E39 oxygen sensors (O2) ? What do you know?

[atlantiskiwi 73]

My car is massively missing in cylinder 123. The mechanic believes it's the O2 sensor? How many are there? 4 pre car? How much and where from? Really keen to hear from anyone who's had experience with this issue.

[allan 295]

Can't help with any practical experience with these sorry Pelican has Bosch and genuine listed

11781742050 oxy sensor before cat Bosh $91.00 Genuine $260.75 US Dollars

11781433940 sensor after cat Bosch $104.50 Genuine $260.75

Their are four in total two before and two after the cats. Would make sure that it is these before replacing as those prices it is not cheap. Best of luck

Edited December 20, 2014 by tim 325

[atlantiskiwi 73]

Thank you. Not sure what more i can do to be sure it's the issue? Swap the sensors around?

Can't help with any practical experience with these sorry Pelican has Bosch and genuine listed

11781742050 oxy sensor before cat Bosh $91.00 Genuine $260.75 US Dollars

11781433940 sensor after cat Bosch $104.50 Genuine $260.75

Their are four in total two before and two after the cats. Would make sure that it is these before replacing as those prices it is not cheap. Best of luck

[hotwire 352]

Get the mechanic to diagnose it properly. It sounds a very random statement to be stating that an 02 is suspect. An 02 sensor out is not going to cause the issue you allude to. The car needs scanning properly & monitoring live data to correctly diagnose.

[atlantiskiwi 73]

Thanks. I have been reading up online and it would seem it's just as likely to be a vacuum leak or MAF sensor as it is o2.

Get the mechanic to diagnose it properly. It sounds a very random statement to be stating that an 02 is suspect. An 02 sensor out is not going to cause the issue you allude to. The car needs scanning properly & monitoring live data to correctly diagnose.

[hotwire 352]

Hence my statement of getting it diagnosed properly. The times i have seen MAF & 02 sensors replaced by people because of codes recorded, only to later find a mechanical issue has put them outside their parameters. Sounds like they may be out of their depth to come up with the statement you quote. I would say it is quite likely vacuum issue.

[Ahmedsinc 414]

^^^^ Listen to this guy.

Step 1 - GET IT SCANNED

Step 2 - replace all likely causes of intake vacuum leaks. Rocker gasket, CCV, DISA valve, secondary air pump (if you're unlucky enough to have one) oil breather lines etc

Step 3 - If that hasn't solved it, then go for the obscure stuff - injector o-rings, manifold gasket, secondary air rail o-rings etc. Could also need the Vanos seals replaced too.

I spent about 4 months tracking an intake vacuum leak that appears to have been the rocker gasket. Replaced a bunch of stuff that was borderline as well. Admittedly I do have the ability to scan for codes

M54s are chronic for intake leaks, the first sign of trouble is the 227 & 228 fault codes triggering the engine check light (Lambda Control Tolerance Bank 1 & 2) Once the DME detects unmetered air it goes to a 'safe' fuel map, overfuelling the engine, leading to the fault codes.

Blaming it directly on the 02 probes suggests your monkey mechanic isn't familiar with these cars. Take it to Glenn @ Botany Motor Worx or BM Workshop for a proper diagnostic and take it from there

[Olaf 3317]

yes, +1. You need the codes. And a diagnosis from someone in the know. As others have said, more likely a vacuum leak; could well be time for your PCV system service.

If it is your O2 Sensors, here's a more reasonably priced selection https://www.fcpeuro.com/BMW-parts/530i/Oxygen-Sensor?year=2003&e=180&m=20&page=1 though as noted, a duff O2 is unlikely to cause a misfire...

here's a video illustrating how much fun you can have changing out your O2. http://youtu.be/f70FrWhpUsc

cheers

PS - I jut did an O2 on my ovlov, using an O2 socket made the job easy - $20 well spent.

Edited December 20, 2014 by Olaf

[atlantiskiwi 73]

Thanks a lot guys! I really appreciate the help!!

^^^^ Listen to this guy.

Step 1 - GET IT SCANNED

Step 2 - replace all likely causes of intake vacuum leaks. Rocker gasket, CCV, DISA valve, secondary air pump (if you're unlucky enough to have one) oil breather lines etc

Step 3 - If that hasn't solved it, then go for the obscure stuff - injector o-rings, manifold gasket, secondary air rail o-rings etc. Could also need the Vanos seals replaced too.

I spent about 4 months tracking an intake vacuum leak that appears to have been the rocker gasket. Replaced a bunch of stuff that was borderline as well. Admittedly I do have the ability to scan for codes

M54s are chronic for intake leaks, the first sign of trouble is the 227 & 228 fault codes triggering the engine check light (Lambda Control Tolerance Bank 1 & 2) Once the DME detects unmetered air it goes to a 'safe' fuel map, overfuelling the engine, leading to the fault codes.

Blaming it directly on the 02 probes suggests your monkey mechanic isn't familiar with these cars. Take it to Glenn @ Botany Motor Worx or BM Workshop for a proper diagnostic and take it from there

[atlantiskiwi 73]

Cheers mate. I think I'm going to do O2 anyway and that spanner looks like the way to go!

yes, +1. You need the codes. And a diagnosis from someone in the know. As others have said, more likely a vacuum leak; could well be time for your PCV system service.

If it is your O2 Sensors, here's a more reasonably priced selection https://www.fcpeuro.com/BMW-parts/530i/Oxygen-Sensor?year=2003&e=180&m=20&page=1 though as noted, a duff O2 is unlikely to cause a misfire...

here's a video illustrating how much fun you can have changing out your O2.

cheers

PS - I jut did an O2 on my ovlov, using an O2 socket made the job easy - $20 well spent.

[Ahmedsinc 414]

Given the oxygen sensors are around $350 for the pair (via pelican parts, no idea what they'll cost locally) I strongly suggest running the car through a scan first. The likelihood is your Lambdas are fine, and it's a lot of cash to spill on parts that probably don't need replacing. Your money, your call of course, but a $50-60 scan from an experienced tech will accurately isolate the problem, instead of throwing money around chasing ghosts.

Good luck, hopefully you get your issue solved quicker than mine

[allan 295]

Interesting site https://www.fcpeuro.com/BMW-parts/530i/Oxygen-Sensor?year=2003&e=180&m=20&page=1 just check which currency they are in, NZ dollars or US makes a difference. Then the shipping on top of and if over the $400.00 you could have to add GST $$$$$$$.So why not spend 50-60 on a scan as Matt said could save you hundreds, give you peace of mind, a car to drive over the Christmas break not sitting in the garage.

[Olaf 3317]

Interesting site https://www.fcpeuro.com/BMW-parts/530i/Oxygen-Sensor?year=2003&e=180&m=20&page=1 just check which currency they are in, NZ dollars or US makes a difference. Then the shipping on top of and if over the $400.00 you could have to add GST $$$$$$$.So why not spend 50-60 on a scan as Matt said could save you hundreds, give you peace of mind, a car to drive over the Christmas break not sitting in the garage.

Hey Tim, I did say in the first instance - to get the codes. That is, scan it to see what code it's throwing.

As for FCP Euro - 2 front O2 sensors and 2 rears - Bosch OEM. USD269.80. $10 loyalty discount. Freight to NZ - USD28.21 via USPS. Checked out duty on whatsmyduty.org - close to the NZD60 threshold, but not over.

FWIW I bought my oxygen sensor wrench from Trade Tools - it/s 3/8 drive http://tradetools.co.nz/products/3031140

I should close with: Get the codes and diagnosis!

cheers

Edited December 21, 2014 by Olaf

[Allanw 1071]

I suspect you'll have misfire codes for the cylinders, and a code for an oxygen sensor, or fuel trim. Depending on the scanner used, you'll either have a generic code, or a BMW specific one.

If you have an O2 cell fault, a mechanic should know the O2 cell MAY not be at fault - If you're talking about the M54 in the 530i, it's most likely a vacuum leak - most common is the intake boot. Running too lean (because of the leak), gives an O2, or fuel trim fault.

[Olaf 3317]

here's an interesting blog post about diagnosing vacuum leaks, using OBD scanner and a can... that's certainly on-topic, and easy to understand...

http://blog.fcpeuro.com/2014/12/19/lean-faultsvacuum-leak-diagnosis-using-an-obd-ii-scanner/

Edited December 21, 2014 by Olaf

[atlantiskiwi 73]

Hi Allan, you certainly hit it in the head there.

I suspect you'll have misfire codes for the cylinders, and a code for an oxygen sensor, or fuel trim. Depending on the scanner used, you'll either have a generic code, or a BMW specific one.

If you have an O2 cell fault, a mechanic should know the O2 cell MAY not be at fault - If you're talking about the M54 in the 530i, it's most likely a vacuum leak - most common is the intake boot. Running too lean (because of the leak), gives an O2, or fuel trim fault.

[westy 614]

Needs more live data.,..

[Olaf 3317]

+1

any more info on this, or you gonna throw parts at it and hope?

[atlantiskiwi 73]

I took your advice and went to BM workshop for a full diagnostic. They were great as always! They concluded it was a dodgy fuel sender and that I had just run out of fuel....I little red faced I am. However the fuel gauge said 15l remaining. It has now been fixed and is reading correct. Apparently the injectors were showing low fuel readings which potentially confirms the diagnosis. Either way, full take of gas and full service/check over its running like a dream with the Bm guys saying it's an exceptionally tidy example.... With no other fault codes and car feeling as tight as your sister.

[atlantiskiwi 73]

However, I will be taking MAF sensor out and cleaning along with checking all my vacuum pipes and replacing the rocket cover gasket.

[Ahmedsinc 414]

All good preventative maintenance items mate. Really pleased it turned out to be a reasonably easy fix

P.S - I don't have a sister

[hotwire 352]

Great result. Bet you're glad you didn't take the first "mechanics" advice.

[atlantiskiwi 73]

Not by name

a great result!

you know my sister?

[atlantiskiwi 73]

I am indeed! But ever the optimist, I'm glad I took your advice!

Great result. Bet you're glad you didn't take the first "mechanics" advice.