myself - please let us know how it goes, and your opinion on how much improvement was gained. I was not sweating doing it too much - but with a good running engine - good mpg - not a single leak, I am not dying to do it yet. I was almost thinking of doing the CCV while in there. I do have new intake O2 Sensors I was going to do as well.

[gmushial]

Are you using this procedure?

http://www.beisansystems.com/procedu..._procedure.htm

I've done the E36 single vanos rebuild and it's WAY more involved than the dual vanos. E36 you have to re-time, etc etc.

Even then the E36 one took about 4 hours.

Yup, their parts and their procedures... and yes, grateful for a dual vs single ... w/re time it sounds like allocating a full day isn't a bad choice.

Sorry no input here, I am about to do the same myself - please let us know how it goes, and your opinion on how much improvement was gained. I was not sweating doing it too much - but with a good running engine - good mpg - not a single leak, I am not dying to do it yet. I was almost thinking of doing the CCV while in there. I do have new intake O2 Sensors I was going to do as well.

Sounds like we have the same to-do list, though I'm doing the VANOS first, will the others afterwards. "Great minds think alike" ???

[ZGator]

Sounds like we have the same to-do list, though I'm doing the VANOS first, will the others afterwards. "Great minds think alike" ???

yeah, the last thing I did was my Guibo - and I had to remove the exhaust (I recall you did this right before I did as well) - and like your experience the exhaust manifold bolts were the fun part.

One good thing about doing things separately is you get a feel for what did what, better response, mpg etc..

[Bimjam96]

There's a few YouTube videos too if you haven't looked yet, might help

[FinnNiks]

It looks like tomorrow will be the day of infamy - time to rebuild the VANOS ('99 2.5L dual VANOS, 147k miles and more gutless at low revs by the month)... it's been on the to-do list for a while, and it's time to move it to the done list. I have the seal kit, have all the gaskets, pretty sure I understand the procedure... but having never done such before, and understanding this isn't an "easy" job: anyone that's done their's - any special heads up, warnings, hints? I'm assuming this will be an all day job.

Good luck, hope it goes well! This is on my to do list

[Blacklane]

The Beisan Systems instructions are amazingly simple to follow, but it is still an involved process.
I recently did this and have the following comments:
1. Make sure you have all of the tools on hand. Beisan has a complete list of them. I had to go out and buy a set of external Torx sockets for the camshaft sprockets. Of course for the single-VANOS you also need the special cam and crank holding tools. You need a torque wrench good for at least 30 N-m or so. You need some RTV. If you're adding the VANOS rattle fix, you need the special Beisan socket and vice jaw liners.
2. This is the perfect time to replace the valve cover and spark plug gaskets plus a new set of plugs.
3. The Beisan torque value for the injector ground strap (M6) bolts is way too high and I broke one of them. The torque value they give is for the M8 bolt that has the M6 stud on it.
4. If you are disassembling the VANOS to do the rattle fix, use the special Beisan-modified socket, get it seated, and apply LOTS of pressure before attempting to turn the wrench. The bolt head is thin and the socket wants to round off the corners while twisting off of the head.

[The ZED]

straight forward procedure, will make your motor run smooth.

[ctlynch]

I did the Beisan rebuild on the dual VANOS on the M54 in my e39 530i. It took the better part of a weekend, but was uneventful. While I did it, I also replaced the valve cover gasket and all of the plugs. Worked great. Good luck.

[gmushial]

It turns out today is the day to do said surgery... actually in the middle of it presently.

So far it's been about an hour and twenty minutes to get down to having the VANOS exposed, ie, the valve cover off. The most difficult part so far has been actually getting the valve cover to let go. But short of that, lots of 8mm and 10mm nuts. but nothing special. The Beisan procedure has been spot on.

The other comment I'd offer - will upload pics when I'm done - is that the cam gallery is spotless, I mean spotless, not a deposit anywhere. Likewise the bottom side of the valve cover. I was expecting for 150k miles that I'd find at least some deposits - zilch, zero, noda. Is this an artifact of the AMSoil ??? But I've never seen a gallery so clean in all the wrenching I've done over the decades (on cars with anywhere near the miles). The only tipoff that there are miles on this motor is the wear patterns on the cam lobe tips... otherwise, if you told me the motor had 5k miles on it I'd believe it.

after a lunch pause:

The VANOS is out. Only "difficulty" (on a difficulty scale of 1 to 10, a 1.0001) was pulling the piston seal plugs - couldn't see inside from the front to see the ribs to grab... but they're both out.

Do think the seals are toast, ie, the intake piston will slide from the back of its bore to the front, by simply flipping the VANOS over - would like to believe there should be more seal than that ;-) ;-(

will have to take another pause - have a division dean that wants to talk on campus about software for the fall semester... so time for a quick shower, get prettied up and head into town. But bottom line so far: about two hrs to get VANOS out and on top of the workbench... don't want to say it too loudly - but might have this running by tonight (did I say that... hope I didn't say that ... but we shall see)... time to go hear what they've paid us. Hopefully back in a couple hrs.

[MissileMech]

Yes it is the Amsoil - I used it to clean and keep my Bronco 302 motor clean (notorious for gunking up and mine was really gunked up when I bought it).

My suggestion for the vanos is to use silicon grease for reasembly. It works really well with those seals when installing the pistons.

[Wojtek79]

I have about a dozen E36 single vanos units at home. I rebuild cylinder heads so these come with the head when I pull it. Maybe at the next IL area Fix-it-Day we can do a vanos rebuild class. lol

[gmushial]

YES YES and YES (assuming the question is: to replace or to not replace a VANOS' seals) - it is so nice to have low-end torque again.

I spent more time at SC talking software than expected... but still got the VANOS done, reinstalled and test-fired, before dinner Since the project was interrupted multiple times it's hard to give a good estimate in terms of time - but I would guess btwn 4.5 and 5 hrs. In terms of the actual job, I'd rate it on par with doing the guibo (assuming one uses the by-the-book method (drop exhaust etc)) - and I'd much rather do the VANOS than the guibo.

To pickup from my previous posting: doing the seals on the VANOS itself, is a cakewalk - probably the easiest part of the job, probably the most fun also. Since yesterday was in the upper 90's (and I was working outside on the driveway in front of the Z), there was no need to warm the seals. Cutting the old seals out was a bit harder than I expected since they had turned into steel like plastic, ie, there was not a chance in hell that they were going to provide any sealing [the pistons actually had laterial slop btwn them and the bores ]. Putting the new o-rings in was a 30 second job. Putting the teflon rings on top was like a minute each - they eased in with no problems. Sizing them back in the bores was a nothing - on the big ends they went in on the 2nd try, on the small ends on the first try. All said and done: maybe 20 minutes total to replace the seals (and this was a double VANOS, on a '99 M52TUB25).

Putting the VANOS back in was the only stumbling point - and nothing to do with bimmer and their design, but because of POS harbor freight tools. [I didn't trust my hands to judge 5ftlb on the allenhead/torex head bolts which tie the VANOS pistons to the cams - so had the wife pick up a HF 1/4" torque wrench. Set it to 60inlb and torqued away, waiting for the click. It never clicked. By my hand the poor bolt got 30ftlb worth... actually what stopped me was I could feel it start to give. So I pulled it out and used one of the new replacement one I had gotten, just in case. Pitched the torque wrench about halfway across the yard (had to explain this morning upon returning it how it got so dirty )... and found a 1 gal water bottle, dumped out 1/4 of the water, leaving 6lbs worth, calibrated the arm as to what 6lbs felt like, and torqued the bolt with a 1 ft long breaker bar - I suspect I got close. On the second piston to cam bolt good old HF got me again. This time the T30 bit came out of the socket and fell somewhere. It was the only T30 bit/socket I had. So spent 20 minutes with air, light and magnet trying to find it. Was about to have the wife head into town to get another one when I found it wedged into the radiator support. I put the bit back into the socket base + some superglue + tightened the set screw... hopefully the SOB will never come lose again.

After those dances everything else went well/smoothly. I replaced every gasket I had access to in the process of this dance. The sparkplug seals were about as soft as the VANOS seals, ie, concrete like, or steel like; likewise the valve cover gasket - it came off in about ten pieces. Also replaced all the bolt seals - they're weren't as bad, but they were ready.

After my impromptu workbench I'd setup in front of the hood was empty of parts... I covered the driver seat with a old bed sheet, inserted the key and gave it a twist. It came to life immediately, and other than hearing the oil being pumped into the VANOS cyls, it sat there and idled smoothly (no idle hiccups like before). Hot damn. I let it idle and checked around for any oil leaks/seeps etc. None found. Since the wife was wanting to know if I wanted dinner then, or later, I chose then, did a quick drive around the loop which runs around the house, shop and the front gate. Just in that it was obvious there was an improvement. At that point I called it a day and covered the Z.

This morning was the real smiler. We had to go into town for the carne for tomorrow and some salad makings, ie, two stops. It was so nice to have a bottom-end back. Before it had gotten to be a challenge at stoplights or stop signs to rollaway smoothly. By my book it was requiring too much slipping of the clutch and too many revs. Now it takes almost no revs and little if any slipping of the clutch. Actually managed to chirp the tires a few times as I'm relearning how to leave a standstill. In terms of acceleration: it's like going from an M44 back to the M52. Before below 3500 revs there was not much, if one was in a gear, running below 4k and wanted to accelerate, one had to drop it a gear - now one just pushes on the loud pedal and off one goes. The wife commented that the Z seemed more lively this morning - was I driving it differently? No I wasn't driving it differently, but it was behaving a whole lot nicer, more bimmer-ish.

So... after this morning's trip there are 50ish miles on the new seals, and my impression is that improvement is still improving. I would guess 80% of the change was present when I fired it last night... and the remaining 20% will buld as the new seals settle in. Bottom line: anyone that has been thinking about doing their VANOS but holding off, not sure if they are up to it, or if it's worth it: DO IT... the job is easy (though many steps), and rewards are very obvious.

x1000 - greg

[328 Power 04]

I'm so glad you had the courage to do it. It's really not that bad of a job. Thumbs up.

So if you had to do this job again... it would probably take about half the time?

[gmushial]

I'm so glad you had the courage to do it. It's really not that bad of a job. Thumbs up.

So if you had to do this job again... it would probably take about half the time?

Actually first let me say thanks to you and the rest that nudged me toward actually getting it done - many thanks and much appreciated!

W/re time savings: I'm not sure one could cut it in half (at least not me) - there's still a lot of things that need to be taken off and put back on.... but I'm sure there are some time savings to be had simply having been there and done that (and not dicking around with the HF tools, or getting dicked around by them ).

Next the RSFB and a clutch job... expect the RSFB to be more like the guibo: fewer, but bigger heavier fastener'd parts; and likewise the clutch.
and after they're done... I guess I'll have to buy another Z, so I'll have something to work on. [actually the wife is starting to push harder for me to find a '01 or '02 Montreal Blue w/ beige interior 3.0 + auto for her... I think after the VANOS she really has become convinced that we can own these fun cars w/o going broke to mechanics - her fear, in that most other cars have been that way: in fact probably part of her working definition of a car: something that one pays way too much for up front, and continues to pay too much to keep running... the Z has been an eyeopener for her.]

Oh, and that's something that I didn't mention above: the VANOS job is either another example of bimmers being engineered to workonable, or the VANOS is the high point of such - we've owned American iron, brand T, brand H, brand V and never does she remember me at dinner that night praising the engineers that designed them and thought about the mechanics that would have to work on them, yet that seems/has become the norm with the Z . [especially with the brand Hs and somewhat the brand T's the conversation has typically been about finding a cliff to launch them off and leave as trash at the bottom, or turning the designers into goat food, or targets for target practice etc etc.]

to all: the best - greg

[ZGator]

thanks for the nice write up - I was thinking about you doing the job, and will definitely try to get this done soon. I work real deliberate and plan to enjoy this one - I did get a good torque wrench- dial type with memory that should work well at that level, I have found that the low ends on torque wrenches can be way off in the past.. I think I have all the parts, gaskets, seals, plan to put it up on ramps and have had it - I hope that it helps with the low end rpm torque / bog under 3500 -4k

[gmushial]

thanks for the nice write up - I was thinking about you doing the job, and will definitely try to get this done soon. I work real deliberate and plan to enjoy this one - I did get a good torque wrench- dial type with memory that should work well at that level, I have found that the low ends on torque wrenches can be way off in the past.. I think I have all the parts, gaskets, seals, plan to put it up on ramps and have had it - I hope that it helps with the low end rpm torque / bog under 3500 -4k

It's not a hard job, just a long one. Where maybe the most difficult part is putting the valve cover back on and getting the wires routed correctly, or, maybe compressing the spring in the exhaust VANOS cylinder to get the bolts started, ie, not rocket science and not really difficult. It's just a lot of steps.

Putting it up on ramps would be a help. I didn't and found that by the end of the day my lower back was feeling it - can't spend that many hours bent over and not pay for it.

W/re torque wrenches - a nice one that one can trust is always sweet. I'm looking for one of my old school beam type torque wrench from the 60s/70s - they always worked, never needed batteries etc. But from this experience: no torque wrench is even better than a bad one, painfully.

W/re parts: the Beisan list of parts (in their procedure writeup) was super complete - you might use it as a check list as to what you need and don't. I was grateful that they suggested having the extra VANOS-piston to cam nose bolts - at $.45 per they cost almost nothing, yet given what happend, I could have been w/o a car for most of a week (waiting for the brown truck to show up), for not having them (they're lefthand threaded, metric and Torex, ie, I couldn't go to my LFAPS and buy one).

W/re the end result: it is sooooo sweet - it's like having a new car all over again. It really, at least in my case where there was ZERO sealing taking place in the VANOS cylinders, makes that much of a difference. ie, all that nice long torque curve that we've all come to love and expect, wasn't there - it was like driving a race motor from the 60s or 70s that didn't "come on" until 4500-5000 rpm. Now as I mentioned, since I was trained to make use of what I had, the first couple starts from a stop sign/light, I ended up chirping the rear tires, ie, I was having to get that far into the gas pedal to launch. Also, not having the idle hiccups anymore is seriously nice - before just sitting one would have the revs drop from 750 to almost stalling, only to have the computer catch it and do something about it - something I'd expect from a Yugo, not a bimmer - and something that left one wondering if it was going to leave them stranded beside the road. Now it idles just dead flat smooth.

I hope you're VANOS seals aren't as toasted as mine were - makes for an unfun car to own/drive... but on the otherhand, the before vs after is so profound that it'll have you grinning from ear to ear.

good luck, and the best to ya - greg

------------------

Just an aside-thought: do people with automatics in their Zs notice the lack of bottom-end as much as those with 5 speeds (w/re toasted VANOS seals)? What engendered this thought is: there is a lady in town with 202k+ miles on her Z and I've got to believe her VANOS seals are toast... but how would these people know it, maybe other than the idle speed bobble? Since leaving a stopsign or light (for them) is simply a case of planting the right foot... and if it doesn't leave fast enough, plant the foot deeper - not like the manual tranny types where it's getting enough revs but not too much and slipping the clutch etc. Just a thought - or what will have to pass as one.

greg

-------------------------------------

A couple artsy VANOS rebuild pictures

"Golden VANOS" ... AMSoil has been here


"missing VANOS" (and, yes we do live at the end of a gravel/dirt road)


"exploded VANOS" (new seals sized, ready to go back together)

[ZGator]

Wow it's that much better! I think I am going to have to get this done even sooner - I am quite sure I ordered that extra bolt as well.. Thanks for the tip on the spring.

Sure looks new with your mileage! I will be so embarrassed if mine is not close to that.. I have used BMW Castrol 5w30 and Mobil 5w30/ 0w40 and always change it once a year - longest it went was with first oil change at 14k when I twisted the dealers arm to do the first one..

[spacecowboy]

You should always spend more on a good in/lb. torque wrench than any other kind. If it's not accurate, the chance of stripping or snapping a fastener is much higher than a medium or high torque fastener.

[Blacklane]

In general, when working on the aluminum head, M6 bolts get 10 Nm, M8 bolts get 22 Nm, and M10 bolts get 47 Nm. That's not very much. It's quite surprising when you feel how little force 10 Nm is. A single stripped hole will probably pay for a good torque wrench.

Actually, a good investment might be a digital torque adapter such as the AC Delco ARM 602-3. It's good for 4-80 Nm and costs about $50 US.

[dkindig]

A single stripped hole will probably pay for a good torque wrench.

+1000

Truer words have never been spoken. After you factor in the cost of drilling out the remainder of the fastener (if broken off), the cost and shipping time of getting good steel threadserts (I don't use heli-coils), and the total time for the repair, a quality torque wrench is a bargain...

And Greg, good job on using your senses with the bolts. I have wrenched for enough years that I can tell when a fastener is getting a proper stretch. This takes PAYING ATTENTION, and you did a great job with that. Kudos to you for feeling that, backing off, and regrouping. Light torque values are the hardest. You saved yourself a lot of aggravation.

[gmushial]

I had promised to post an update as to fuel mileage improvement after rebuilding the VANOS. Though to tell the truth: even if there had been no mileage improvement, simply the improvement in driving fun would have justified the rebuild - having the bottom end torque back is that sweet. But now almost 5k miles on the rebuild and having collected the gas receipts, the mileage improvement is on the order of 8%. Previously the best two tanks of gas had been 27.9 and 28.1 mpg. On this trip, back over I-70 (to KSU and back), there were three tanks over 30mph: 30.1, 30.2 and 30.2. These number were using 87 octane gas, mostly Shell, but some whatever was cheapest or available. I don't have strong data to back it up, but using 89 seems to add another mpg on top of these numbers, but generally being shocked by gas prices I feed the Z 87. I'm expecting to make this same trip over Thanksgiving weekend, when I expect (hope) the temps will be cooler. It'll be interesting to see what effect that has on the mileage. One other data point: the 100mph blast across Nevada on US-50 didn't improve vs last June: still 26mpg - which I'm thinking is an effect of finally getting high enough in the revs that the working vs non-working VANOS has less effect (4200rpm vs 3200). Additionally, these numbers are a combination of: top down, top up, A/C on... tended to drive in the morning and after dark in the evenings with the top down; when I'd had more than enough sun for the day, with the top up and windows down; and finally midday top up, windows up and A/C on. ... now today I'll be happy for a 20 mile day into town to restock the refrig, and reflect on doing 4 900 mile days out of the last 6, but not add another one.

[Telecomtodd]

That engine is incredibly clean. Which Amsoil did you use???

My single VANOS is getting done Tuesday along with the new suspension parts. I ain't doin' it, hells no. Helps having a Master Technician around who needs/wants business, and a dummy with cash who needs his professional help, LOL.

[gmushial]

That engine is incredibly clean. Which Amsoil did you use???

My single VANOS is getting done Tuesday along with the new suspension parts. I ain't doin' it, hells no. Helps having a Master Technician around who needs/wants business, and a dummy with cash who needs his professional help, LOL.

Todd - I have to agree with you w/re the cleanliness of the insides: I was fully expecting to see at least some grunge, or at least a little (at the time of the VANOS rebuild we're talking about a motor with 147k miles on it)... but none was to be found. W/re the AMSoil: "European Car Formula Synthetic 5W-30 Motor Oil (AEL)"... and this is the motor that went 11k miles and 12 months on the oil change leading up to the VANOS rebuild; and where Blackstone came back and said that there was still 20% of the oil's life left. ... life is full of surprises, I especially like it when they're pleasant surprises. Hope you enjoy your rebuilt VANOS as much as I have enjoyed mine.