BMW M5 Forum and M6 Forums banner

1 - 8 of 8 Posts

·
Registered
Joined
·
3 Posts
Discussion Starter #1
I have a 2000 M5 with 102k on the clock. Drove it about 50 miles, put gas in it, drove another 10 miles and stopped for an hour. When I got back in, the tach was jumping around the low end and it stalled out a few times. Felt like it wasn't making good power. After a while I got it started again, and drove it. Thought it was bad gas (WV), so I put in water remover and have been refilling the tank to dilute it. I have definitely ran all of the bad gas out of it, but am still having the same problem. Rough idle, weak power at startup, but it seems to go away after it warms up.Check engine light is on.

I ran the codes and got the following:

P0175/0172 (system too rich, banks 1&2)
P1342
P1344
P1346
P1348
P1354
P1350
P1356
All of these are "misfire during start" for each cylinder.

P0316 (engine misfire detected on startup)

The car is fully stock and the plugs were changed about 2000 miles ago.

Any ideas?
 

·
Registered
Joined
·
62 Posts
I have a 2000 M5 with 102k on the clock. Drove it about 50 miles, put gas in it, drove another 10 miles and stopped for an hour. When I got back in, the tach was jumping around the low end and it stalled out a few times. Felt like it wasn't making good power. After a while I got it started again, and drove it. Thought it was bad gas (WV), so I put in water remover and have been refilling the tank to dilute it. I have definitely ran all of the bad gas out of it, but am still having the same problem. Rough idle, weak power at startup, but it seems to go away after it warms up.Check engine light is on.

I ran the codes and got the following:

P0175/0172 (system too rich, banks 1&2)
P1342
P1344
P1346
P1348
P1354
P1350
P1356
All of these are "misfire during start" for each cylinder.

P0316 (engine misfire detected on startup)

The car is fully stock and the plugs were changed about 2000 miles ago.

Any ideas?




Sent from my iPhone using Tapatalk
 

·
Registered
Joined
·
62 Posts
I have a 2000 M5 with 102k on the clock. Drove it about 50 miles, put gas in it, drove another 10 miles and stopped for an hour. When I got back in, the tach was jumping around the low end and it stalled out a few times. Felt like it wasn't making good power. After a while I got it started again, and drove it. Thought it was bad gas (WV), so I put in water remover and have been refilling the tank to dilute it. I have definitely ran all of the bad gas out of it, but am still having the same problem. Rough idle, weak power at startup, but it seems to go away after it warms up.Check engine light is on.

I ran the codes and got the following:

P0175/0172 (system too rich, banks 1&2)
P1342
P1344
P1346
P1348
P1354
P1350
P1356
All of these are "misfire during start" for each cylinder.

P0316 (engine misfire detected on startup)

The car is fully stock and the plugs were changed about 2000 miles ago.

Any ideas?
Sorry for the double post. Sounds like your VANOS solenoids need a cleaning, resealing, and possibly solder job. You can read more here:



Sent from my iPhone using Tapatalk
 

·
Registered
Joined
·
3 Posts
Discussion Starter #4
Could be, but the fault codes don't seem to match up. If it were the VANOS wouldn't I expect to see:
  • P1520: Camshaft position actuator, exhaust
  • P1523: Camshaft position actuator is jammed, exhaust
  • P1397: Camshaft position sensor B
I'm not getting any of those codes. All of the codes I am getting seem to refer to a fuel/air problem. Think it could be MAF sensor?
 

·
Registered
Joined
·
9,833 Posts
Could be, but the fault codes don't seem to match up. If it were the VANOS wouldn't I expect to see:
  • P1520: Camshaft position actuator, exhaust
  • P1523: Camshaft position actuator is jammed, exhaust
  • P1397: Camshaft position sensor B
I'm not getting any of those codes. All of the codes I am getting seem to refer to a fuel/air problem. Think it could be MAF sensor?
You might expect to see those codes but they will not show up if the solenoids still function electrically but are plugged up.
That is not where to start that is where you go when other things don't pan out.
The first things you need to confirm is fuel supply and air readings.
The first check is to jump in the car with a part tank and go to the secret menu where it shows the level of both tanks. With watch in hand time a minute and see exactly how much fuel is transferred from the drivers tank to passenger tank. IIRC 2liter/min is near right. If it is not that you might have a fuel supply issue and other test would be run.
Next you would unplug the MAFs electrically and drive the car and see if it behaves differently. You need to drive it for a while to readjust the fuel trims, just a short hitch will do little. The car will still use the old adaptions and the car may still run poorly although it would be different.
Report those and we can see where that takes us. I suspect with your fuel codes unplugging the MAFs will make a large change in how the car behaves which would indicate one or both of your MAFs are very tired and need replacing.
 

·
Registered
Joined
·
3 Posts
Discussion Starter #6
You might expect to see those codes but they will not show up if the solenoids still function electrically but are plugged up.
That is not where to start that is where you go when other things don't pan out.
The first things you need to confirm is fuel supply and air readings.
The first check is to jump in the car with a part tank and go to the secret menu where it shows the level of both tanks. With watch in hand time a minute and see exactly how much fuel is transferred from the drivers tank to passenger tank. IIRC 2liter/min is near right. If it is not that you might have a fuel supply issue and other test would be run.
Next you would unplug the MAFs electrically and drive the car and see if it behaves differently. You need to drive it for a while to readjust the fuel trims, just a short hitch will do little. The car will still use the old adaptions and the car may still run poorly although it would be different.
Report those and we can see where that takes us. I suspect with your fuel codes unplugging the MAFs will make a large change in how the car behaves which would indicate one or both of your MAFs are very tired and need replacing.


I cleaned the MAF sensors and the air boxes and cleared the codes. Started it up and it stalled a couple times but then the idle seemed much better. I took it for a test drive and it made considerably more power. I let it sit overnight and when I cold started it today it did a tiny bit of rev hunting but has driven great, and still seems to make much more power. No CEL yet, and no codes have been thrown.

Has anyone had much luck with cleaning the MAF sensors as opposed to replacing them entirely? I can see that one was clearly replaced from the tool marks on the torx nut. Just wondering if its worth replacing them, since they are only about $260 for both.
 

·
Registered
Joined
·
9,833 Posts
I cleaned the MAF sensors and the air boxes and cleared the codes. Started it up and it stalled a couple times but then the idle seemed much better. I took it for a test drive and it made considerably more power. I let it sit overnight and when I cold started it today it did a tiny bit of rev hunting but has driven great, and still seems to make much more power. No CEL yet, and no codes have been thrown.

Has anyone had much luck with cleaning the MAF sensors as opposed to replacing them entirely? I can see that one was clearly replaced from the tool marks on the torx nut. Just wondering if its worth replacing them, since they are only about $260 for both.
Cleaning MAFs is not a very reliable test. At best you might see some results from it but it only indicates that something inside the device is not up to spec, They are pretty complicated and it is near impossible to know what is wrong. Unplugging them is more reliable since the car has programming to run the car without MAFs. Since you did get results cleaning them it is still a good indication there is something wrong, cleaning MAFs that are good will show no results, so the change you see might indicate something. The change from unplugging them is a better indication and more reliable.
Even a change with cleaning them is a good hint you need to replace them. The market has a lot of fakes out there so base your choice on the credibility of the seller not the price. There are so many fakes, some even with the correct seal on the box.
 

·
Registered
Joined
·
211 Posts
When my 2001 started acting like that, I tore everything down to the throttle bodies and did the following:

All 4 CPS sensors
Both TPS sensors
New MAFs
New air filters
Rebuilt fuel injectors and all new O-rings
New Fuel Pump
New Fuel Filter
New fan clutch/fan
New Vanos O-rings / Cleaned solenoids / Reinforced solder joints
New Thermostat & O-Rings
New Thermostat temp sensor
New Radiator temp sensor
New Radiator hoses
Full block drain / coolant flush
New Valve Cover Gaskets
New Spark Plugs
New Chain tensioner
New Power Steering Reservoir
New Power Steering Lines
All new oil separator and vacuum lines
replaced plastic vacuum elbow with a brass fitting
Completely cleaned / degreased oil separators and intake plenum
Deep cleaned throttle bodies
Had valve covers powder coated.

This was wasn't so much 'throwing parts at the problem' but knowing that a 20 year old car with 100kmi+ is going to need all this stuff soon anyway, especially if I want to keep it in top shape for a long time.

It also gave me the opportunity to really get to know the car under the hood, and finely detail the engine bay.

Once I got everything back together - the car runs like a dream. Even that 'Vanos Diesel Rattle' that I hope to address some day with new gears was significantly reduced.

-A77
 
1 - 8 of 8 Posts
About this Discussion
7 Replies
4 Participants
Awake77
BMW M5 Forum and M6 Forums
M5Board is the best forum community for information on the BMW M5 E60 (V-10), E39 (V-8), E34 (straight 6), E28, F90 and F10. Discuss performance, specs, reviews and more!
Full Forum Listing
Top