Hello all,I have a 1989 300e 165k miles, I took for Arizona emissions testing.Here are my results
my car standard
HC .88 1.60 pass
CO 9.23 15.00 pass
NOX 2.702.50 failed
In the past with other cars, if I failed NOX I would just replace the egr valve. I wish to do the same thing with this car, but I cant find it. I have looked everywhere. Can anyone advise me where to find the egr valve, or would sea foaming the engine work, or if there is anything else I should do to help pass NOX:? thanks in advance. I have already changed plugs and such.

 

Usually when you take the car to another shop other than the dealer they dont know to heat up the cats alot before the test. if you run the car and get the exhaust really hot you will probably pass. just to let you know. we get that alot here at the dealership because people go elsewhere then they come here and the car just needs to be hot enough

 

Hi,
NOX (Nitrogen Oxides) is a function of combustion temperature.
This temperature is controlled by EGR (Exhaust Gas Recirc) which by introducing CO2 and N2 (exhaist gas) rather than O2 reduces the amount of NOX generated.

Presumably the EGR valve is not opening fully or at the correct time in the cycle.

Location of valve is different on different engines but shouldn't be too difficult to locate once engine cover mouldings have been removed to give clear view of the manifolding.

One of the other forum members may know more about the specifics of the location.

Since you are only just in the fail zone a "warm test" may just put you on the correct side of the line. However this requires an interpretation of the regulations which is technically offside. The test should be cold.

Stuart.

 

I couldn't find an egr valve on this car (89 300e) so I took it down to a German repair shop. as opposed to taking the car and pretending to fix it & charging me. The owner advised that I put a gallon of 100% methanol into the tank, he directed me to a place to find. I did so and it passed. He explained that methanol burns very cleanly due to being about 112 octane. exhaust is contains more oxygen or somthing like that. I dont know if there will be any long term effects from using the methanol but it worked to perfection, and I'm sure it also cleaned my injectors. just a tip for someone else who maybe having trouble passing emissions

 

Neat way around the regulations.

Long term use of Methanol will wreck the engine.

Methanol is increasingly being used in Europe under the banner of Eco or Bio fuels since it can be made from vegetable matter and burns "cleaner" than gasoline. Usually blended with gasoline but engines are modified to accomodate use of these fuels.

Presumably once you go back to petrol you will not be meeting the regulations. Thats down to your conscience.

Would be surprised if your car doesn't have an EGR.

Stuart.