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Ont. and NFLD. I don't really look at peoples cars though any more. I have a backlog of cars I built that I have not had time to look at.
So unplug the 4 sensors and you can plug them into each other to keep things tidy and not hanging down.
12.3V and the car started? Is it going to sleep? Check right after a drive and then the next morning or even a few hours later then again a few more. Just to establish a rate of decline. Then one time after a drive disconnect the neg term so the battery is disconnected and see what the volts are the next morning. It might not be the battery it could be a rodent made short some where in the car drawing some power. Depending where the short is that could explain a lot. It also does not have to be a short to ground it can be one positive wire shorted to another positive wire. That can make things power that should not be powered. I would keep looking for rodent nests or droppings.They seem to love it in the dash but also under the plenum, lots of places have been reported
 

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Discussion Starter · #22 ·
Ont. and NFLD. I don't really look at peoples cars though any more. I have a backlog of cars I built that I have not had time to look at.
So unplug the 4 sensors and you can plug them into each other to keep things tidy and not hanging down.
12.3V and the car started? Is it going to sleep? Check right after a drive and then the next morning or even a few hours later then again a few more. Just to establish a rate of decline. Then one time after a drive disconnect the neg term so the battery is disconnected and see what the volts are the next morning. It might not be the battery it could be a rodent made short some where in the car drawing some power. Depending where the short is that could explain a lot. It also does not have to be a short to ground it can be one positive wire shorted to another positive wire. That can make things power that should not be powered. I would keep looking for rodent nests or droppings.They seem to love it in the dash but also under the plenum, lots of places have been reported
Yes, the car starts perfectly. I'm not sure if it is going to sleep but I do think I have a voltage drain somewhere, it used to be the part under the dash ( FSU I believe it's called ) that I meant to change. I did experience the battery going flat on me before, am so NOT handy when it comes to electrical issues, but I will do my best to check. The car also has a front and rear camera that stays on constantly ( after someone hit to my front left fender a while back when I was at the gym made me install it. ( I know, Io shouldn't be taking the car to such places )

I did inspect the car for possible rodents per another post but I did not find anything indicating so. The battery the next day after standing should be at what voltage?

Unplugging 02s was suggested on another board as well, will do this first thing tomorrow morning. Maybe some wires are broken? When I erased the adaptations the car didn't smell and it seemed to have little more power, also returning very healthy numbers while on the highway in cruise at 55 mph ( 28mpg ) only slowly degrading down to 23 and by the time I pull into garage im at 14 mpg. I'm talking flat surface on a cruise and resetting the OBD. My 540 returns similar constantly and my 01 740 would hit the same numbers.

This is upsetting me because the car visually is spotless with so many brand new items down to door seals and all. In addition, the exhaust sound is not the same anymore. I will report my finding tomorrow. Btw, wouldn't resetting adaptation be the same as unplugging 02 Sensors? Do rear sensors matter at all ?

Thank you once more.
 

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There’s a problem with your Bank 1 upstream O2 sensor.
It shouldn’t be 0.35V.
It should be 0.44-0.46V like the other 3.
 

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The battery the next day after standing should be at what voltage?
Pretty much the exact same as when you unplugged it. Temp can effect the voltage, but not by much more than 0.1 or 0.2 Just make a note of the outside temp roughly.
Maybe some wires are broken?
Not likely but they don't throw codes when they are broken. You will notice the only code you get with them all unplugged is for the O2 heaters, not sure how that got missed.
Btw, wouldn't resetting adaptation be the same as unplugging 02 Sensors? Do rear sensors matter at all ?
For about 10 miles and then by 50 miles they will be 50% wrong again. It is very unwise to reset the adaptions unless you have a specific test to do. When things are not right the car does not adapt the same way it did. The DME can get confused on the re adapt.. I recognize in other forums people will tell you to do it first, but they are so wrong. I know from experience to avoid it at all costs. There are so many adaptions that get zero'd not just the fuel adaptions.

If you have done that you will have to do it again once the problem is found.
As far as the post O2 go, they have several jobs and one affects the vanos operation and the other will affect the fuel trim of the car. Other cars not so much but E39 M5 important roll. . I have a document some where that explains it I will see if I can find it.
 

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Discussion Starter · #25 · (Edited)
There’s a problem with your Bank 1 upstream O2 sensor.
It shouldn’t be 0.35V.
It should be 0.44-0.46V like the other 3.
They are new 02 sensors which performed perfectly before. What would be logical next step in my situation to address the voltage?
If you can, please explain further. Would unplugging the sensor reveal anything ? Why are adoptations off on both banks?
Thank you for catching this!

Video of 02 sensors

Are my post 02 sensors on? According to sailor they are important
 

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They are new 02 sensors which performed perfectly before. What would be logical next step in my situation to address the voltage?
If you can, please explain further. Would unplugging the sensor reveal anything ? Why are adoptations off on both banks?
Thank you for catching this!

Video of 02 sensors

Are my post 02 sensors on? According to sailor they are important
With the engine off and the ignition on the O2 sensors should read 0.44-0.46V.
The Bank 1 upstream sensor is reading 0.35V.
If you unplug it, INPA should read 0.45V - if it does, then your new sensor is faulty. If it doesn’t there’s a problem with the wiring or the DME.

Your adaptation values look fine to me.
 

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Discussion Starter · #29 ·
With the engine off and the ignition on the O2 sensors should read 0.44-0.46V.
The Bank 1 upstream sensor is reading 0.35V.
If you unplug it, INPA should read 0.45V - if it does, then your new sensor is faulty. If it doesn’t there’s a problem with the wiring or the DME.

Your adaptation values look fine to me.
Excellent, thank you sir. I will plug in my laptop and check the way you suggested, with motor off.

If the wiring is faulty, where would I check it? Could it be from recently installed headers? Could it be that wire kept rubbing on something and broke?
I just checked and is at .36v. I will lift the car up and disconnect it and swap it from left to right and see what happens.
 

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Discussion Starter · #30 · (Edited)
I unplugged the o2 sensor on passenger side before cat and I’m getting .46v in Impa. Does this indicate wiring issue or bad sensor because I changed the sensor before ( actually a well know shop did )

I also seem to have a slight exhaust leak on bank 2 after cat before 2nd 02sensor, would this effect performance?

In addition, what would kill the sensor? Is there another issue causing sensors to go bad, specifically on the passenger side?

952505
952506
 

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Discussion Starter · #32 · (Edited)
Update!
So I bought new sensor, plugged it without starting the car and voltage shows .46. I cleared the adaptations and will go for a drive later. Need to give it a good wash.
 

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Discussion Starter · #34 ·
What brand are you using?
Bosch


I drove the car about 6 miles and it runs just about the same. While driving I heard the exhaust burbling just like when CSPS fails.

although the sensor is running well the TQ especially down low hasn’t returned. Maybe I need to drive longer to adopt?

The burbling exhaust between shifts from 3rd to 4rd had me concerned, it was only for couple seconds but I did noticed. I installed new intake and exhaust CSPS about 30,000 miles ago.
 

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Bosch


I drove the car about 6 miles and it runs just about the same. While driving I heard the exhaust burbling just like when CSPS fails.

although the sensor is running well the TQ especially down low hasn’t returned. Maybe I need to drive longer to adopt?

The burbling exhaust between shifts from 3rd to 4rd had me concerned, it was only for couple seconds but I did noticed. I installed new intake and exhaust CSPS about 30,000 miles ago.
Are you comparing the TQ to before the Headers were fitted?
Because you lose a lot of light throttle torque with headers as they change the back pressure and VE massively.
 

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Discussion Starter · #36 ·
Are you comparing the TQ to before the Headers were fitted?
Because you lose a lot of light throttle torque with headers as they change the back pressure and VE massively.
I hardly noticed TQ loss with the evolve headers. I’ll have to put it on the dyno for accurate reading after 200 miles of driving.
I also never did a tune to accommodate for them plus hi flow cats. I remember being able to brake traction in 1st gear by going wide open throttle with clutch engaged, not anymore. Something else is going on.
 

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While driving I heard the exhaust burbling just like when CSPS fails.
Fix the exhaust leak before the post cat. Only god and maybe some BMW engineer knows exactly how that is changing vanos operation. Give it time and you may actually have to drive for 300 miles then clear the adaptions again, one of the reasons you should never clear the adaptions, it just does adapt like it does when the problem is first developing.
 

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Discussion Starter · #38 ·
Fix the exhaust leak before the post cat. Only god and maybe some BMW engineer knows exactly how that is changing vanos operation. Give it time and you may actually have to drive for 300 miles then clear the adaptions again, one of the reasons you should never clear the adaptions, it just does adapt like it does when the problem is first developing.
the exhaust leak is before the 2nd sensor, downstream, I’ll take a picture tomorrow.

My observations from driving around. The car for sure feels stronger but nothing close to what it was. The car used to struggle for traction in 1st gear and 2nd.

I drove probably 30 miles today and the longer I drove the more lazy the car felt, it feels like something is holding it back, going part throttle before would give smooth razor sharp acceleration, now it feels as if it was stuck in clue, or like a big rubber band was attached to the rear ( I think it’s rich ) I have to really press the go pedal to get it moving where before it was light tap and the car would just go.

Another thing I noticed as I drove around was that at the ref light the motor would slightly vibrate, and the hot idle numbers would go down to 1.5 -1.7 from standard 1.9-2.0 ( obc no 4, option 2 gives you this read out, I’ve been studying the forum posts :) )

Vanos were done by Chris at dr vanos few years back, and CSPS replaced. My friends car with similar mods put down 401whp on dyno jet and blew my doors off from the light. I absolutely love this car and had it for over a decade, bought it with very little miles and maintained it like it was my child.

Maybe I should find a good shop, but reading some of the posts here I rather not as most simply replace parts ( I read some horrible stories while searching for an answer )

What’s next? Unplug 02 sensors? Tomorrow I have a 100 mile trip, so I will take the M5 and put some miles on it. On a positive note, my instant mpg on cruise control went up to 25.3 from 21mpg.The sensor sure helped. I will address the leak tomorrow with exhaust tape for now till I can schedule it to put it on a lift.

what is the next logical step, could the CSPS not work properly, I know the sound it makes when it fails and although they are new, you newer know. I just hate throwing parts on the car without proper diagnostic.
Thank you again for all your help, and the other person for pointing out the 02 sensor issue.
 

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the exhaust leak is before the 2nd sensor, downstream, I’ll take a picture tomorrow.
I get that this is your baby but you are not helping yourself. I don't mean to give you ****e but... your screeners were horrible and you don't answer the questions and then you have an excuse for everything. I asked when the exhaust was smoked no answer but how did that leak not get noticed. If you don't present a clear picture of what is going on and answer peoples questions, how can they help you because only you have the car in front of you.
Fix what you can see is broken like the exhaust, test for other leaks, one thing at a time.
After your trip pull your new O2 out and see if it looks wet. How is your oil consumption, that will also make the O2 wet. Pull the other O2 and look at it.
Have you had the injectors ultra sonic cleaned? Not a suggestion, there is new evidence that removes a coating on some injectors, not sure if that coating is on our injectors, but I have sent out a few sets for cleaning and they all leaked. Usually you have hard start problems with leaking injectors, but not always. How fast does the car fire up? 1 sec or 2 for it to fire?
You don't have to throw parts at the car, but you have to do the work to diagnose it.
Does the car still smell bad? Pay attention on your drive tomorrow.
Last question, has the car been tuned for all these exhaust mods?
 
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