E36 Noisy VANOS

Sorry, I have no clue.

I have seen the valve train - including VANOS - on my car, and if you can stabalize the cams at TDC, replacing the chain and sprockets should be reasonably straight forward. There is a special jig to keep the cams lined up correctly, perhaps your mechanic will loan it to you.

My guess is, that if you can hear the chains they probably must be replaced along with the respective sprockets. I don't know much about the VANOS unit itself, but my recollection is that it hasn't got any adjustable parts, that is the adjustments are all on the ends of the cams themselves not inside the VANOS mechanism.

Yeah, Jeff, thanks for the reply.

I know how the VANOS works too, and I can't for the life of me figure out where this sound would be coming from. It's not really a timing chain sound (I have owned a SAABs that had stretched chains). I should record it somehow and post it somewhere.

If it was just a loose chain, based on my prior experience I'm sure I could cob a fixture together to hold the cams, or as you say borrow one, and get the chain replaced. But my wrench said just the tensioner for the upper chain loop and the VANOS assembly need to be replaced. He also mentioned something about the VANOS's solenoid rattling.

The VANOS assembly is about $300 best price I can find, which of course prompts my research to determine if this is truly needed. I know there is a BMW for just the VANOS solenoid, if that is all I need, and I'd bet it would be substantially less than the whole kahuna.

I googled for a while and came up with a number of folks that said the type of oil used will make the VANOS noisier or quieter. There was even one that particularly mentioned the use of Mobil1 Synthetic 5W30, which happens to be what I'm using at this time. I suppose it is related to the VANOS's use of the oil pressure to actuate the cam advance mechanism. I have also heard that Mobil1 is on the thin side of spec, so maybe there is something to this idea?

I guess I'll continue with my plan to do the oil change first off, and just use dino 15W40 or something and see what that does.

--

-Fred W

I'd be pulling the valve cover to see what's up instead of changing the oil. Well, there is never a bad time to change the oil, but if there is a "real" mechanical issue to deal with, new oil will be nothing more than a mask.

There is the main timing chain and then there is the VANOS chain, or two. There are tensioners for these, and perhaps you have a stuck tensioner. No matter what you have, you need to pull the valve cover at the very least to find it.

No, that's not how VANOS works. The main chain drives the exhaust cam off the crankshaft and the second chain loop connects the two cams toeach other (exhaust and intake).

The VANOS is a electric solenoid that opens and closes a valve which routes oil pressure to an actuator or blocks it. The actuator slides the intake camshaft's sprocket forward and backward along the end of the camshaft, which intead of having a straight splined end or keyway as normal camshafts do, has a worm-gear type spline cut into it. So by sliding the sprocket for and aft, the rotational relationship of the cam to the sprocket can be varied and that's where you get the timing advance.

So there are no "VANOS" chains, just gears, and there are only the two timing chains.

I suppose the upper timing chain could be loose. I really don't think this noise is a chain, but...

...you are probably right about that. I was just wondering what this other chatter online about the "VANOS noise" disappearing after changing the oil is all about.

I had the VANOS replaced on my 95 525i lst March for this problem. I got to play with the old one after it was removed. What I discovered was that the rattle came from the rotational function of the worm gear actuator (it turns with the upper timing chain and intake cam.) It was a bit worn allowing it to rattle at idle. It probably didn't need to be replaced at least from a mechanical standpoint. The idle is quieter now but there is still a bit of valve clatter.

I had the VANOS replaced on my 95 525i lst March for this problem. I got to play with the old one after it was removed. What I discovered was that the rattle came from the rotational function of the worm gear actuator (it turns with the upper timing chain and intake cam.) It was a bit worn allowing it to rattle at idle. It probably didn't need to be replaced at least from a mechanical standpoint. The idle is quieter now but there is still a bit of valve clatter.

Thanks DP,

that is 'zactly what I was looking for. Yes, I can see that being the issue. And it also 'splains why my reputable indy wrench was not very excited about it and did not feel the noise was serious.

I will probably pursue it anyway, maybe just start by disassembling as Jeff suggested, and see if I can see what's what.

Also, before anyone jumps on my description of VANOS, the solenoid actually moves a valve that routes the oil pressure one way or the other (advanced or retarded). It does not just block it.

My indie used to work for the local dealer and said he had replaced maybe three EVER just for the noise. Seems most E34 drivers don't care about it. I would think more E36 guys would want it taken care of though. But in any case, no one I talked to ever heard of one cratering and causing the cam to seize or anything like that. It seems the only flat out failure of them is the solenoid / actuator fails to actuate leaving the car in limp home mode.

Thanks for the clarification. I have only looked at the gears, sprockets, and chains, then recited what I thought I saw from memory. I wasn't too far off, and the best way to see what the problem is is to pull the valve cover and go from there. I remember the VANOS as having chains, but that could easily be the exhaust/intake chain in addition to the "main chain". I clearly remember the slotted holes on the intake sprocket, and a rod that goes to the VANOS thingie.

In any case, thanks for clarifying the description I gave. I hoped that what I said was close enough to allow somebody to look at the actual parts and move along with his repairs.

I haven't heard of this "common" problem either, but I can't argue the point so I just go along.

Excellent photos here of the whole mess...

Thanks again. That's even more reassuring.

Wowsers. Thank-you yet again. I owe you a big one.

I was not aware of those tech articles (at Pelican) and that one is just what the doctor ordered. I think I may be going in and doing a biopsy later today.

Follow-up for anyone following along at home and for the archives. (Usenet seems to get captured for perpetuity all over the place)

I popped off the valve cover on my 325i yesterday and poked around. Both chains appeared perfectly fine and tight as a drum. I exercised the upper chain tensioner by hand (the one my indy wrench recommended replacing) and both the spring tension and oil plunger both seemed to be fine. I continued to poke around by the VANOS and could not find anything that appeared loose or to have too much lash.

I popped off the oil line to the VANOS and then removed the solenoid. You really need to get the oil line out of the way to get a wrench on the solenoid. I exercised that a bit and I pulled out the spring loaded plunger from its bore hole. Everything looked OK, but since they were stained with old motor oil, I decided to clean them both up as best I could before re-assembly.

Put everything back together and immediately did an oil change with Castrol 20W50. According to the chart in the owners manual 20W50 is fine for everything down to well below freezing. I'll re-assess the oil grade when the snow starts flying if it is hard starting then.

In any case, started it up and she is as quiet as she's ever been.

Now granted, I didn't start the engine with the cleaned VANOS solenoid and plunger and the old oil because, well, I had just cleaned them, but I am convinced that the noise was in fact due to the thinness of the

I sure hope the gaskets sealed back up OK because they seemed rather stiff. I bet I'll be back in there replacing those before too long for oozing seals.

I may try using a higher weight synthetic next time and see how that goes. That may work better in low winter temps than the dino juice I have in there now and still keep Mr. VANOS happy.

I saw that in the Owner's Manual this weekend too, and was perplexed by what the chart said. I've seen other charts that said that 10w30 was good to

I have trouble with 20w50 as it is described in the owner's manual. Having said that, it should remain in the motor much longer if only because it is thicker.

I would have lilked you to start the car with the valve cover off and with the VANOS solenoid cleaned, and before the 20w50 went in.

Fred,

Glad to hear you've fixed the Vanos problem, and thanks for posting the solution. While using 20W-50 is probably ok, I'm one of those sticking with the 15W-40 as recommended in the owner's manual for my 97 328. I like these oils, as they (all brands) seem to be diesel rated, and therefore have more anti-wear additives than oil for just gasoline applications.

Another thought that I've had, is you know there are spray jets from the crank bearings to the bottom of the pistons. It seems to me that the oil viscosity would be quite important for obtaining the proper spray pattern for these jets, and possibly other 'fancy' places for distributing oil within the engine. Just a comment for your consideration, now that you've found how the higher viscosity helps the Vanos

Thanks again for posting the effect of the oil change.

Frank

Malt_Hound, > wrote:

You would, would you? Why is that? Do you think my garage needs a good spraying with motor oil? I would have at least put the cover back on before I started it.

I'm very certain that I don't think cleaning the solenoid or plunger did much. But you are correct, I didn't follow good investigative scientific protocol on that experiment. But hey, with a sample of 1 it isn't statistically significant anyway... ;-)

Yeah Frank,

I wouldn't have used the 20W50 except for 2 things:

2) I feel a lot of good juju about Castrol motor oils. Years ago it was all I would put in my Mazda rotary engines as it was one of few that were certified.

4) I didn't know how long (measured in minutes) this stuff would be staying in my crankcase.

Even with all of the above, I don't know how long I'll leave this oil in there. I mean, the thing is, the Castrol Dino oil is so damn cheap you can afford to cahnge it almost every weekend. I mean, damn it's almost cheaper than gasoline...

"yes-sir-ee Mr Gas station attendant. Change the oil, if you please, and, er, Oh... go ahead and check the gas too!"

Well, no I don't want to squiret oil eveywhere.

I was thinking that if the VANOS was installed and connected properly, the oil flow would remain on the top of the motor where it belongs. Racing the motor would spray oil, but an idle or a bit above idle should not cause oil to wet down your garage.