Vanos Help any ideas?
I just have a few technical questions and would like a little advice on my Vanos.
My car: 1995 BMW 325is
Production date: 5/95
Motor: M50 T/U, 2.5l inline six, single Vanos, 5spd tranny
Miles: 140,000 miles
Upgrades to motor and drivetrain:
Pair of S50 cams out of a '95 m3
3.38 Limited Slip Differential
UUC System U catback exhaust
Cosmo Cold Air Intake
Turner Motorsport Conforti Chip (designed for the s50 cam upgrade)
Although not an upgrade from the stock, I replaced my clutch with an OEM spec setup at 140,000 miles.
Some background info:
I've been an auto mechanic at my fathers garage for about 5 years now and sadly most of our business is American cars. Ever since I purchased my first Bimmer I've been addicted. They are so much different than all other cars and I love the whole aspect of the great engineering and performance. Being as I've never worked on much else in reference to cars, the German scene really caught my attention and it became a hobby to work on, drive, and make new friends with the same interests. To date I've owned 3 BMW's. I have my '95 325is, I also have an '82 320iS put away in my garage as well which is currently being restored by my brother and I, and I had a '91 525i which was my spare driver while I worked on my '95, but I sold the 525i this winter to make room in the garage. I work on all my cars myself (other than paint and body work which my brother takes care of for me).
Alright now the whole reason for needing the new Vanos is as follows:
The car is a summer daily driver for myself. I put the car away every winter in my garage at home in which it currently is parked. I had previously installed an aftermarket CAI, cat-back exhaust, and the chip. I was ready for more power and just enjoyed working on my car. So at the beginning of last summer (2008) I decided to purchase the cams and differential out of a '95 m3. I put my '91 525i on the road for a few days while I swapped my cams. Before the swap my car ran perfect and made no sound, I had always heard of the "dreaded Vanos rattle" from friends and forums but never experienced it for myself with my car. All in all the swap went great. I used the cam lock and flywheel pin which I borrowed from a friend. The last step I took was a replaced my previous TMS chip with the upgraded version which Turner sent me to better suit the new cams. I started the engine up and it fired instantly and ran smoothly for about 2-3 minutes and began to gradually grow louder. The sound was a consistent rattle (which later on I basically concluded to be the Vanos unit). Due to the fact that my Vanos never gave me trouble before the swap, that was the last thing that came to mind that could be the noise. Although it wasn't terribly loud it was enough to notice something wasn't right. Right away I decided to pull the valve cover and my first thought was the plastic oil splash guard on the intake cam could maybe be making noise if the duration and lift of the new cams were obviously a little larger but removal of the guard made no difference. Being as the noise wasn't horrible and the car seemed to run well I decided to drive it for a few days and see what became of the noise. Surprisingly the noise almost seemed to go away as the RPM's raised and was only noticeable at an idle (which is yet another reason I would say it is definitely a Vanos issue due to the disappearance of the noise at high idle). Being the procrastinator that I am, I continued to drive the car for about 2 months until I put the car away for the year. Over the 2 months the noise gradually got louder and at idle sounded just like every other M50 with a Vanos noise. I would say it sounds more like an F-350 Diesel truck than a 2-dr German car.
I'm not sure if this is a placebo effect or if this makes sense but:
A week before I swapped the cams, I swapped my old 3.15 non-Lsd for the 3.38 Lsd first. I drove the car and of course the difference was amazing. The gearing was perfect 1st gear pulled extremely hard and even the fact that in 5th gear at 65mph I was running at about 4k Rpms didn't bother me because I didn't really travel on the highway and majority of use was city traffic. On the back roads up in the country near my house the power was amazing and cornering was perfect. I was so excited to put in my cams because I figured if the differential alone made that much difference I couldn't imagine what the cams would do on top of it. After the cam install, despite the noise issue, I never quite thought the performance gained at all. Now this is where my confusion comes in. Now assuming the Vanos is only making noise and not having a actual effect on the performance, would the 3.38 Lsd along with cams have a slightly different effect such as instead of the torque showing through in the lower gears (with just the differential swap), but that the power range would be moved towards the top end of the rpm range with the new cams power curve (with the Diff. and the Cams combined). It seems that with the amount of work and upgrades I've added to my car that the cams would have been the icing on the cake and made a world of difference. But now on the other hand assuming that I should have gained a lot more noticeable power than I actually did if all conditions were right this could possibly be the deciding factor determining that my Vanos is in fact screwing up my cars actual performance (rather than only making noise).
The way I understand the Vanos unit is at low rpm range (at idle) the unit retards timing to make a smooth idle and as you begin to raise the rpms the oil pressure unit on the Vanos pressurizes and slightly kicks the cam one way or another to give you better performance on command without the rocky idle of a car with high performance cams and allows you a more linear power range. Now if I have this idea even slightly accurate, the fact that when I did the cams install I had the Vanos unit off the car and when I removed it of course the unit depressurized and lost some of the oil inside it. So maybe my Vanos was starting to go bad before the swap and the fact that I had it off and put it back on may have been the last straw and finally the problem began to show through. A month after I put the car away I looked around ebay and some forums and found a used Vanos unit that was said to be in good shape. Of course looking into the problem further I found that the problem is so common that even though I purchased this Used Vanos for like $50 I would (if I have to take it all back apart) rather not take the chance of the same thing happening.
So now the car is sitting in my garage and it's starting to get warm out now and I'm gonna have to bite the bullet and tear it apart again. If it's all coming apart I'm not gonna take a chance and put a used Vanos off of ebay and have it turn out to be the same.
Let me know if you have any info that could help me.
I think im gonna go with DrVanos but im not sure if its my vanos or not. thanks