E39 CONSUMPTION? FINAL DIAGNOSTIC! UPDATE! HELPED!! SORTED!!!

[Truvalu]

Three wires is good ole narrowband sensors.

Two sensors before and after cat is OBDII system. (Your car has either three or four sensors depending on whether it has one or two cats).

As far as the before cat sensors are concerned

Bank I is cylinders 1-3

Bank II is cylinders 4-6

Carefull here! An O2 sensor error does not specifically mean the sensor is stuffed, it means the sensor is giving an out of specification fuel/air reading either because it is stuffed or something else in the injection system is not working correctly.

O2 sensor errors can be caused by:

Intake air leaks

Stuck injectors

Engine temparature sensor faults

A blocked catalytic converter

Bad or leaking fuel pressure regulator

A faulty engine ECU

A blocked air filter

A blocked fuel filter

and finally a fsked sensor

____________________________________

O2 sensor test

Remove the offending sensor/s

Get a multimeter, set it on volts so it can read between 0 and 1 V

White wires are the heater, ignore these.

Black wire is O2 output, connect to +ve of multimeter

Grey wire is ground, connect to -ve of multimeter

Stick a pin in the wires if you have to to get a connection.

Under no circumstances short the sensor or apply a voltage to it, both will kill it. Do NOT try to measure it's resistance Only measure it's voltage

Get a blowtorch

Gently heat the sensor tip (The part that's usually inside the exhaust) with the blowtorch till cherry red and watch the voltage.

____________________________

Diagnose sensor

No voltage or very low voltages or a very slow response (voltage change) if you remove the flame indicate it's stuffed

- voltages mean it's contaminated with silicone or antifreeze

A maximum of 0.9V with the blowtorch on the sensor tip dropping quick if you remove the torch means the sensor is working 100%

A maximum voltage of 0.7 to 0.9 is the useable range, any maximum below this, replace sensor

When the engine is running the voltage it wants is 0.45 (stochiometric lambda is 14.7 air to 1 part fuel, the perfect mix to burn everything) and it swings up and down just around this point.

Less than 0.45 is mixture too lean

More than 0.45 is mixture too rich

_______________________

Narrow band sensors are available in 1,2,3 and 4 wire versions heated and non heated and floating ground or grounded, 12watt or 19 watt heaters.

As long as you get the same type, you can fit any damn sensor from any car as a substitute and it will work just fine. I'll risk being flamed and go as far as to say, you can chuck any damn narrow band sensor in there, even a 1 wire one and it will at least work.

You do not have to spend like 10K at the dealers to sort this O2 sensor issue out, it is possible to make a plan


Hope this helps

Thanks a lot Rick!

This is scary for me!

This is the only vehicle I have and I have serious budget restraints.

I don't have a garage or somewere proper to get under the car and just for now maybe just disconnect the sensor for now.... I think the one nearest to the engine? Could that make a difference or is it bad for her? Should I try and have the cats removed.... quoted R 300 at SupaQuick Paarl, but on my own risk???????

I recently added fuelsystem cleaner to my tank, could that be what is making it smoking very, very slightly whilst idling at length.

The person who did the diagnostic said his system could not "get into" the sensor to read it.
I asked him if he could set the auto door lock function and he started searching all over the program.... that is when I realized that he has little experience with BMW's he tells me lots of things he has done wit VW's and Opels on his machine....

I am seriously sad, but thankfull for your help so far.

I think I need some attention to the front suspension to. Some creaking noises when i turn the steering at parking speed.

 

[rick540]

Check if there are two sensors near the engine, if you unplug, unplug both, not just one.

It will throw a check engine light, and should be repaired as soon as possible, but by the sounds of it, it is going to run far better on defaults with the things unplugged.

I recomend an oil change as well, running so rich it has probably diluted the oil with fuel.

If you are ever in Somerset West I will be happy to read the codes for you, see if we can get to the bottom of this.

The only way to test the cats properly is to actually measure the pressure upstream. I wouldn't remove them yet unless you are 100% sure they are a problem.

 

[Truvalu]

Check if there are two sensors near the engine, if you unplug, unplug both, not just one.

It will throw a check engine light, and should be repaired as soon as possible, but by the sounds of it, it is going to run far better on defaults with the things unplugged.

I recomend an oil change as well, running so rich it has probably diluted the oil with fuel.

If you are ever in Somerset West I will be happy to read the codes for you, see if we can get to the bottom of this.

The only way to test the cats properly is to actually measure the pressure upstream. I wouldn't remove them yet unless you are 100% sure they are a problem.

It seems to me the oil is quite thin... you are correct AGAIN!!!!

PM'd you

 

[rick540]

Well Truvalu showed up today, nice to meet you finally Philip, had a good chat.

What a beautifull example of a 528i, cleanest one I have ever seen, really guys you have got to see this car.

Ran all diagnostics, O2 sensor bank 1 is definitly stuffed.

Got a VANOS is jammed error, till I removed and refitted the connector with contact cleaner, then it appeared to be working on the liva data and the error dissapeared I hope for good. The camshaft advance live data seemed to confirm the fix as there was almost 15 degrees movement afterwards.

Ran a smooth running test and the engine scored as close to 100% as I have ever seen, engine itself is in top condition and very quiet.

Every other item on the engine is ship shape and within specification.

The NTK/NGK O2 sensor is actally a four wire Siemens device # no 1178 1 427 884

Can anybody tell me it it is a wide or narrow band sensor, I'm trying to work this out in order to help truvalu to possibly do a low cost fix as opposed to a dealer 5K fix.

 

[Truvalu]

Well Truvalu showed up today, nice to meet you finally Philip, had a good chat.

What a beautifull example of a 528i, cleanest one I have ever seen, really guys you have got to see this car.

Ran all diagnostics, O2 sensor bank 1 is definitly stuffed.

Got a VANOS is jammed error, till I removed and refitted the connector with contact cleaner, then it appeared to be working on the liva data and the error dissapeared I hope for good. The camshaft advance live data seemed to confirm the fix as there was almost 15 degrees movement afterwards.

Ran a smooth running test and the engine scored as close to 100% as I have ever seen, engine itself is in top condition and very quiet.

Every other item on the engine is ship shape and within specification.

The NTK/NGK O2 sensor is actally a four wire Siemens device # no 1178 1 427 884

Can anybody tell me it it is a wide or narrow band sensor, I'm trying to work this out in order to help truvalu to possibly do a low cost fix as opposed to a dealer 5K fix.

Hi Guys, and Rick..... thanks bud you are the greatest!

What an experience!

This guy's got magic!

I never thought you could still find salt of the earth like this man...

What he has forgotten about these cars, many of us still have to learn.

It was heavy traffic from Somerset-West to Durbanville via Stellenbosch and then traffic to Paarl, but my obc shows 12L/100km from resetting it to zero in Somerset-West.
Tommorow I'll be driving to Parow and back and will have a better idea of what it does at average of 100km/h, 116km/h and 120km/h.

Thank you Rick!

We're not finished yet.........

 

[rick540]

Well Truvalu showed up today, nice to meet you finally Philip, had a good chat.

What a beautifull example of a 528i, cleanest one I have ever seen, really guys you have got to see this car.

Ran all diagnostics, O2 sensor bank 1 is definitly stuffed.

Got a VANOS is jammed error, till I removed and refitted the connector with contact cleaner, then it appeared to be working on the liva data and the error dissapeared I hope for good. The camshaft advance live data seemed to confirm the fix as there was almost 15 degrees movement afterwards.

Ran a smooth running test and the engine scored as close to 100% as I have ever seen, engine itself is in top condition and very quiet.

Every other item on the engine is ship shape and within specification.

The NTK/NGK O2 sensor is actally a four wire Siemens device # no 1178 1 427 884

Can anybody tell me it it is a wide or narrow band sensor, I'm trying to work this out in order to help truvalu to possibly do a low cost fix as opposed to a dealer 5K fix.

Hi Guys, and Rick..... thanks bud you are the greatest!

What an experience!

This guy's got magic!

I never thought you could still find salt of the earth like this man...

What he has forgotten about these cars, many of us still have to learn.

It was heavy traffic from Somerset-West to Durbanville via Stellenbosch and then traffic to Paarl, but my obc shows 12L/100km from resetting it to zero in Somerset-West.
Tommorow I'll be driving to Parow and back and will have a better idea of what it does at average of 100km/h, 116km/h and 120km/h.

Thank you Rick!

We're not finished yet.........

You're welcome Philip anytime.

At least you have peace of mind there's nothing major wrong, a sensor or two and it will be perfect. Hopefully the VANOS will behave now as well.

 

[Truvalu]

I just know that with your help and that of the rest of these guys, we are going to make this a masterpiece.

Thanx again

 

[Truvalu]

Titania sensor
A less common type of narrow-band lambda sensor has a ceramic element made of titanium dioxide (titania). This type does not generate its own voltage, but changes its electrical resistance in response to the oxygen concentration. The resistance of the titania is a function of the oxygen partial pressure and the temperature. Therefore, some sensors are used with a gas temperature sensor to compensate for the resistance change due to temperature. The resistance value at any temperature is about 1/1000th the change in oxygen concentration. Luckily, at lambda = 1, there is a large change of oxygen, so the resistance change is typically 1000 times between rich and lean, depending on the temperature.

As titania is an N-type semiconductor with a structure TiO2-x, the x defects in the crystal lattice conduct the charge. So, for fuel-rich exhaust the resistance is low, and for fuel-lean exhaust the resistance is high. The control unit feeds the sensor with a small electrical current and measures the resulting voltage across the sensor, which varies from near 0 volts to about 5 volts. Like the zirconia sensor, this type is nonlinear, such that it is sometimes simplistically described as a binary indicator, reading either "rich" or "lean". Titania sensors are more expensive than zirconia sensors, but they also respond faster.

In automotive applications the titania sensor, unlike the zirconia sensor, does not require a reference sample of atmospheric air to operate properly. This makes the sensor assembly easier to design against water contamination. While most automotive sensors are submersible, zirconia-based sensors require a very small supply of reference air from the atmosphere. In theory, the sensor wire harness and connector are sealed. Air that leaches through the wire harness to the sensor is assumed to come from an open point in the harness - usually the ECU which is housed in an enclosed space like the trunk or vehicle interior.

 

[Philip Foglar]

Hi Philip,

Not too familiar with the 528i in terms of consumption and referring back to an October '96 CAR mag review of the 5 speed manual 528i these were their figures which were factory supplied figures:

DIN 90 km/h = 6.3 l/100 km
DIN urban = 11.8 l/100 km
DIN average = 8.6 l/100 km
EC overall = 9.9 l/100 km

From their review:

"We were unable to plumb (I think they meant plug) our fuel flowmeter into the 528i's system, so no steady-speed consumption measurements were possible. However, tank-to-tank comparisons resulted in an average of about 13 litres/100 km in a mixture of (fairly brisk) town and freeway driving. Factory-supplied figures state that according to DIN standards the 528i consumes 7.8 litres/100 km at a steady 120, and 11.8 on the urban cycle. The stiffer EC standard shows an in-town consumption of 14.2 litres/100 km and 9.9 overall."

Just out of interest, other stats:

0-60 = 3.57
0-80 = 5.57
0-100 = 8.02
0-120 = 11.24
1km sprint = 28.90 sec and 183.5 km/h
Max speed 229 km/h (true speed) - 240 km/h (indicated on speedometer)

100-120 = 5.03 4th and 7.06 5th gear
120-140 = 5.22 4th and 7.59 5th gear

Apart from the E46 328i I have always had a crush on these 528i's! I would think your consumption should be like mine pretty good on the open road and a bit heavier in town and traffic - the 330i seems to be around 11-12 l/100 km for me around town (the Durbanville area). So slightly bigger and heavier 528i shouldn't be much higher - my Father-in-law has an E46 328i automatic and says that its consumption is pretty close to what I am getting with the 330i.

Hope you get her back to good health soon and without costing an arm and a leg!

Philip

 

[rick540]

Titania sensor
A less common type of narrow-band lambda sensor has a ceramic element made of titanium dioxide (titania). This type does not generate its own voltage, but changes its electrical resistance in response to the oxygen concentration. The resistance of the titania is a function of the oxygen partial pressure and the temperature. Therefore, some sensors are used with a gas temperature sensor to compensate for the resistance change due to temperature. The resistance value at any temperature is about 1/1000th the change in oxygen concentration. Luckily, at lambda = 1, there is a large change of oxygen, so the resistance change is typically 1000 times between rich and lean, depending on the temperature.

As titania is an N-type semiconductor with a structure TiO2-x, the x defects in the crystal lattice conduct the charge. So, for fuel-rich exhaust the resistance is low, and for fuel-lean exhaust the resistance is high. The control unit feeds the sensor with a small electrical current and measures the resulting voltage across the sensor, which varies from near 0 volts to about 5 volts. Like the zirconia sensor, this type is nonlinear, such that it is sometimes simplistically described as a binary indicator, reading either "rich" or "lean". Titania sensors are more expensive than zirconia sensors, but they also respond faster.

In automotive applications the titania sensor, unlike the zirconia sensor, does not require a reference sample of atmospheric air to operate properly. This makes the sensor assembly easier to design against water contamination. While most automotive sensors are submersible, zirconia-based sensors require a very small supply of reference air from the atmosphere. In theory, the sensor wire harness and connector are sealed. Air that leaches through the wire harness to the sensor is assumed to come from an open point in the harness - usually the ECU which is housed in an enclosed space like the trunk or vehicle interior.

That is awsome info, well researched, makes perfect sense now considering the voltages I was seeing, thanks!

I have come across them before, but never took too much notice, they are actually quite uncommon, and I still need to devise a test, then maybe I can organise you a working one. As far as I could research tonight they are only made by NTK and were only used by BMW utilising the Siemens fuel injection systems.

It appears the broken one in your car is open circuit as it is not lowering that 4.83V we were seeing. Unplugging them to cause a default will not work here as it just goes rich at the higher voltages.

Interstingly I remember titanium dioxide is also what they use in white paint to make it brilliant white.

 

[Truvalu]

Titania sensor
A less common type of narrow-band lambda sensor has a ceramic element made of titanium dioxide (titania). This type does not generate its own voltage, but changes its electrical resistance in response to the oxygen concentration. The resistance of the titania is a function of the oxygen partial pressure and the temperature. Therefore, some sensors are used with a gas temperature sensor to compensate for the resistance change due to temperature. The resistance value at any temperature is about 1/1000th the change in oxygen concentration. Luckily, at lambda = 1, there is a large change of oxygen, so the resistance change is typically 1000 times between rich and lean, depending on the temperature.

As titania is an N-type semiconductor with a structure TiO2-x, the x defects in the crystal lattice conduct the charge. So, for fuel-rich exhaust the resistance is low, and for fuel-lean exhaust the resistance is high. The control unit feeds the sensor with a small electrical current and measures the resulting voltage across the sensor, which varies from near 0 volts to about 5 volts. Like the zirconia sensor, this type is nonlinear, such that it is sometimes simplistically described as a binary indicator, reading either "rich" or "lean". Titania sensors are more expensive than zirconia sensors, but they also respond faster.

In automotive applications the titania sensor, unlike the zirconia sensor, does not require a reference sample of atmospheric air to operate properly. This makes the sensor assembly easier to design against water contamination. While most automotive sensors are submersible, zirconia-based sensors require a very small supply of reference air from the atmosphere. In theory, the sensor wire harness and connector are sealed. Air that leaches through the wire harness to the sensor is assumed to come from an open point in the harness - usually the ECU which is housed in an enclosed space like the trunk or vehicle interior.

That is awsome info, well researched, makes perfect sense now considering the voltages I was seeing, thanks!

I have come across them before, but never took too much notice, they are actually quite uncommon, and I still need to devise a test, then maybe I can organise you a working one. As far as I could research tonight they are only made by NTK and were only used by BMW utilising the Siemens fuel injection systems.

It appears the broken one in your car is open circuit as it is not lowering that 4.83V we were seeing. Unplugging them to cause a default will not work here as it just goes rich at the higher voltages.

Interstingly I remember titanium dioxide is also what they use in white paint to make it brilliant white.

Thanks Rick....

I will try and find the url where I got it from.... think it was wikopedia.

The explanation of when it has higher voltage reading or lower as in rich or lean is one of those sentences that tests the limit of my namaqualand english. Is it higher voltage when richer or when leaner?

it is like someone asking a question where you don't know to answer yes or no as the question is so confusing negative or positive..

have a good day!

 

[rick540]

So, for fuel-rich exhaust the resistance is low, and for fuel-lean exhaust the resistance is high.(Resistance of the Titania sensor)

Refering to a typical resistor Wein bridge circuit they like to use A low resistance will cause a low voltage for a rich condition.

But then again it could easily be the opposite as it totally depends on the feedback circuit around the O2 sensor.

So for now trying to find technical documents on the Siemens MS41 fuel injection system to see exactly which one it is.

 

[Truvalu]

Fuel consumption now on 13.3L/100km since Rick's Magic

 

[Truvalu]

Well Truvalu showed up today, nice to meet you finally Philip, had a good chat.

What a beautifull example of a 528i, cleanest one I have ever seen, really guys you have got to see this car.

Ran all diagnostics, O2 sensor bank 1 is definitly stuffed.

Got a VANOS is jammed error, till I removed and refitted the connector with contact cleaner, then it appeared to be working on the liva data and the error dissapeared I hope for good. The camshaft advance live data seemed to confirm the fix as there was almost 15 degrees movement afterwards.

Ran a smooth running test and the engine scored as close to 100% as I have ever seen, engine itself is in top condition and very quiet.

Every other item on the engine is ship shape and within specification.

The NTK/NGK O2 sensor is actally a four wire Siemens device # no 1178 1 427 884

Can anybody tell me it it is a wide or narrow band sensor, I'm trying to work this out in order to help truvalu to possibly do a low cost fix as opposed to a dealer 5K fix.

Hi Guys, and Rick..... thanks bud you are the greatest!

What an experience!

This guy's got magic!

I never thought you could still find salt of the earth like this man...

What he has forgotten about these cars, many of us still have to learn.

It was heavy traffic from Somerset-West to Durbanville via Stellenbosch and then traffic to Paarl, but my obc shows 12L/100km from resetting it to zero in Somerset-West.
Tommorow I'll be driving to Parow and back and will have a better idea of what it does at average of 100km/h, 116km/h and 120km/h.

Thank you Rick!

We're not finished yet.........

You're welcome Philip anytime.

At least you have peace of mind there's nothing major wrong, a sensor or two and it will be perfect. Hopefully the VANOS will behave now as well.

So there we had the DR check up on his magic and..... there is not one Fault code!!!!

Dr Rick says the fuel system cleaner could also be the final medicine that was needed to have the o2 sensor all it's chirpy self again..

I drive normally and the fuel consumption is steady at average of about 13.3L/100km, mostly town driving...

Thanks Dr Rick!!

 

[E39 Ian]

:thumbsup:

 

[rick540]

That was kind of wierd..... The O2 sensor just came back to life all by itself......., we need to keep an eye on that

Maybe it was when I cleaned out the connectors with contact cleaner, anyways she is ship shape acording to the diagnostics now.

Still an intermittent VANOS jammed error, but everytime I run the diagnostics, the VANOS is moving through it's full range..... wierd #2 Maybe it's only when cold, let's keep an eye on that too.

No worries though, as long as the fuel consumption remains low everything is working just fine. BMW's are a bit quirky this way, it's "normal" for them.

_______________________

This teaches me a lesson, NEVER change stuff after only one diagnostic, monitor it over a few weeks to see if the error is "real" or fake. Sometimes cars stand for too long, give errors when they are driven again, sometimes a bad batch of fuel or old fuel or even a bit of moisture in the fuel, sometimes an oil change cures things, sometimes they just need some good runs on the highway to blow out the cobwebs from granny driving.

All of this stuff can cause diagnostic errors that go away after some good driving on the highway and a few clean batches of fuel or oil.

Diagnostic errors are usually only about 50% accurate, do not waste your money till you are 100% sure an item has actually genuinely failed.

 

[Truvalu]

That was kind of wierd..... The O2 sensor just came back to life all by itself......., we need to keep an eye on that

Maybe it was when I cleaned out the connectors with contact cleaner, anyways she is ship shape acording to the diagnostics now.

Still an intermittent VANOS jammed error, but everytime I run the diagnostics, the VANOS is moving through it's full range..... wierd #2 Maybe it's only when cold, let's keep an eye on that too.

No worries though, as long as the fuel consumption remains low everything is working just fine. BMW's are a bit quirky this way, it's "normal" for them.

_______________________

This teaches me a lesson, NEVER change stuff after only one diagnostic, monitor it over a few weeks to see if the error is "real" or fake. Sometimes cars stand for too long, give errors when they are driven again, sometimes a bad batch of fuel or old fuel or even a bit of moisture in the fuel, sometimes an oil change cures things, sometimes they just need some good runs on the highway to blow out the cobwebs from granny driving.

All of this stuff can cause diagnostic errors that go away after some good driving on the highway and a few clean batches of fuel or oil.

Diagnostic errors are usually only about 50% accurate, do not waste your money till you are 100% sure an item has actually genuinely failed.

Thanks Doc!!

Should the consumption of 13.3-13.8L/100km be acceptable as the norm, then we are very happy!!

We will test it again in a few weeks, if that is ok by you and then see if the VANOS still shows on codes...

I will just refrain from "granny driving" as you put it... shouldn't be to hard.

How often should one add fuel system cleaner to your tank and which is the better one to use?

Why is it better to use it on a full tank than adding it to a tank with, say only 20 litres of fuel in it? (like full antibiotics course right?)

Thanks again!

 

[rick540]

You wouldn't need fuel system cleaner more than once a year.

I add it to a full tank as it absorbs moisture from the whole tank and cleans the fuel level sender unit as well + it cleans for a whole tank.

Brand.... All much of a muchness, they are all solvents, I use anything from Wynns that states O2 sensor safe.