86 325e Failed Emmisions!

[BMW Punk]

Help!
My 86 325e Failed miserably on the Oxides of Nitrogen (NOX) portion of the emmisions test, 8.09 as opposed to 2.50.
The emmisions people say to replace the EGR valve, there is no EGR valve on this modle BMW.
Here are the symptoms, the car won't idle above 500rpm if it idles at all, prior to that the Idle was eratic.
I've been told to replace the Idle air speed valve to fix the emmisions problem, befor I drop $125 on that part I need some input.
Thanks Guys.

 

[epj3]

Replace your thermostat, engine temperature sensor (NOT the one for the gauges, the one for the ECU), and if that doesnt fix it - it's probably an induction problem (ie bad air flow meter, possibly bad oxygen sensor) bad idle control system - which i honestly doubt is causing the high NOX reading)

Could also be over-advanced timing. When was the last time the timing belt was replaced? More than likely the car is just dumping too much fuel into the cylinders.

I am pretty positive it's one of these three things:
-Cold start injector. basically a fuel injector that dumps extra fuel into the engine when it's 'cold' (before the thermostat opens)
-Thermostat (if it is stuck open, the car will ALWAYS be in "warm up mode")
-Temperature sensor (obviously this is how the ecu knows whenthe car is warmed up)

 

[BMW Punk]

Thanks!
The car has 190,000 miles !
Its about due for a new belt, thats gonna happen when I replace the head gasket, soon.
Since the temp gauge isn't working I was planning on replacing the temp sensor and the thermistat.
too many miles and all the little things that go wrong.

Hears a thought, anybody wanna buy the car?

 

[epj3]

Thanks!
The car has 190,000 miles !
Its about due for a new belt, thats gonna happen when I replace the head gasket, soon.
Since the temp gauge isn't working I was planning on replacing the temp sensor and the thermistat.
too many miles and all the little things that go wrong.

Hears a thought, anybody wanna buy the car?

190k is a lot of miles? Since when? Maybe on a new 3 series, but ETA's will run forever. Ask justin......

 

[BMW Punk]

195,318 Miles to be exact. I was hoping to get to 200,000 before I replaced the timing belt.
I bought the car really cheap used. The majority of the mileage is highway miles, The body is perfect, no rust Arizona car, the engine runs strongand the care handles great.
So far I've replaced the front ends rubber parts with high performance poly. and put in a new shifter assembly. other than that the car is pretty tight with a few electrical repairs needed.

 

[jrt67ss350]

I'm upwards of 290,000 now, and she still runs like she's brand new. There's still quite a bit of life left in that eta of yours if it has had regular oil changes.

I think Eric gave you some really good advice about where to start in troubleshooting the emissions problem.

 

[BLK318i]

I bought my 96 318i a month ago and smog laws here in California are strict now. I had the same problem you did. I passed everything but the 15mph emmissions for the same reason (NOX). I took the car to a friend and what he did was a "clean up". All he did was cleaned the combustion chambers. The car passed with flying colors after that and it only cost me $75 for the diagnostic and clean up.

 

[BMW Punk]

Ha hah ha!
All I needed was a $14 part, the airduct between the throtlebody and the mass air flow sensor. there was a huge crack on the underside of the damn thing!
Not only did it yake care of the emmisions problem but it also took care of the idling problem!
Just goes to show that major problems can be caused by vacume leaks.