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HELP!! 645 increased emissions- car wont start?!?!

8K views 50 replies 14 participants last post by  maybellineo 
#1 ·
Hey Bimmerfest, First post, and I'm in a pretty odd situation.

History: I just did a road trip from Delaware to Cali in my 2004 645 (45k miles). Now, before the trip, my car would occasionally stutter before it started, but presented no issue after. Also, the dynamic drive malfunction would appear and disappear randomly.

Fast forward: After about 2500 miles, filling up with only 91, 92 and 93 gas, my "gas cap needs to be tightened" light would appear, but always disappear. Then, while starting my car after a fill up, the car stuttered again, then boom- increased emissions- service engine soon light. At this point I'm in New Mexico heading toward Sacramento.

FF again: While driving through Cali, my window lights would randomly flicker on and off. And when this happened, almost on cue, the dynamic drive malfunction would appear. Increased emissions light never disappeared. The final straw? In Fresno, I pulled over because my idrive screen began to flicker. When I tried to start the car, it would attempt a quick crank, idrive would flicker out of control, then nothing. Eventually the battery died. I had to get it towed to the dealership (terrible look) Thursday, and they can't look at it til Monday. I'm very worried- after reading forums, I would only suspect an O2 sensor, thermostat, coil, and/or power steering fluid to be the issue. However, I'm now in Sacramento waiting to hear the dealer's "professional opinion". Very worried about overpriced repairs. What do you guys think the problem is?? Please help. What should I do?
 
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#6 ·
I'm a bmw tech, I may be able to help. It sounds like your alternator failed. The dealer should pull faults to verify this. Your battery is probably damaged due to the alternator failing. Don't leave the dealer without them checking the alternator! You don't wanna get stuck again further down the road.
 
#8 ·
I'm a bmw tech, I may be able to help.
I just got back from the dealership. New battery- everything looked fine. Diagnostic came clean after replacement. Nothing with the alternator showed(made sure, i watches the process). 3 hours driving north, I started my car, and another hesitation start smh. 20 minutes in the drive, I switched lanes, and as soon as my car ran over the little "lane lights", my cd skipped, dynamic drive malfunction came up, and my window lights flickered once. What the hell is going on??
 
#11 · (Edited)
Given that so many items skipped would suggest a common power point/ ground. Given the battery has been changed means they will have tightened those bolts so go to the ground to the battery, which is under the mat and check, then go to the main fuse/relay distribution points and check the main connectors for a starter!!!!! should not take long, press in all the fuses and relays in case one is loose!!!!
 
#12 ·
It still sounds like an alternator. This exact issue is frequently misdiagnosed because these alternators usually fail once they get hot enough. If they are checked once its cooled down, it will pass all the tests. Your dealer should have checked for a specific set of faults.... Like BSD communication error to the alternator, over/under voltage at the ARS and EGS vs RPM (these 2 are the most sensitive to voltage issues).
 
#13 ·
I see. Sacramento is about an hour away from me. Perhaps if I set the diagnostic up there upon arrival, I can try to capture this possibility.. will update accordingly.

@645/333 All my fuses are snug, didnt feel anything loose.
 
#14 ·
It's starting like you could have an alternator or regulator starting to fail. If you took it to a BMW dealership, they should have run the diagnostics regardless. It is possible that the battery was not charged, prior to installation. If you have a multimeter, check the voltage of the battery while the car is off, then on. If the alternator is charging, you should see a difference.

Good Luck!
 
#15 ·
Here's an interesting twist. I remember reading many instances where the power steering fluid caused the dynamic drive error. This morning, I started my car and immediately an error came up saying "loss of power steering fluid". I am taking my car to the dealership today to top it off, and get a diagnostic while the car is warm. Is it possible that this was the culprit the whole time? Causing the flickering light as well?
 
#17 ·
Electrical problems can drive these cars crazy! The diagnostics should help. While they are running your diagnostics, have them to make sure your battery was registered.

Good Luck!
Saw your comment after the visit. Don't hate me for this haha, but I skipped the diagnostic. They wanted $175 for it. I just wanted to see how the car would operate after adding fluid. My steering fluid was definitely low, so they topped it off. Riding back home, 20 minutes in, blasting my music, boom. Dynamic drive malfunction. The odd thing afterwards.. I had to run errands all day. Drove around for another 2 hours... no errors.. no flickering.. CD didnt even skip. I'm going to monitor this for a couple days. If I see it one more time, I'll go ahead and go through with the diag and registration question (I just assumed the BMW in Fresno would have registered it already). Thanks for all your help thus far HerbP- I see why your name is respected here.
 
#21 ·
If your cooling fan is failing, the engine will run hot at stop signs or lights. To verify this, simply get to check & see if the fan is running. If the fan is not, your cooling fan is probably shot. The fan failure usually shows up in warmer weather. If you continue to run the engine hot, your expansion tank will most likely fail. The cooling fan can be purchased from Amazon, or your local O'Reillly's with lifetime warranty. You can negotiate your prices with your local BMW. They don't like to do this, but some money is better than no money!

Check out your fan!
 
#23 ·
Based on my observations, it usually take the engine 15 to 20 minutes to get up to operating temp. As you are traveling down the road, the cooling fan is not really needed. When at slow speeds or frequent stops, this is when the fan needs to work. When my fan failed, it always worked for around 20 minutes. After that, the fan stopped working when the engine got warm. There are actually 4 operating speeds on the fan. DIS or INPA can test each speed as part of the test cycle. The relay built into the electrical connector on the fan, usually fails.

Good Luck!
 
#27 ·
Take the car to any auto parts store, & ask them to test for a bad alternator or battery. They should be able to do this for free. If you should need to use a multimeter, most parts houses would have one to use. Do the cheap test first, then let us know what the results are.

Good Luck!
 
#28 ·
Hey guys, sorry for the delay. So here's the update:

I was riding to a friends house about 30 minutes away when my system went haywire. Idrive flashing again, ABS light came on, dynamic drive malfunction, then the power steering disabled! I pulled over just in time, restarted the car and never saw that again.
I tested the alternator, and I got 13.8V at idle, but the mechanic said I "averaged" 13.8 when rev'd. According to all or nothing and my latest incident.. I would say the alternator needs replacement. Is the car safe to drive lightly? The battery tested fine- it is still getting charge, and all diodes were fine.
 
#29 ·
It is your alternator I just had the same problem. I had it replaced and all is good. Mine would charge for 3 minutes then die out, and suck up battery power. Yours is intermittent and could go at anytime, like mine did and I had to get towed home, not fun.
Just change it I had mine done for $400. parts included. Car drives like never before, I have my valve covers leaking I think the oil dripped into the alternator and caused it to fail. Are your valve covers leaking too!!!
 
#31 ·
It was actually like $468.00 my cousin works at sears auto and they have a master tech there that has tons of BMW experience his son is BMW tech as well. I asked my cousin to give me a quote and it was cheap so I said go for it! I used my cousins discount to knock off about 40 bucks.
They put in the exact same part that was in it too. They did a great job!
Dealer wanted 668.00 just for the part !!!
 
#37 ·
I'm not saying they fail because of the heat. I'm saying the voltage readings fluctuates out of spec when they get to normal operating temperature due to failed voltage regulators. Why the regulators fail, I don't know. I do know its very common on the N62, N62tu engines. It could just be crappy alternators. I would say half of the ones I have replaced were soaked in oil due leaking upper timing case cover gaskets, so that could be the cause also.
 
#38 ·
This thread is 36 posts too long.

Alternator. /thread.
 
#39 ·
Not exactly. I just replaced the alternator today. OEM Valeo, brand new from buyautoparts. After installation, all voltages checked out fine with AC running, radio, lights.. everything. 30 minutes driving home, dynamic drive malfunction (keep in mind, I bought a CTEK 3300, and charged it to green LAST NIGHT). Battery is fine- AGM, 1 month old and registered.

I took the car immediately back, and the tech ran a diag. The only thing that even showed as semi-suspicious was a "low voltage on the DCS" .. first time I'm heard of this. Also, before the alternator replacement, my DMTL pump caused the increased emissions light to come on. Tech told me it shouldn't affect driveability. He cleared the faults, restarted the car nothing. I drove away.. 15 minutes.. dynamic drive again. Does anyone have ideas outside the alternator now?
 
#40 ·
There is a chance you have a bad IVM (integrated voltage module). I've seen a few people with this problem. Similar to having a bad alternator. Do a google search for more info.

You could also have a problem with a bad ground or a bad connection (corrosion) on one of the main battery cables.
 
#41 ·
While troubleshooting my Dynamic Drive problems, I found that the circuit 30 which powers the Dynamic Drive module, was seeing high voltage spikes. These spikes are basically seen when the voltage regulator is seeing very little load. This was after a 20 minute drive, when the battery is fully charged. For some reason it happens more in colder weather. I was looking at buying that same alternator, but decided to replace just the voltage regulator. If the Dynamic Drive is showing faults while driving, you could have a bad Lateral Acceleration problem, or a bad new voltage regulator. There is a thread posted in my thread worth reading. Testing the Dynamic Drive might show a over voltage error, which would not allow the Dynamic Drive to reset. The system should also be re-commissioned after clearing all errors related to the Dynamic Drive.

Hope this might help!

Good Luck!
 
#43 ·
Check Engine Increased Emissions

bmwoem1 is exactly right I'd say. Right after passing my state emissions testing, I started receiving Tghten Gas Cap message, I tightened gas cap and light went away. Later that day I went over speed bumps and got hat flash of light on my dash as I went over each opne. With continued driving the next few days that light flashing briefly with a speed bump seemed erratic. Then I suddenly got Check Engine Soon light, increased emissions for about a week now. Car drove OK, no loss of power, stuttered only once or twice when I started it. I was thinking Emissions all the way. So I removed, replaced (new gas cap)and tightened gas cap, filled up tank with "new gas" drove about 400 miles (this was suggested by a mechanic) but error would not budge.

I went to the dealer on Friday and they found bad alternator and thermostat stuck open. They also asked when wa steh last time I replaced the battery (cant recall) but think battery might be OK once alternator is installed and battery rechecked.

Car is still at dealer until tomorrow. But I think it's interesting I had the exact same issues mentioned and my dealer (after running full diagnostics) came up with bad alternator, just like bmwoem1 suggested. The damage BTW is around 2K. Ouch!!
 
#44 ·
bmwoem1 is exactly right I'd say. Right after passing my state emissions testing, I started receiving Tghten Gas Cap message, I tightened gas cap and light went away. Later that day I went over speed bumps and got hat flash of light on my dash as I went over each opne. With continued driving the next few days that light flashing briefly with a speed bump seemed erratic. Then I suddenly got Check Engine Soon light, increased emissions for about a week now. Car drove OK, no loss of power, stuttered only once or twice when I started it. I was thinking Emissions all the way. So I removed, replaced (new gas cap)and tightened gas cap, filled up tank with "new gas" drove about 400 miles (this was suggested by a mechanic) but error would not budge.

I went to the dealer on Friday and they found bad alternator and thermostat stuck open. They also asked when wa steh last time I replaced the battery (cant recall) but think battery might be OK once alternator is installed and battery rechecked.

Car is still at dealer until tomorrow. But I think it's interesting I had the exact same issues mentioned and my dealer (after running full diagnostics) came up with bad alternator, just like bmwoem1 suggested. The damage BTW is around 2K. Ouch!!
I strongly suggest you get a good indy and don't let the dealer do the work. Now that my extended maint/service is up, I've been using a great indy shop here in Marietta. For example, Global quoted me $650 to replace the spark plugs and my indy did all of them with the same plugs for $239. Happy to recommend them to you if you send me a pm.
 
#48 ·
I had some electrical problem that were intermittent. My BMW was under warranty but after three-four attempts, I was feed up of driving it back there. I had what appeared to be some type of voltage or grounding problem. The SRS air bag light would come on, transmission failure, dash warning lights coming on, the dome lights flickering, and a few other strange things would going on. I figured it was some type of voltage problem or a module going bad. Since I worked on vehicle electronics in my earlier days, I decided to try to track it down my self. It was a huge task and I checked every ground point looking for loops or corrosion. I also hooked up a volt meter and drove the car looking for drops or spikes. No problems with the battery or alternator was detected. It was hard to trace since the problem was intermittent. Sometimes the car would run fine all day, sometimes a few hours. I finally traced it to the ignition switch. I can't remember which pin or wire it was, but one of the ignition contacts had a bunch of carbon from arching. The carbon cause resistance and would it heat up. As it heated up, it would only allow for 7.8 volts to get to the other side. This caused a bunch of components to fail due to the low voltage. I ran a jumper wire bypassing the switch to confirm the problem. I replaced the ignition switch and the problem was solved.
 
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