Camshaft sensor code despite new sensor

[guppy]

Hi folks,
Long time reader, first time poster...and first time new owner I just picked up a 97 Z3 1.9 with 100,000kms on it in the dark green. The car just doesn't look like any 20 year old car I've ever seen! Drives fantastic and now that we finally have some sun after the weeks of flooding in our area, it's a joy to have on the road.

Anyway, onto the reason for the post. When I viewed the car, it had a CEL so I asked the owner to sort that. He had the codes read and there was only one - P0340, camshaft sensor. So the owner ordered the part and had it replaced. CEL gone, car passed emissions test in Ontario no problem (CEL on is instant fail in Ont). This was a few days ago. Fast forward to now and I've got the CEL...guess what the code is? Yep, P0340. That's the only code. The car runs fine...idle is a bit lumpy but it revs well and goes like the clappers (well, for a small motor!).

I've searched for a while here and other places and the only conclusion I can come up with is it's a bad new sensor/non-BMW part. I'm fine with replacing the sensor again now that it's my problem if that's really what it is.

Any other ideas from the hive mind?

Cheers

Dave

[rf900rkw]

Do you have a recording scope that you can hook to the CMP that links to the DME so it can record serval seconds of data when a code sets? Me neither. So what you do is inspect the wiring and connectors for fraying or damage, then replace the sensor again.

[guppy]

LOL! Awesome reply Randy.... Yeah, I think that's on the cards. From my research it's "did you get the BMW sensor? Nope...then get the BMW sensor" Rinse and repeat.

Thx!

Dave

[fmcfad01]

this is probably anecdotal, but when I got a camshaft code on my S54, it was because the maf was going bad. Cleaning it worked for some time, then I just replaced the MAF and didn't have to deal with it. Love when you get a code for one thing, replace it to no avail, then find that it's something totally unrelated.

[Vintage42]

When my 1.9 spun without starting one morning, I removed the cam sensor based on forum advice, and it started. So I replaced the sensor and all has been well for the past two years. But i did use an OE BMW sensor.

[Tim95M3]

I used to replace aftermarket sensors all the time when I worked at an independent... Never had issues with nice OEM sensors.

[guppy]

Just to close the loop on this in case anyone else had the same problem. Replacing the sensor again with the OE part from BMW solved the problem. In fact, as soon as we started the car, the code cleared...didn't even need to clear it with a tool! Lesson learned - use genuine parts for sensors.

[wallball]

Darn I should have read this post before I purchased an aftermarket sensor for $36.95, installed it and found that the car ran worse than when I had the old "broken" sensor in the car. I could tell immediately that the car wasn't running on full power. Bloody hell. Plus the code p0340 popped right up after one engine start/off/start cycle. Darn again! I just ordered a BMW sensor for $136.00 and will report on my findings. Hope that fixes it.

[wallball]

Replaced the after market sensor with an OEM BMW one and all is well. Don't buy anything but BMW for this application. Will contact the supplier and discuss the issue with them so they can be aware of it. Thanks again, all, for the passing along of knowledge.

[LannVouivre]

Ah, I once tried replacing my MAF (dropped it and one of the hot wires ceased to exist) with a Bremi unit in a misguided attempt to give them the benefit of a doubt. Began having the fuel trims correct to 27% added fuel when the engine was warm and the hood was closed. I chased the problem for a long time before borrowing the MAF off my fiance's 525 and verifying the MAF was trash.

Ordered the Hyundai branded MAF and problems stopped.

[gmushial]

Ah, I once tried replacing my MAF (dropped it and one of the hot wires ceased to exist) with a Bremi unit in a misguided attempt to give them the benefit of a doubt. Began having the fuel trims correct to 27% added fuel when the engine was warm and the hood was closed. I chased the problem for a long time before borrowing the MAF off my fiance's 525 and verifying the MAF was trash.

Ordered the Hyundai branded MAF and problems stopped.

On the otherhand, I'm running a $30 totally generic MAF off eBay, have been for the last 50k miles, with zero issues... when we had this ongoing discussion 4 or 5 years ago about oem vs oe I decided to try to test the theory: so bought the cheapest one I could find, swapped it for the existing bimmer branded one - and found no difference... I think the problem is: all new parts have a probability of being out of spec, bimmer branded ones and otherwise, just that the bimmer ones have a smaller probability of such... but this is not to say that others can't be found that are likewise.

[wallball]

On the otherhand, I'm running a $30 totally generic MAF off eBay, have been for the last 50k miles, with zero issues... when we had this ongoing discussion 4 or 5 years ago about oem vs oe I decided to try to test the theory: so bought the cheapest one I could find, swapped it for the existing bimmer branded one - and found no difference... I think the problem is: all new parts have a probability of being out of spec, bimmer branded ones and otherwise, just that the bimmer ones have a smaller probability of such... but this is not to say that others can't be found that are likewise.

I always try after-market first, and until now, all of the parts (quite a few) have worked well, and at least look like OEM, sometimes better. I wrote to the parts supplier but haven't heard back yet about what they think, i.e. do they get a lot of returns on this item. In this case the OEM and AF parts had very slightly different wire configs WRT strain relief: that was the only obvious difference. It was a FAF brand, which I have used in the past successfully, so I'm pretty curious about the above-postings and other's experiences with this sensor. Regards, Don.

- - - Updated - - -

Do you have a recording scope that you can hook to the CMP that links to the DME so it can record serval seconds of data when a code sets? Me neither. So what you do is inspect the wiring and connectors for fraying or damage, then replace the sensor again.

and I love Randy's post, "...then replace the sensor again." Hah!

[LannVouivre]

On the otherhand, I'm running a $30 totally generic MAF off eBay, have been for the last 50k miles, with zero issues... when we had this ongoing discussion 4 or 5 years ago about oem vs oe I decided to try to test the theory: so bought the cheapest one I could find, swapped it for the existing bimmer branded one - and found no difference... I think the problem is: all new parts have a probability of being out of spec, bimmer branded ones and otherwise, just that the bimmer ones have a smaller probability of such... but this is not to say that others can't be found that are likewise.

I think that the biggest differences are quality of components used to make the parts, such as cheaper plastic with a shorter lifespan, and bigger tolerances for component parts allowing shittier parts through quality control.

For example, at work I cut plastic sheets into rectangular sections for me to then engrave to make tags. After I cut the pieces, I compare the pieces and measure them with my digital caliper to decide if they meet my standards. Sometimes the safety saw will make little deviations in the sizes and quality of cuts, and since I set everything up manually and I'm the one who pulls the saw down the cuts every single cut I do is at least a tiny bit different from the others. I also have to improvise to check the straightness and squareness of the parts I guide the plastic sheets through because the foreman doesn't want to get me a square, so whenever I try to adjust anything it's a major PITA. The foreman also dislikes me changing anything ever, so...but anyway, I have to go through the crap I've cut and make sure it's good enough to go on $25,000 control panels for Chevron etc.

Sometimes I end up with horrifying amounts of mistakes and wasted material, so I can understand why some companies may be lax with QC.

[BimmerBreaker]

Someone posted in another thread that OEM vs. OE parts are made on the same production line, all parts are tested at the end but the OE have a stricter quality control. So the ones that dont meet OE quality standards get thrown in an OEM box.

[LannVouivre]

Someone posted in another thread that OEM vs. OE parts are made on the same production line, all parts are tested at the end but the OE have a stricter quality control. So the ones that dont meet OE quality standards get thrown in an OEM box.

It's always a gamble. I picked up an AISIN oil pump for my Vibe; it was $50+ cheaper than the Toyota version and had the "TOYOTA" lettering ground off.