Failed Smog... twice

So I took it in for a smog late last December and it failed. Its a 95 325is with 146,xxx miles with slight lack of power on low end all thru to 3rd gear. Results below.

15mph rpm-1754, co2-14.30, 02-.72,
HC-max85,meas262, CO-max.50,meas.54, NO-max695,meas1016
25mph rpm-1872 co2-15..08, 02-.11,
HC-max50,meas98, CO-max.47,meas.13, NO-max717,meas136
Failed all miserably except NO and CO at 25mph. This was with oil not due for change (about 2000 miles on it) new air filter, premium gas, good coolant and warm engine. Although it was parked and off for about 10 min's before it was tested.

So replaced 02 sensor (looked like original when I pulled it) replaced plugs (had NGK's and appeared to have normal wear) replaced with OEM, pulled intake boot and checked for vacuum leaks all through out and cleaned throttle body with seafoam although I did not run seafoam thru intake manifold, topped off coolant, ran a full bottle of seafoam, new tank of gas, full bottle of guaranteed to pass, another tank of gas and with a 3rd fresh tank of gas. Drove it for about 30 minutes and pulled up to a different smog place. Waited for about 15 mins and kept engine running while waiting. Results below>>>

15mph rpm-1703, co2-13.9, o2-.8
HC-267,CO-.65,NO-1312 (same max as above)
25mph rpm-2815 co2-14.6, 02-.2
HC-101,CO-.31,NO-645 (same max as above)

Failed same areas with higher numbers second time and even the two areas that passed barely passed also with higher numbers. What the heck???
So, now planning on tearing out cooling system, redoing again myself, checking fuel injectors, and somehow testing the cat. Any input on checking or swapping anything else? Advice on how to check fuel injectors and cat? Any help is appreciated. Thanks. Oh and all new oil also is planned. Thanks.

Also forgot to mention, I did not notice until recently on cold starts or slightly warm starts the idle with rev up and down then up then down again and settle at appropriate rpms. Which leads me to believe there is an issue with fuel injectors or something affecting air fuel mixture.

this is the 2nd case of people using gtp with miserable results....

if it were *that* easy to pass inspection we wouldn't need technicians.....


the format you listed them is horrible, by the way....not very easy to understand.

i got it, though.

just have to decipher it now.....




but it looks like you have issues.....





df

ok, well it seems to me that the following should be done, regardless of whether or not it aids in passing inspection.

1- clean the icv
2- run seafoam through the intake (lots of diy's around)
3- change the fuel filter


you should also consider the possibility of the vanos failing, as there was another thread with high NOx as well.


your higher free O2 levels @ lower rpm are high, and the are a tad high @ higher rpm (like to see lower than 0.2%), so it is quite possible the cat is on its way out.




df

Icv-idle control valve? Better to clean or replace? Fuel filter on order and ill run seafoam thru intake.
I was most definitely hesitant on using gtp but read 50/50 good and bad reviews on it IRT using on bmw. Live and learn. Did expect it to be that easy but was using it as another measure to clean out as much carbon as possible. Do 1995 325is have vanos? That is one thing I am not smart about but I have the Bentley manual and I suppose I'll get to doing some homework. Sorry for the bad formatting and I appreciate the help. Ill keep updating as I get opportunity to work on the car. Busy work sched. Thanks again.

Well I currently have the intake manifold out. Already bought a fuel filter but guy at oreilly gave me the wrong one. Picked up some fuel injectors as well and I have the fuel rail pulled off. From the looks of the FI it seems they could be replaced. I tested the ignition coil packs and coils for vdc and ohms and those are all good. Did compression test and not all is good. From cylinder 1-6, in psi, 150, 130, 120, 150, 150, and a whopping 65. Ouch. So looks like I have other issues. One thing at a time I suppose.

This mechanic says this is something he's used for a very long time to help. He mentions it (Shopline solvent) at 3:32. He says an old German told him about it long long ago.

I was certain my son's '97 328is would fail last year and I took it to Larry's Automotive in North County (Vista, CA) last year and he took it to "his guy" and it magically barely passed. Larry's only works on BMW's and his 2 guys both drive E36s.

Now I'm back in Utah and my county just requires a safety inspection. Wahoo!

Appreciate the help. I've seen Scottie's videos before and he seems to know what he's talking about. It wouldn't hurt running some of that thru the tank.

Alright so I didn't replace fuel injectors with new ones simply because they're way more expensive than I can afford and also I don't want to pay a ton of money if that's not for sure the reason it's not passing smog. The ones I put in came from a well kept e36 that was used as a parts car by a buddy of mine. They certainly looked better than the ones that came out of my car. I cleaned the intake manifold with seafoam (had a ton of oil in it) pulled icv and cleaned that the best I could, checked all vacuum lines and cleaned them up as well as bet I could, didn't find any with damage. Cleaned the throttle body very thoroughly (also very dirty and oily) and tested wiring going to tps and icv and those are both good. Put everything back together, turned it over an after an initial rough start it smoothed out an purrs like a kitten. I noticed idle rpms are a little lower than they were before. Took it around the block a few times and runs smooth. Going to run some more seafoam or shop line (as mentioned above) check tire pressure and do a coolant flush. After that then ill take for a third test. Hopefully third time is a charm. Thanks for the help from you guys so far.

Hmmm, wondering if I should get new fuel filter (the right one) and swap before I test it again or just go for it...

i think that you have more important issues with the compression being 1/2 of the rest of the group. you also have 2 cylinders less than 10% of the rest of the group as well....


a leakdown test would be the best thing to do next.





df

^ That exactly. Quit throwing money at it until you diagnose that weak cylinder.

If you're going to have a prayer of passing emissions you're going to have to keep fuel out of that weak cylinder. You're going to get marginal combustion from that one which means your HC, CO, and NO levels are going to be high. If CA only did the sniffer and a CEL didn't matter I'd say unplug the connector from the injector for that cylinder and give it a go at the smog station. I think if you do that though you're going to get a misfire CEL.

At df- can you point me in right direction on getting info on how to do a leak down test?
At dcwright- I like your idea on disconnecting that fuel injector but i think your right in that it will pop the cel. I might try it just to test that theory.
At horn- I agree with you and df but I need it to pass smog so I can get tags. However I also realize that it may play a big part if not the only reason I'm not passing hence why I did a compression test in the first place. I'm just eliminating any and all possibilities before I dive into deeper repairs. Either way thanks to all for the input and help. Much appreciated.

Buy this:

http://www.harborfreight.com/cylinde...ter-94190.html

Follow directions.

Before you do the leakdown test you can try a wet compression test to see if the low cylinder is due to rings or valves. Repeat your compression test on the low cylinder the way you previously did it so that you've got a baseline reading. Then pour/squirt about 1 oz of motor oil into the cylinder through the spark plug hole. Give it 20-30 seconds to disperse and redo the compression test. If the readings come up significantly or to normal, then you have a piston ring issue and the motor oil has temporarily helped them seal. If the reading stays low then you have either a valve or a head gasket issue.
If it comes up rings, it might be carbon build up in the ring lands inhibiting them from sealing. This is a bit radical but at this point it either works or you're taking apart the engine anyway. Pour 2-3 ounces of Seafoam directly into the sparkplug hole of the low cylinder, and let it sit overnight. Put the spark plug back in and run the engine for 10-15 minutes including some medium rpm revving. You're going to get a crap load of smoke out the exhaust from both the motor oil from the wet test and the Seafoam so don't panic.
Shut the engine down and recheck compression. If it's still down, repeat the Seafoam direct treatment again overnight. If after 3 or 4 cycles of overnight Seafoam the compression hasn't come up, then you're done and it's time to open her up. If it does return to normal, change your oil, do all your other planned smog prep and give it another try at the smog station.

F'n awesome help, that's why I love this site. Thanks horn and dc. I'm gonna try and make it to harbor freight and do it all this week hopefully.

Do the wet compression test before buying the leak-down tester. May save yourself $40.

Will do.

if you do get the leakdown tester, be aware it needs compressed air to operate.




df

Yes I saw that when I looked up the harbor freight link. I'm hoping a gear head buddy of mine has the tester, I know he has air. Planning to do wet check tomm after work. Will post results.

So.... I planned on doing wet test and as directed I performed a standard compression test to establish a baseline and amazingly all cylinders passed with flying colors. From 1-6 150, 150, 150, 148, 150 and 150. Plus or minus 2 psi for all. I didn't think about it until know but I did that compression test before I tore everything out, cleaned it all up and put it back together. Either way it was a educating experience and thanks for the info. All to do know is wait for the right fuel filter which comes in tomm and have a go at the smog station again. Ill update again when results are in. I really hope it doesnt end up being the cat. Fingers crossed.

well, i hate to put it this way, but i doubt that you will pass. the fact that the compression readings went up is because the oil prevents the pressure from blowing past the rings...

which means the rings are worn, based upon the previous readings.

now, it is plausible that the test was done incorrectly the first time, which is why i *always* check the readings twice, with the fuel cut off. if the fuel was not cut off, and you ran the compression test and didn't disable the fuel, then the last cylinder could *maybe* have been washed, producing the resulting low reading.




df

Fuel was disabled both times by pulling fuses and no oil was put into spark plug hole prior to doing test. Didn't get that far. Was doing this to establish baseline prior to doing wet test.