Vanos noise with M3 cam in M50tu

jeff325525 · 11-12-2006, 11:12 AM

I put S50 cams in my 525i with M50tu engine. The engine runs great, but I have one down side, increased VANOS noise at idle. I put a new upper tensioner during the cam install. I compared my cam chains to new chains and they looked pretty good so I left the old ones in. The engine has 137k. At idle the engine sounds much like a diesel. When you are in the car with the windows up it is barely noticeable. The noise goes away about 1200-1500 rpm, and I hear no unusual noises at high rpm or under deceleration from high rpm. I added a custom D'Sylva chip and dynoed the car at 188.3 rwhp which seems about right. My car is 5/94 build so has the early VANOS design with the two flat plates and no spring washer. My questions are:
Has anyone upgraded the early VANOS to the spring and newer plates? Does this reduce the noise?
Will the newer lower tensioner from the S50 help? My engine has the two part lower tensioner. Also I found a video clip on google of a 95 S50 at idle and it sounds exactly like my engine. Before the cam swap my engine was much quieter. I am running Castrol 0W-30 (GC) which prior to the cam swap made the engine quieter than M1 5w-40. I set the VANOS twice and tried it with the new and old upper tensioner. Both times I checked the travel and it was correct.
Thanks in advance. I used the excellent articles to help with the cam install/removal.

Jeff
95 525i
91 525i
97 325is

Wayne 962 · Wayne 962's Garage

Hi there. Are you sure that it's the VANOS unit? The sound you're describing sounds more like stuck lifters (which can happen when you change the cams), than the VANOS unit. Where exactly is the noise coming from?

-Wayne

jeff325525 · 11-12-2006, 06:18 PM

The sound comes from the vanos unit area, not from the lifters. All my lifters turned freely. It almost sounds like the Vanos unit is hitting the valve cover. I disassembled once and re-assembled to make sure it was together right, and put the new upper tensioner the second time. The new tensioner made little if any change in the noise. Go to
http://video.google.pl/videoplay?docid=-1009005054806964026
this is exactly what my engine sounds like.

Thanks,
Jeff

Wayne 962 · Wayne 962's Garage

I listened to your engine there, and you're right - it's not a lifter, and it does not sound normal.

It does sound like something is not quite right with the gears on the VANOS unit, and when you rev it up, it seems to mesh (work) and then go away. But you already know this.

Okay, if I were troubleshooting this on my car, I would remove the valve cover, pull the DME relay and turn the engine over with the starter, while watching the VANOS unit carefully. Also inspect the inside of the valve cover to make sure nothing is hitting. Also review the VANOS install procedure and cam timing here:

http://www.pelicanparts.com/bmw/techarticles/E36-Camshaft-Timing/E36-Camshaft-Timing.htm

This noise is definitely not normal, and there is something seriously wrong that should be fixed before you drive it any more...

-Wayne

jeff325525 · 11-13-2006, 05:43 AM

The video clip is not my engine, it is an S50 that sounds just like mine. I already checked under the valve cover, nothing is hitting. I am wondering if I convert to the later style vanos with spring if that might help. Has anyone ever updated the older vanos? Does anyone know why BMW updated the vanos with spring. I'm thinking it may have been to reduce noise. If I had this to do over I would have bought a new helical gear for the end of the cam, that would tighten the fit. I don't believe there is anthing seriously wrong as the engine runs strong and the noise goes away with some rpm. Wayne, do you agree the lower cam chain tensioner probably won't help?

Thanks,
Jeff

yelcab1 · 12-05-2006, 06:54 PM

Jeff

Did you ever figure out what is wrong?

jeff325525 · 12-06-2006, 05:32 PM

I ordered the spring plate, studs, and thin and thick plates for the later VANOS unit, and plan to install them this weekend. I will post the results after I get them in. I will shoot some video before and after.

Jeff
95 525i

slim17265 · 12-11-2006, 04:16 AM

I have heard of this on other boards...0 weight oil can do this, If Iremember they went to 15W40 and the noise went away..here is a link(with 136000 miles I would not be using 0 weight anyway)
http://forums.bimmerforums.com/forum/showthread.php?t=265292

jeff325525 · 12-11-2006, 09:36 AM

My engine is now very quiet, sounds like new. Here are the parts I put in:
11361403823 disc 4mm
11361403822 disc 2mm
11361403550 spring
11361403824 studs (3)

11311722651 guide rail

I removed the existing studs and disc. I assembled the new parts on the intake cam and fit the VANOS. I followed the factory procedure from the TIS. The intake cam sprocket is now much tighter, you need the tool to turn the sprocket to engage the VANOS gear. I also put a new guide rail, I had changed the upper tensioner last time I had it apart. I checked the VANOS travel, it was about 10mm. BMW does not specify the maximum only a minimum of 8.5mm. Last time I had a number of 9mm. Vanos travel is more difficult to check with the spring, since the sprocket does not readily return unless you rotate the engine. The engine is now very quiet at idle and feels smoother at higher rpm as well.

I compared my upper chain to a new chain, and found them pretty much the same, so put the old one back in. I wanted to minimize changes, so I could see if the updated VANOS springs would help. The ETK for my VIN lists these parts for 9/92 to 3/95. I believe these parts were put in new engines from 4/95. My car is 5/94 build.

With regards to the comment about 0w-30 oil, I am running Castrol "GC" which nearly has the viscosity of a 40w oil at 100C. I have found this oil to really quiet an older engine compared to other synthetics. It has its own forum on www.bobistheoilguy.com. I think it is a very good oil.

The parts without guide rail were around $60 with the BMWCCA discount. If you are putting S50 cams in, I think you need them.

Jeff
95 525i

M325 · 04-20-2007, 05:10 AM

All,

I had the same experience as Jeff - after install of M3 cams in a 94 325, had loud vanos exactly as in the video. I also installed the 95 thrust washer retrofit (I also replaced the intake cam gear while I was there), and the car is quiet as new, with smoother power delivery.

The instructions here on PP were sufficient and essential to completing the work. My local independent quoted $1K, just to open it up and retime cams/install thrust washer kit. Cost of all parts (intake cam gear, thrust washers, upper and lower chain tensioners) was about $200.

russde · 06-12-2007, 01:04 PM

Ah Jeff, many thanks (I hope),
I have been pulling my hair out for two days trying to figure this out, the sound clip was EXACTLY like my car sounds. I have reset the timing 3 times now convinced I must have done something wrong.
I have the parts ordered and will see them in about two days. Good luck to me, and thanks to you for being the guinea pig!
Cheers,
Russ

russde · 06-15-2007, 04:23 AM

...and failure.
I put in the updated spring and thrust plates last night. The horrible VANOS noise at idle was gone and I thought I had it licked.
However, the car doesn't want to idle. At first I thought it was my new D'Sylva chip for the s50 cams so I put my Dinan chip back in, with the same results. I can really work with the throttle and finally get the car to idle at throttle but with any release of the throttle the car refuses to idle, one bounce and then it dies. Will start right back up.
I decided to try to drive the car anyway to see if the DME just needed some 'learning' time. Before the end of the block I had the RPM's at 2k and instantly was rewarded with a horrible VANOS rattle. I turned around and went back, keeping the RPM's below 2k.
Oh well, at least thus far I've learned to R & R the valve and VANOS covers with expertise.
Any suggestions welcome,
Russ

Jeron · Jeron's Garage

How carefully did you set the timing?

russde · 06-16-2007, 07:15 AM

Quote:

Originally posted by Jeron
How carefully did you set the timing?

Very. I didn't use the cam lock the first time, but when I disassembled the cams were spot on. The second time I did use the lock and honestly can't tell the difference, nowhere in the install do you do anything that would move the cams.
I disassembled again last night. Can't see anything physically wrong, at TDC the cams are perfectly in line with the head and parallel to each other.
I think I'm going to re-install the original cams unless I can find a competent machine shop familiar with BMW to check the M3 cams as I'm really leaning towards them being the problem.
wish me luck,
Russ

Jeron · Jeron's Garage

Not moving the cams is important but setting the timing in relation to the VANOS movement is more difficult. I'll know more in a few days, but you have move the VANOS to the extreme edge of its travel. The Bentley and the 101-projects book seem to cover it pretty well.

russde · 06-17-2007, 01:54 PM

Well, it turned out to be human error. Mine.
I disassembled everything yesterday and started to reassemble last night, this time following every single step in the Pelican diy instead of relying on memory.
I had completely forgotten step three in the write up. Offsetting the intake cam primary chain sprocket is essential. I realized that I had neglected to do this on the last install and decided to also clean the ICV to hopefully eliminate a fluctuating idle from before this whole fiasco.
Got everything buttoned back up this afternoon and all seems good so far. I am waiting for the car to cool down now so that I can ensure the cooling system is bled, then I'll take it for a shakedown run.
Cheers,