U just brought back a REAL long thread bro ;)
U just brought back a REAL long thread bro ;)
Sorry folks, I did not mean to step on a 'stringy' hornet's nest...just need to figure out what went wrong with my M52.
Facts are: Car was running fine with the check engine light on for few days until it was parked outside in 15 degree weather for a day or two. It no longer starts. It turns over...battery is fine. Jumped it just to make sure...no start. There must be a spark as the engine (one or two cyliners) attempt to engage...only to follow by dead cranking.
I have read the vanos issue and understand that it may infact be that or a cam shaft sensor. However, in the interest of DYI, and cheapest fix first, I ask the forum for thoughts regarding the following:
Suspecting a fuel supply problem first. I plan to access the fuel pump and make sure that it is getting power. Pressure test later. How the heck to you remove the seat to get to the fuel pump in a 1997 E39?
Secondly, there seems to be some success in disconnecting the battery leads and resetting the electrical system by grounding out the harness. By doing so, re-calebrating all sensors.
If no other easy test...I will haul to garage for diagnostics.
Seems really odd that a frigid night would freeze a vanos or sensor.
I know you guys dont want to hear about the double vanos problem, but i too have a 2000 528it has all the same issues as everybody else does , I also have had to have the rear bushings the ones that connect the rear cradle to the car replaced also my car has 63000 miles and no warranty. bushings are going to run around $900.00 installed....... i contacted BMW also, got an email that was so full of [Oops!]! Iam also done with BMW,s i have three that are going bye bye, tired of the xpensive repair bills for things that should have lasted longer than they did......iam also looking at an Acura TL .....
You really should start a new post for your questions and not attach them to this thread. Also your problem is almost surely not vanos related.
You have a check engine light. That means you have a stored fault code. The code will very likely point you to the problem which is causing your car not to start. Get an OBDII code reader and read the code(s)!
Your situation is often caused be a faulty CPS (camshaft position sensor). There is usually a fault code associated with this problem. So read the code and see if it’s the CPS. This is a simple repair. You might even find that disconnecting the CPS electrical connector will allow you to start the car. The DME (engine computer) might ignore the CPS and default to the Crankshaft position sensor.
If you would like to discuss this further you can write me privately or you can create a new post/thread on the forum where many knowledgeable members will be happy to assist you.
Best of luck.
528i 5sp 06/00
Yes I too am continuing this thread, that in and of itself is a testament that BMW should post some response to the two guys that did all the research to uncover this issue.
Here is my thought\question...
I am encountering this same Vanos problem and error. I have a Peak Research scanner which is confirming that the exhaust VANOS is mechanically stuck. With all the research you have done is it possible that with the Oil change intervals suggested by BMW and the oil change indicator lights... (12-15k miles between changes??huh?) could result in engine sludge build up causing the Vanos to get stuck? Given it requires high oil pressure to advance or retard timing?
Is it possible to clean and replace or would the rings still be the true root cause of the problem?
Purchased car in 2004 with 19k miles on it. Now has 83k the car has been flawless yet I have had this cold idle problem the first winter I owned the car and each winter since then. Only as of late have I noticed a significant drop in gas mileage from avg of 30-32 to avg of about 26-27. Not a lot but enough to notice the engine's efficiency is changing.
Being a fist time BMW owner I stuck to the suggested oil change intervals up until about 65k when I did my first oil change myself. Why I did not do it sooner with the convenient oil filter placement is beyond me. Always serviced my own vehicles. I guess since it was a BMW it intimidatd me a bit. Anyway, I could not believe the sludge on the oil filler cap. Noticable inside the valve cover too as far as the eye could see with a snake light. Given the car has been flawless and tight on cash is there any cause for concern per delaying the necessary VANOS replacement to bring the car back to tip top shape? Since the problem appears to have been here for two years I take it that it is not harming much but poor performance? I also guess I have never drive a true smooth running BMW :-) I always noticed the variation in rpm when ripping through the gears at WOT. I don't beat on the car but every once in a while you gotta let em breath.
Here are my results from 10/26/05 on 1999 528ia (77,990 miles).
California test, performed on dyno, using SteveW's form (Thanks).
15 mph, 1810 RPM
%CO2= 14.8, %O2=0.0
HC(PPM): max=51, average=9, amount measured=3.0
CO(%): max= .48, average=.02. amount measured=0.0
NO(PPM): Max= 419, average=57, amount measured=6.0
25 mph, 1772 RPM
%CO2= 14.9, %O2=0.0
HC(PPM): max=35, average=7, amount measured=1.0
CO(%): max= .46, average=.03. amount measured=0.0
NO(PPM): Max= 706, average=50, amount measured=4.0
Thanks for the support Brian. I try to keep an eye on this thread in case someone posts.
What code are you reading on the Peake and for what table? We haven’t had others report a code. Do you also have an associated engine light?
What car and year do you have?
I bought my car used and found oil sludge on the inside of the valve cover, but the vanos had no sludge deposits. I doubt this is your problem. I’m not aware of a single M52TU engine car that has not encountered the vanos problem. You would be unique if you didn’t have the problem. The problem is the seals.
So far there doesn’t seem to be an indication that components are failing due to the malfunction of the vanos. So you can just hold off. We are working on acquiring an alternate seals solution. I suspect we’ll have something in the next couple of months. This will be much cheaper than purchasing a new vanos and should have a much improved functional lifespan. My new vanos has failed and I’m now experiencing the idle problem again. It’s been less than 2 years since I replaced it.
Your low gas mileage is likely influenced more by other issues than the vanos. I suggest you replace both pre-cat O2 sensors. They’re rated for 100k miles, but we’ve noticed they start deteriorating by 80k miles. You can clean your MAF sensor but be very careful. Spray it with MAF or Electric Contact cleaner, and let it thoroughly dry overnight before re-plugging. You might have a vacuum leak. The CVV and its associated hoses are often the culprit. They will crack and leak starting ~80k.
528i 5sp 06/00
I would like to test my 528i out by disconnecting the intake solenoid electrical connector but since new to BMW's a bit hesitant.
I see two wires leading into an oval plastic piece which is part of or goes into a square piece on the solenoid. There seems to be a metal retaining clip. How does one remove this connection?
It looks like you pry the metal clip towards the engine (left facing engine) but as always there are little tabs in the sqaure plastic piece that may break off.
lost the clip trying to put back on Doh! Anyone have a part number?
I'm in shock at the number of postings regarding this issue. On my own 2000 528sport, I had a rough idle (seemed like the car was going to cut off) and took it back several times to the dealer. They couldn't figure out what it was (no faults). The last time it did it and they replaced the Vanos. Fortunately the car was still under warranty, but just barely. Now it's a year later and it's doing the same thing again... this time the car dies - IN THE MIDDLE OF DRIVING. Obviously this is extremely dangerous. I'm floored and fully torqued at the thought - and obvious fact this is an ongoing issue that BMW is no doubt aware of.
At this point I doubt they'd do a recall of any type. Out of warranty owners are left to fend for themselves on this flawed design issue... For BMW this is uncool.
Yes please keep us all informed about these new seals, I would hate to invest in a new VANOS only to have it go bad in a year.
How long will it take to test these new seals to determine it is a fix?
My 99 528iT has exhibited exactly these symptoms during the last two winters since I bought it: "It occurs on cold weather cold engine starts and takes the form of repeated engine attempted stalls and possibly a complete engine stall. The engine rpms drop dramatically and then recovers. This then repeats after a few seconds of steady idle. "
I discussed it with my indy mechanic (who has heard of the VANOS problem) and during my last service he reprogrammed the DME with the latest update. The problem is gone - I have a steady, smooth idle from cold start with not a trace of the stumble and stall *and* I have at least 10% better gas mileage in city, from 18.4 to over 20.
I don't know enough about the DME updates to tell you what I have before and what was reprogrammed. I just know it worked.
99 528iT Individual Mojavebraun
my 2000 328 has done this from 70k miles to 116k. it gets worse the more miles you have one it. now if its a cold start below 50, it will do the rpm flutter, ~10 times in ~5 minutes (until warm), stalling maybe once or twice. I've noticed if the car is parked "uphill" it will do it more. thougths? anyone have the uphill symptoms? it seems that i notice it does it more freq right after an oil change...
I have the same problem on my 2000 528i and i may consider having the dealer give it a shot. If you don't mind me asking, how much was the DME update?
Thanks for the update. Good info to know. Another person had reported a similar situation but it wasn’t clear. Your experience seems definitive.
I’m not surprised BMW updated the code. As we had explained from our first letter to BMW we expected the idle problem was created by the DME. The DME software is not reacting well to the vanos failure and creating the idle symptoms. As I’ve explained in other posts, I expect that BMW knew of the vanos failure during testing of the M52TU engine (99-00). Instead of addressing the vanos hardware problem they elected to modify the DME software so that it acts “normally” to the vanos failure. As we know the DME shows no indication of vanos failure and does not set OBDII fault codes. The vanos failure was likely encountered in mid testing when the engines had 40k+ miles on them. Software mods were likely made to most of the software but they missed a unique spot in the code where the vanos is used in an unusual application. This is the cold weather cold start situation when the vanos is used to help heat up the cats faster. Subsequent to manufacturing the M52TU, BMW likely became aware of the “missed” location in the software where the code was not “messaged”. By the release of the M54 engine BMW had this section modified likely like the rest of the software to act “normally” to the vanos failure. So it’s no surprise that they would go back to the M52TU engine code base and update it with the same patch.
Instead of addressing the vanos hardware failure BMW elected to incorporate “software workarounds” to smooth over the problem and hide its existence.
I do not have the facts to prove that BMW found the problem during M5TU testing and modified the software to act “normally” to the failure, but all indications seem to point to this.
With regard to improved gas consumption with the updated M52TU code base, BMW might have been able to modify the software to better function under the vanos failure and achieve better gas consumption.
The double vanos provides many great benefits: improved, power, torque, gas consumption, emissions, etc. A software fix might be able to keep the engine from faltering and throwing codes, but it can’t make the vanos overcome its hardware failure and perform properly. A software fix can not provide the improvement in power, torque, gas consumption, that a properly functioning vanos provides.
Here’s something an owner recently wrote me after replacing his vanos, “Wanted to follow up and report that "yes" the car does feel quite a bit faster. Definitely more of a "pull" than before.”
The true solution to this problem is a hardware fix to the vanos. We have sincerely attempted to work with BMW to address this matter. But after they strung us along for almost a year they finally came out with a clear position: “No further development will be done”, ie the problem will not be addressed. This has unfortunately been their consistent position since the very beginning when they discovered the problem.
BMW is continuing to sell replacement vanoses with the same failing piston seals. We purchased a new vanos and had the piston inner O-rings tested for material makeup. We found that they are made of Buna. Buna is a very common material used in O-rings. Unfortunately it is limited in temperature and chemical resistance characteristics. Thus we are not surprised that it has faired so badly in the vanos. Upon inspection we have found the Buna O-rings to flatten at their top and bottom surfaces, shrink in size, and plasticize thus loosing their elasticity. The outcome of this is the loss of support for the Teflon outer seals and thus the loss of the Teflon seals’ ability to sustain a seal with the vanos cylinder walls. This all causes failure of the vanos function.
I was hoping that the vanos failure would show up in emissions testing but for whatever reasons, and this can be speculated upon, this has not been the case. Thus I don’t believe we can convince the government to force BMW to address the problem.
Therefore as a last resort we are going down the path of reverse engineering the design and producing better seals. We are very fortunate to have a seals expert working on this effort for us, Tony540. We have talked to many seals experts and manufacturers and they have consistently recommended that we use Viton as an O-ring material for this application. Viton has much better temperature and chemical resistance characteristics than Buna. A main complication to replacing the O-ring is the Teflon outer seals. These will be damaged when removed from the piston seals grove, thus new ones will be needed. The vanos Teflon seals are unique in dimension and thus need to be custom manufactured. Teflon seals also require special tools for installation. They can not simply be stretched and mounted like O-rings. Thus we are working with a seals company to manufacture the Teflon seals and Viton O-rings. We will also be working with a company to manufacture installation tools especially made for the vanos piston and Teflon seals.
We are waiting on a first small batch of the seals, which we’ll be receiving very shortly. We (Tony540) will install them with custom built tools and test for proper fitment. We (Tony540) have made very careful measurements of the vanos and seals and have worked closely with our seals manufacturer to ensure proper dimensions for the seals they’ll be manufacturing. Once the fitment is verified, I’ll be installing them on my car. I’ll be performing before and after performance tests. If all goes well I suspect I’ll look for a few owners to perform the repair on their cars and providing feedback. Again if all goes well, we’ll be ordering the seals and tools in larger number so we can begin to distribute them to others. The performance tests of the car with the new seals will be an indication of the function of the vanos in “real time”. I might have to purchase one more new vanos from BMW and perform the performance testing on it just to prove the redesigned seals provide the same performance as a new BMW vanos. I plan on finding owners that will allow for the replacement of their seals after a specified period. This will allow for inspection of seals at set periods of miles. I’m currently thinking of 20, 40, 60, 80, and 100k mile inspections.
I’m putting together a thorough writeup on the complete repair procedure. I’m also creating a website to facilitate the purchase of the seals/tools and access to the repair writeup and other relevant information. I’m still working out the costs of the items but am trying my best to keep the costs down. The cost of the seals and tools will be a fraction of the cost of a new BMW vanos.
I hope much of this will be ironed out in the next three months. Much of this effort has been slow coming in this past year, but things are moving faster these days. I’m now practically working full time on this effort, and Tony540 has been extremely generous with his time and effort.
Well, I’ve gone on a bit. I surely don’t mean all this as a response to Stephen. I’m just trying to provide insight to others reading this post and give an update on our efforts to address this problem.
Stephen, thank you for the post.
528i 5sp 06/00
Given all the insight we have on this situation I think it won’t take long, maybe 3 months. There’s also a limit to the testing we can practically perform.
We have measured the vanos and seals and have a good understanding of the BMW design. We have spoken with several seals experts and companies. Tony540 and our seals manufacturer application engineer have worked through the specifics on several occasions. Tony540 will be installing and inspecting the seals function. We have consulted with many experts and have received consistent feedback on the materials we should use for the seals. I’ll be performing performance testing on several seal sets. I’ve purchased an Autoenginuity scanner module and will use it for dyno like performance testing. My current seals are two years old and have started failing. I have a vanos that was recently removed from a 99 328i which was showing full vanos failure symptoms. Of course I’ll have the new seals solution we’re manufacturing. I might also buy a new vanos just to have its performance tested for a landmark reference. All this can be done in a fairly short period of time. I’m planning on having 5 cars with the new seals that we’ll inspect at set mile markers, 20, 40, 60, 80, and 100k miles. Of course the mile duration testing will take a long time to occur. We just don’t have access to facilities that BMW has. They can likely run these engines on test beds 24h/day. It’s not practical for us to dedicate cars for driving continuously just to see how the seals hold up.
We are doing our best due diligence to have a seals solution that will sustain well in the vanos engine environment. We have proved that BMW is using Buna O-rings and that’s why the O-rings are failing. We will be manufacturing Viton O-rings that are proven to have significantly improved characteristics that work well in the engine environment.
Our timeframe is more constrained by manufacturing timelines. We first need to verify prototypes of the seals and tools. Then we’ll need to place large volume orders so the single item costs can be reduced for the end user. Manufacturing timeframes are in the 2 month rage.
My other post just above also provides some insight.
528i 5sp 06/00
In the interest of keeping all of this GREAT info in one place, here's the link to my similar experience. Since then I've had about dozen mid 20F cold starts without any symptoms. I just hope the seals don't deteriorate to the point where the symptoms reappear or the warm idle problems reported by some begin.
I would not have thought that an Indy would have access to DME updates. I hope your fix is real and not adaptation related. Keep us posted.
BMW CCA 69606
Waht was the cost of the dme update.
I had the DME update done along with some other work; the line item on the bill is $150. The indy mechanic told me that he purchased the gear for the DME updates and it was $$megabucks.
I'm off work Monday and will visit and try to get some details on the DME update done, software versions (if that's what they are) etc. to better describe what was done.
Thanks, Rajaie, for the thorough response. I in no way meant my story to contradict any of the Vanos research, I was just relating what is going on with my car. We've had below freezing mornings almost everyday since the update (1/29/07) and I'm having smooth idles every day.
99 528iT Individual Mojavebraun
528i 5sp 06/00