Announcement

Collapse
No announcement yet.

Emissions help needed

Collapse
X
 
  • Filter
  • Time
  • Show
Clear All
new posts

    Emissions help needed

    So I picked up an 86 325es about 2 weeks ago.

    The first Sunday I spent my day replacing the timing belt, tensioner, thermostat, water pump, v-belts, air filter, and all the coolant hoses.

    All that went well, although it took a bit longer than I expected. It wasn't difficult though.

    On the next Monday I had an issue with coolant overflowing and a bit of overheating at idle. After looking into it, I discovered that I hadn't quite bled the system properly.

    Wednesday I spent my evening by jacking up the front of the car, adding coolant to the reservoir, and trying to bleed the system. Heater was running during this time. Heater output is warm, but not as hot as I was expecting.

    Thursday - Tried to run it through emissions. Got the car up to operating temp before taking it in. The car did not overheat, but was getting warm, so while I waited in line I had to shut it down when I was waiting.

    I ran the test on it and it failed on NOx. I don't recall exact numbers but they were something similar to this:

    HC - 1.3, Max allowable - 1.6
    CO - 9.43, Max Allowable - 15.0
    NOx - 6.4, Max Allowable - 2.5

    I was somewhat expecting this so I took it to my parent's place to do work.

    I figured I NEEDED to find out why my fans weren't kicking on, so I tried to bleed the system again to no avail. The fan did kick on when jumpered on both high and low settings, but not through the switches.

    New fan switches were ordered as well as a coolant temp sensor for the ecu. Plugs were removed and showed a nice brown color, but were Bosch Platinum +4's, so I replaced them with standard NGK plugs. I then ran about half a can of Seafoam through the intake and dumped the rest into the gas tank.

    When the sensor and switches arrived at the parts store I picked them up and installed them. When I removed the CTS, some, but not much, coolant came out of the hole. When I removed the upper fan switch (Low speed on this car - is this correct placement, or does it not matter?) NO coolant came out. When I replaced the lower fan switch, some, but barely any came out. Coolant was added, front end jacked up, heater on, and attempted to bleed the system, but was unsuccessful as far as I can tell.

    I then ran it through emissions again and the numbers were as follows:

    HC - .7, max allowable 1.60 grams per mile
    CO - 11.07, max allowable 15.0 grams per mile
    NOx - 3.38, max allowable 2.50 grams per mile

    Next day I went back to the drawing board and jumpered the low speed fan switch so I could keep it running during the wait in line, tried to bleed the coolant of air again - which I don't think worked, richened up the mixture screw on the AFM about a half a turn.

    I replaced the vacuum hose from the FPR to the intake manifold as it looked pretty bad. I then sprayed around every place I could think of looking for other vacuum leaks, but found none.

    I attempted to test the O2 sensor as outlined in the Bentley manual, but I'm not sure I did it right because my results were as follows:

    Volts would continuously drop and keep going into the negative. I could introduce a vacuum leak (open oil filler cap), the reading would drop faster, but come back up a bit before dropping again. The reading would increase in both cases if I revved the engine.

    I then took the car down for testing again. I waited in line for about 30-45 minutes and didn't need to shut the car off at all while waiting. These were my results after 3 runs on the rollers (I guess the kid didn't know how to drive the car or something):

    HC - .65, max allowable 1.60
    CO - 13.39, max allowable 15.00
    NOx - 3.07, max allowable 2.50


    I ran a bottle of Guaranteed to Pass through it last week and filled up last night with 89. Took it over to get tested this morning as the place is only a few miles away. I did NOT preheat the cat or anything of that nature. Just started it and drove it over.

    The idiot testing it was a good 8+ inches shorter than me and didn't move the seat. As a result he ran the car on the dyno not once, not twice, but 5 times before getting a good test result.

    The result was

    HC - .57
    CO - 12.21
    NOx - 2.9

    I am so damn close to passing that it is irritating. Help me out guys.

    I'm not really sure what to do now other than a cat and/or O2 sensor. Any ideas?

    #2
    High NO2 is a bad cat.
    Originally posted by Gruelius
    and i do not know what bugg brakes are.

    Comment


      #3
      Kinda what I figured. Was hoping since I'm so close that there was something else I could do.

      Comment


        #4
        At the point of time, effort that you have put into getting this car to pass...if your throw on a new cat you will pass with no issues. Like stated earlier high NO2 points @ your cat. Have you run it really hard right before you take it to be tested, get the cats nice and hot?

        Comment


          #5
          The first three times I did get the cats nice and hot.

          Any suggestions on what cat to do as far as stock vs. Universal?

          Comment


            #6


            That is if your willing to put that much $$$ into it. You could find a used set (verified that they passed on the car they are coming off of) too for a bit cheaper. Try your local pick-n-pull.
            Last edited by HR2L; 04-16-2011, 03:49 PM.

            Comment


              #7
              Originally posted by HR2L View Post
              http://www.turnermotorsport.com/p-32...ate-legal.aspx

              That is if your willing to put that much $$$ into it. You could find a used set (verified that they passed on the car they are coming off of) too for a bit cheaper. Try your local pick-n-pull.
              If I'm doing a stock cat I can get one for 280 shipped new. Was just wondering if any of these universal cats a worth a damn.

              Was also considering trying an O2 sensor to see what that does.

              Comment


                #8
                Originally posted by KenC View Post
                High NO2 is a bad cat.
                Nope. Just a by product of lean running or high combustion temps.

                If its not properly bled a hot air pocket or boiling coolant in the area can fool the coolant temp sensor to improperly richen/lean out the mix. Work on getting the car to bleed and heat correctly.



                Any properly tuned car can pass the smog rollers without a cat...

                You are probably dealing with a intake or vacuum leak post AFM based on how your numbers look. Did they give you O2 also?

                Comment


                  #9
                  Originally posted by GDA View Post
                  Nope. Just a by product of lean running or high combustion temps.

                  If its not properly bled a hot air pocket or boiling coolant in the area can fool the coolant temp sensor to improperly richen/lean out the mix. Work on getting the car to bleed and heat correctly.



                  Any properly tuned car can pass the smog rollers without a cat...

                  You are probably dealing with a intake or vacuum leak post AFM based on how your numbers look. Did they give you O2 also?

                  Well I've been a bit concerned about my cooling system. I replaced the t-stat when I did the timing belt. I tested it in boiling water and it opened.

                  The t-stat is a 180. According to the meat thermometer I used to measure temp of the water it started opening at about that. There has been a time or two where I've questioned whether its opening now though.

                  I'm thinking of swapping it out with a 160 degree t-stat though.

                  Other thought is that maybe my radiator is partially clogged because it seems that only the passenger side really gets hot. The driver side will heat up, but only after a long time.

                  I have another radiator, but not sure of its condition.

                  Low speed fan switch is by-passed to run with ignition on because I can never seem to get the damn things to kick on. Both switches are new.

                  The gauge kinda works. I believe I have a bad ground or SI board because when I fill my fuel tank, the gauge shoots right up to the red. I can usually hit it and it will drop. Also, it will twitch when I use the turn signals.

                  On normal use, the needle climbs all the way up incredibly fast, but again, I can tap it and it will drop immediately back to half or below half.

                  I'm pretty sure the fan clutch is shot so I'm probably going to order a new one, but don't see how that could make that much of a difference.

                  They don't give us any O2 readings here unfortunately.

                  Comment


                    #10
                    How old is the water pump?

                    A good water pump and fan clutch would be the ticket since its running hot.

                    Coolant temps of just 20 deg higher equate to combustion temps 3x or more higher than normal... that is most likely part of your DME mixture (fuel map is set to richen the mix to keep it cooler and battle preignition) and NOx problem

                    Comment


                      #11
                      Water pump is new. It was replaced on the 4th of this month with the timing belt.

                      Comment


                        #12
                        Thought about something... i ran 87 Oct in it on the first three tries. Now running 89. Perhaps 91 would help me with that combustion temps and that .4 of nox

                        Comment


                          #13
                          It will help, albeit very small.

                          Big ticket is to get the cooling system working properly... and a properly running fan clutch dramatically aids cooling at idle and speeds below 20 mph so that could also be hurting your performance at the smog station.

                          Comment


                            #14
                            new fan clutch has been ordered.

                            Comment

                            Working...
                            X