How to pass the emissions test

[Snork]

Well my car got back from the mechanic after getting a bunch of stuff including a thermostat and a new radiator. Basically the engine is running like new now. The reason i resorted to a mechanic was cause the car was not passing emissions. After all this it still does not, thought it works a lot better. The mechanic said that the cats heat up so they're at least decent. He then suggested i put a injection cleaning additive in and change to oil to try passing emissions. Is there anything else I can do to the car to help it pass? It's very dissappointing right now, because it runs like a brand new car, but still gets a big black R on the inspection. What are some tricks you guys used to pass emissions?

[Robin-535im]

What are some tricks you guys used to pass emissions?

A friend of mine went to a local engine shop and bought a few gallons of pure ethanol ( I think... ) and diluted the gas with it until his 2000 chevy v8 just barely ran. Passed with flying colors.

[attack eagle]

I paid the guy an extra $30 under the table... suddenly my emission output matched exactly an unmolested newer car there ;)

[Sam-Son]

pay off the mechanic

[Snork]

I just paid him 740 dollars, if that's not paying him off, I don't know what is. But seriously, he's a really nice guy and is very professional. Maybe I need to find a crooked mechanic... I mean how did my e28 pass inspection? That thing was running rich like nobody's business, the mechanic took it to some inspection place and it passed.

But I think emissions is something the guys can't really fake. I mean they can overlook some safety issues if they are so inclined, but unless I actually knew someone who was actively substituting cars to pass emissions, that seems like a bad option. I don't want to insult my good mechanic by bribing him.
The ethanol idea sounds pretty good though... Anything else? Anyone have problems passing emissions and then passed it without cheating somehow?

[repenttokyo]

move to Quebec, land of zero emissions tests.

[e34.535i.sport]

I don't know how but my 535i (1990) has the lowest emmisions i've heard of...Over here we're allowed up to 1200ppm (parts per million) of carbon and mine recently passed with 39ppm!

I don't know if this works but some people fill up with high grade petrol, put in an engine additive and take it on a good long blast on the motorway... I done it the day before mine went in. Anythings worth a shot. Good luck.

[Snork]

move to Quebec, land of zero emissions tests.
I can live in your house then, eh?

[Sam-Son]

seriously ask your mechanic how you can get your car to pass. maybe he might get the idea of passing it for you or maybe he'll suggest somethin serious

[Dave M]

I can live in your house then, eh?

Eh, I resemble that comment. Mass-hole ;)

Dave

[Qube]

Good thread. Mine JUST passed with a CO % of 0.28 out of 0.28. I'll keep her through the winter and consider the Z4/TT again when the snow starts to melt.

[Snork]

Well it's kind of the opposite for me, cause I just got the car to where I want it after 4 months. All it needs now to be excellent is a/c and some exterior miscellany. In the worst case, the cats are too weak and there's another 4-600 dollars right there, but i'd rather dilute it with ethanol and give a gas station an extra 30 dollars, so I at least maintain some sense of this car being economically justified.

[Paul in NZ]

do a search..if i remember correctly fresh oil and if you present the car fresh from a hard drive (ie at proper operating temperature)you will have your best shot

[uscharalph]

This may be elementary, but was the car warm when it was tested?

[repenttokyo]

I can live in your house then, eh?

sure, until you get on your feet :D

[bsell]

Well my car got back from the mechanic after getting a bunch of stuff including a thermostat and a new radiator. Basically the engine is running like new now. The reason i resorted to a mechanic was cause the car was not passing emissions. After all this it still does not, thought it works a lot better. The mechanic said that the cats heat up so they're at least decent. He then suggested i put a injection cleaning additive in and change to oil to try passing emissions. Is there anything else I can do to the car to help it pass? It's very dissappointing right now, because it runs like a brand new car, but still gets a big black R on the inspection. What are some tricks you guys used to pass emissions?

I assume the 'bunch of stuff' is tune-up related? As in the right plugs, gapped correctly, solid ignition circuits, clean filters...

If the above is true, then I second the heartiest injector cleaning additive run through the engine at high speed/wide throttle openings. After that tank is done, change the oil and filter and fill up with good gas.

Reset the engine computer by disconnecting it for a while, then drive it on the highway to relearn the newly freshened engine settings with clean (non-petrol laden) oil.

If the above doesn't get you under the limit, then something might be going on with your injectors (dirty) or injection system (bad temp sensor, maf/air flow meter).

Brian

[Fred/Houston]

There's a product called "guarenteed to pass". It's $10/bottle at almost any auto store.
I failed in my E28, put a bottle in and it passed the next day.
Hth's
Fred/Houston

[cybereclipse]

hehe
this is totally OT, but the last time I went in for a smog check, the guy dropped my car off the dyno becuase he thought it was in park, but it was in reverse.

fixed the two stabalizer bars that he broke and gave me a free smog check along with a redeemer for another free smog check...
w00t!

[Barney Paull-Edwards]

I don't know how but my 535i (1990) has the lowest emmisions i've heard of...Over here we're allowed up to 1200ppm (parts per million) of carbon and mine recently passed with 39ppm!

I don't know if this works but some people fill up with high grade petrol, put in an engine additive and take it on a good long blast on the motorway... I done it the day before mine went in. Anythings worth a shot. Good luck.
Be careful, you might have a potential problem more important than bloody emissions! At 39ppm you`re running weak at idle,clean out the crank-case breathers and fuel filter otherwise its cracked seats and valves!

[Robin-535im]

... because it runs like a brand new car, but still gets a big black R on the inspection. What are some tricks you guys used to pass emissions?
Obviously something is wrong still - I had a 1980 320i with 300k miles and it passed with a new O2 sensor.

Check into why it isn't passing, CO, CO2, NOx, particulates,etc. That will point you to the problem.

Fuel / air ratio / O2 needs to be correct for it to pass, and the cats need to be really working, not just "hot".

There is no reason why it won't pass if all the emission components are working properly - so something is still wrong. See if you can upload the emissions test and post it - chances are good someone here can tell what it needs.

Good luck!

[Snork]

I actually did buy that "guaranteed to pass" stuff a few days ago and am now driving around with it. I bought two bottles just in case, to clean the injection system as much as possible with two tanks. About the oil change, the mechanic did mention this as a guaranteed way to get emissions at least partially down. Should i do this the day im trying to pass emissions or does it not matter if it's after a few days? All the filters and seals were new before, I replaced them myself. The mechanic said the car was running cold because it had a clogged radiator. Now he says the manifold gets up to 350 degrees and the cats are heating up now too. I'm being optimistic about the additive/fuel filter/new oil combination, cause the MAF is definitely working correctly and the engine has been entirely rebuilt over the summer by my friend and I. Maybe the noisy fuel pump has something to do with the emissions? Does anyone else have a burbling fuel pump?

[Paul in NZ]

The mechanic said the car was running cold because it had a clogged radiator.
a clogged radiator would make the car run HOT

[e34.535i.sport]

Be careful, you might have a potential problem more important than bloody emissions! At 39ppm you`re running weak at idle,clean out the crank-case breathers and fuel filter otherwise its cracked seats and valves!

Barney: Sorry i've missed this thread for a while... You've got me worried now, will it defo be running weak? It seems to use an awful lot of fuel at idle... Fuel filter changed within the last 2000miles... What are these crank-case breathers - can i do this myself and is it a difficult job (excuse the ignorance i'm still learning!)?

going to do a search on it now...

[Snork]

a clogged radiator would make the car run HOT

See, that's what I would have thought too, right? But this mechanic says that in fact it can make it run too cold. And im inclined to trust him, because he's an actual bmw mechanic who works on e34s a lot and happens to drive an e34 himself.

[Jeff N.]

Guys around here swear by this trick but I can't say I've actually tried it.

Unplug one fuel injector; take test; plug in when you've passed.

[Snork]

Wouldn't a misfire make the car run even dirtier? I mean, if it's not burning up all the fuel, it would have worse emissions,

[bsell]

I actually did buy that "guaranteed to pass" stuff a few days ago and am now driving around with it. I bought two bottles just in case, to clean the injection system as much as possible with two tanks. About the oil change, the mechanic did mention this as a guaranteed way to get emissions at least partially down. Should i do this the day im trying to pass emissions or does it not matter if it's after a few days? All the filters and seals were new before, I replaced them myself. The mechanic said the car was running cold because it had a clogged radiator. Now he says the manifold gets up to 350 degrees and the cats are heating up now too. I'm being optimistic about the additive/fuel filter/new oil combination, cause the MAF is definitely working correctly and the engine has been entirely rebuilt over the summer by my friend and I. Maybe the noisy fuel pump has something to do with the emissions? Does anyone else have a burbling fuel pump?

Change the oil and filter after running the cleaners through the fuel system.

You said you rebuilt the engine recently. Does it blow blue smoke anytime? If you had an oil-burning issue, you would get uncontrolled hydrocarbon readings (very high) that the fuel injection system can't do anything about.

Brian

[Snork]

As far as I can tell, the engine burns absolutely no oil now. I would probably have to change the oil to tell for sure, but the level is always good and the exhaust doesn't smell like oil, it smells more like a soviet tractor. But the mechanic said his e34 smelled like that and passed emissions nonetheless.