Emissions help


#1

I need this '95 Galant with 140+KM to pass emissions in CA. First go around it failed the low RPM HC by one. It passed the high RPM HC by one two. This numbers are almost twice what they were 2 yrs (& 24KM) before. The car visibly smokes at idle.



Things I have done after the failed test;

I have changed the leaky valve cover gaskets, cleaned the throttle body, changed air filter, spark plugs and wires and put in 20-50 oil with one bottle of the thicker snake oil that is supposed to stop the smoking. The car smokes less at idle but you still see the smoke. Obviously I am not motivated to invest in more major engine repairs or a new engine, so I guess the question is; Can anything else be done to increase the chance of passing the test?


#2

High HC means the engine is running rich, or burning oil. If the smoke is black, it’s rich (or, misfiring).

The single, best, thing one can do, before going to an emissions test, is to change those high mileage spark plugs. Change the dirty air filter, also.

Did they say if it’s going into “closed loop” operation? If it doesn’t go closed loop, the engine coolant temperature sensor may not be accurate.


#3

HK has an interesting point. does this burn oil? if it burns oil, then the rings are suspect, but if it does NOT burn oil, then it would be a gas/air ratio problem.

how is the oil consumption?

has this ever had a timing belt replacement?

your car has an interference engine. if you havent had a new one put in its time.


#4

As mentioned I have changed the spark plugs and the air filter. The “old” ones did NOT look that bad. The smoke is blue (oil) and oil consumption is around 1qt/1KM. I know most say this is normal but then this car was not burning any oil 50KM ago! I have the timing belt done with the water-pump 40Km ago and have another 20KM or 18mths time on that one. I am not sure what the “close loop operation” is, the temp gauge acts normal, but I think that has no bearing on the question asked, so how would I know? The CEL is off and O2 sensors are also relatively new. And if anybody thinks a new cat converter will do give me estimates for rip-off pricing in Southern CA.


#5

Any chance of a vacuum leak somewhere which could be causing the ECM to go rich? This could be easily checked with a vacuum gauge.

What about the ignition timing? Has the timing belt or distributor been dinked with? Slightly retarded ignition timing has same effect as richening the fuel mixture.
If the timing is correct then maybe it could be advanced 3 or 4 degrees over normal until the test is passed. This has a tendency to lean burn it a bit.

Also, what color is the smoke?


#6

Well the timing was retarded. Because of high NOx and valve clatter under load. I guess I could advance it a bit and see what happens! The smartest way would be to have it done since I don’t have a gun and am just tinkering with listening and feel. Honestly I see whitish smoke but then the coolant and everything else checks OK, so I think is whitish blue and I am color blind as my wife would attest.


#7

“The smoke is blue (oil) and oil consumption is around 1qt/1KM.”

sounds like burnt rings.


#8

Thanks for all the replies. I did a pretest today with all the stuff that I had changed and everything was %40 less than before. This time I also let the car and cat converter warm-up before going in (last time they let the car sit on the lot for half a day and then just cranked and tested it). So I passed the final test and good to go for now.


#9

Passing the test or not, I think you need to proceed a bit further with this. High NOX and a rattle points to an EGR system fault; either clogged passageways or a defective part.
Retarding the timing will raise the HCs, lead to a slight loss of power and fuel economy, etc.

On the offchance the EGR problem is nothing more than sooted up passages you could try running a can of SeaFoam through the intake manifold and if this clears up the NOX, or more importantly the rattle problem, you could then advance the timing back up to what it’s supposed to be. Hope that helps.


#10

The rattle is long gone. This is after slight retarding and cleaning the throttle body with the spray and cloth. We are still looking for a better used car and don’t have much longterm faith in this one.


#11

They let it sit on the lot a half a day before doing an emissions test on a cold engine?! Almost any fool knows that the emissions test isn’t performed on a cold engine! These testers must not be any fool; but, something different.


#12

Straight 30 weight would stop the smoking. 20W50 will not. Catalytic converter change will bring the HC down. Cleaning the deposits off the intake valves would help reduce the oil burning by providing more space for the air to get into the cylinders, reducing the vacuum in the cylinders.