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-   -   1996 328is CA smog check fail (http://www.bimmerfest.com/forums/showthread.php?t=655347)

foaxaca 10-31-2012 09:04 PM

1996 328is CA smog check fail
 
Daughter's 328is just failed the much hated California smog check. The numbers are as follows:

HC (PPM) NO (PPM)
MAX AVE MEAS MAX AVE MEAS
15 mph 54 9 78 430 67 446
25 mph 37 6 37 717 62 192

Basically failed at 15 mph for HC and NO. Going to start by changing out O2 sensors and plugs. Just changed oil a week ago. No CEL codes. Any other suggestions?

drivinfaster 10-31-2012 09:20 PM

how many miles??

it's rather odd for hc & nox to be high at the same time, but i would look at the basic maintenance items like plugs and filters.

i'd also check the egr operation for restriction/carbon build up.

o2s would be a a good idea as well depending on the mileage.

seafoam would also be suggested, again, as a maintenance.





df

foaxaca 11-01-2012 07:52 AM

Mileage is just below 178K. Bought it used about 4-5 years ago and it looked very well maintained but no idea if O2 sensors have been changed. I haven't changed them out. Will do new plugs, O2's. Just changed oil. I'm suspecting the catalytic converter was not as hot as possible. Any suggestions on how to check the EGR system? Is it a valve that needs checking/cleaning? I've done a bit of searching and most of the references to it are for BMW diesel engines. The posts to talk about lots of carbon that can build up and has to be chipped off. Is that what our gasoline engines experience also?

drivinfaster 11-01-2012 09:13 PM

i believe only the obd2 engines came with egr systems. it's a way to reduce nox without relying on the cat so much to do so.

i would do the maintenance stuff first, then retest and see how it fares. it's rather close. a seafoam and a roadblast should also be beneficial.

good luck with it and let us know how you fared.



df

foaxaca 11-02-2012 11:55 AM

I'm shopping for new O2 sensors and getting some confusing info. How many does this car (1996 328is) have? 2 or 4? Are they both connected to the exhaust manifold or to the catalytic converter? Or is it one in each location?

drivinfaster 11-02-2012 07:44 PM

96 is obd2 in north america, so there are 4. bank1 (cyls 1-3) sensor 1 (pre-cat), bank2 (cyls 4-6) sensor 1 (also pre-cat), and bank1 sensor2 (post cat), as well as bank2 sensor2.

the sensor2's are only there to check the cat performance, and will not affect the way the car runs. at all. period amen.



hope this helps.



df

bmw-mania 11-06-2012 09:05 AM

holyhell...

Stop.
Oil change first.. run a half quart low.
Acetone supplement to fuel tank.

Oh.. and READ THIS
http://www.bimmerfest.com/forums/sho...d.php?t=648574

foaxaca 11-06-2012 09:55 AM

Hahaha! Thanks for the link. All I've done so far is change the oil and filter, left it a half-quart low, inspect the EGR valve (it was very clean), order new plugs and O2 sensors (have no idea when they may have been changed by previous owner or if ever changed) and plan to Seafoam the engine. Check engine light bulb was out so pulled the cluster and changed that one this weekend and cleared the code for that. Car was probably not run at full operating temp for the test it failed and tires pressure not checked so I'll make sure they are to max pressure. I think we are getting winter gasoline in California now but will have to check. Wondering what an acetone supplement would be. Is there a commercial product that is sold as an additive?

bmw-mania 11-06-2012 10:03 AM

:D

Nope.. re-read.

100% Acetone reduces the surface tension of fuel. (lowers HC)
Cleanup systems take a while to get out of the system... may impede accurate readings.

Please keep track of what you do, and post results.

foaxaca 11-06-2012 10:07 AM

Thanks for the help. Will post progress and results.

foaxaca 11-11-2012 08:16 PM

Here's the latest... Changed our spark plugs, replaced with Bosch Platinum +4 plugs and replaced pre-cat O2 sensors with Walker Products replacements. Drove the car about 1/3 mile to local Chevron station, filled it up with 91 octane and added a can of SeaFoam to the gas tank. Car ran smoothly getting there. Left the station and pushed it up to around 60 and before I got back home, stopped at a light and noticed that it was idling roughly and below it's normal idling RPM's. Just as I was making the final turn into my street, CEL came on. Damn! Pulled it into the garage, pulled out my Peake tool and read several O2 sensor adaptation and cylinder misfire codes. I'm thinking if these were the wrong O2 sensors I would have noticed something right away. Is there some re-adaptation that needs to take place when you change out O2 sensors that may cause error codes before that happens? Cleared the codes and re-started the car and it ran smoothly and no CEL. Didn't run it on the street though. Any hints?

ZeGerman 11-11-2012 08:55 PM

Quote:

Originally Posted by foaxaca (Post 7189372)
Here's the latest... Changed our spark plugs, replaced with Bosch Platinum +4 plugs...

Well I can tell you right off the bat that the plugs you installed are basically the worst ones available for these engines, and are known to cause misfires. You may have other issues, but the Bosch Platinum +4 plugs have a documented history of being terrible. The plugs to get are the NGK BKR6EK - just the standard copper version. They're cheap and work very well.

http://img1.mlstatic.com/frete-grati...502_082012.jpg

foaxaca 11-11-2012 10:36 PM

Ugh! Got the same reply on anothe forum. Better order other ones... Kept the old ones (which were two-electrode type) and will reinstall in the meantime.

foaxaca 11-12-2012 09:09 AM

Here is the O2 sensor I purchased: http://www.fcpeuro.com/products/bmw-...lker-250-24810

I reinstalled the old plugs and started the car up again. It idled a bit rough for a bit, smoothed out and then started to idle rough again. Idle RPM's about 25% lower than normal. No check engine light at any time. Could this be the SeaFoam causing this or am I looking at another set of O2 sensors? The car had no issues before other than not passing smog check. I've already combed for vacuum leaks recently and found a couple along with replacing a CCV hose that was cracked. Car has been running fine since.

Things seem to be getting worse instead of better!

foaxaca 11-12-2012 09:38 AM

Bonehead Maneuver!!
 
Embarassed to admit that after reading another post and looking in the Bentley manual it suddenly occurred to me that I may have flipped the leads for the O2 sensors and plugged them in backwards. Sure enough, switched them and the car idles perfectly. Will still change out the old plugs with identical replacements and forget the +4's for now based on what other posters are telling me.

bmw-mania 11-12-2012 09:45 AM

Let us know how it goes! :D

drivinfaster 11-12-2012 06:18 PM

Quote:

Originally Posted by bmw-mania (Post 7179020)
:D

Nope.. re-read.

100% Acetone reduces the surface tension of fuel. (lowers HC)
Cleanup systems take a while to get out of the system... may impede accurate readings.

Please keep track of what you do, and post results.

acetone is fairly inexpensive, and, if it were such a great additive, i would figure it would already be something that would be added to the fuel.

i have serious doubts as to the effectiveness of this thing longterm, as well as the accuracy of the testimonials of people that have used this product as a way to increasae fuel economy and reduce emissions.

now, if exxon, bp, shell, et al, were to publish studies thatverified these claims, then i would believe it. however, at this point it sounds no better than a chemical turbonator.


and a proper running engine should have no issues with hc, or any other of the emissions...


edit:
http://neubranderinc.com/blog/2007/0...soline-busted/








df

ZeGerman 11-12-2012 07:33 PM

Quote:

Originally Posted by foaxaca (Post 7190124)
Embarassed to admit that after reading another post and looking in the Bentley manual it suddenly occurred to me that I may have flipped the leads for the O2 sensors and plugged them in backwards. Sure enough, switched them and the car idles perfectly. Will still change out the old plugs with identical replacements and forget the +4's for now based on what other posters are telling me.

Glad you seem to have got it sorted! Thanks for posting back and letting us know.

blingin96 11-12-2012 09:24 PM

Did you pass the smog test? I have a CEL and I'm going through the same process you are.
My o2's are on the way and I already changed the plugs. Next up.. Oil change and cross my fingers on the test.

foaxaca 11-13-2012 04:29 PM

Have you read the CEL codes? I haven't retested yet. Waiting to run through the tank of gas with SeaFoam in it and to change out the old plugs with the non +4 plugs. Will post results.

blingin96 11-14-2012 09:37 AM

My codes point to the cats. Which is why I want to do the o2's first. It's cheaper. I really don't want to do cats if I don't have to 261500 on my ODO.
She has been a great car. I JUST finished rebuilding the cooling system. New water pump, tank, hoses, thermostat, and I replaced the plastic thermostat housing to the metal one. All seems good.
Now it's on to this smog issue.

foaxaca 11-14-2012 10:47 AM

By codes do you mean post-cat O2 sensors showing an issue? I don't think there is any other reading that is related to the function of the cats. That's what those O2 sensors are for. It may mean changing those also. They don't affect the functioning of the cats. I have looked into the possibility of having to replace the cats and there are some cheaper alternatives. One thing to make sure of (I'm sure you've heard this already) is to make sure the exhaust is up to regular operating temp for the test. Run it on the freeway for 20 minutes and keep it running right up to the test. The tester may even let you keep it running onto the dyno. I've even read to wrap the cats temporarily in insulating heat shield material to get the temp even higher to increase their efficiency. Only about 179k on the odometer of my daughter's car so determined to get it to pass. Also heard about a product called CRC "Guaranteed to Pass" which is another fuel additive that seems to get good reviews from others facing the same issues. Oil change with 20-50W to reduce splash on cylinder walls is another recommendation I've heard to keep HC numbers down.

drivinfaster 11-14-2012 06:34 PM

all of that goes out the window with obd2 cars as they do running tests of the cat. and in order for the light to be turned on, the system has to see a fault twice in a row with the same parameters in order to turn the light on.

with 261k on it, i'd say the cats are pretty much done...

i do not put much faith in products like 'gtp', though. seafoam yes, as a maintenance treatment to remove carbon and such, but not much more than that. there are no 'magic potions' that will make the car run properly if there is a fault with a sensor or other component.



df

foaxaca 11-14-2012 07:57 PM

I agree. Any faults that cause a CEL have to be addressed, the CEL reset and the car run for 100-150 miles at certain speeds so that the car's computer gives a clear reading to the test equipment. Learned that last year with my son's 2002 325ci. Changed out the O2 sensors and reset the CEL, took it to get retested and tech told us it was too soon since the CEL was reset. You can look up "BMW drive cycle" for more info. It looked impossible to go through the whole thing so we just drove it through a full tank of fuel and then retested and it passed.

IndianBob 11-15-2012 11:30 PM

I thought the CEL was set after three starts, but what do I know? :-0


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