Diesel Emissions Test

[Cdub]

My NHC-250 went through the diesel emissions test today. This test is required by the State of New Jersey for any diesel truck that weight over 18,000 lb.

The results after three average tests were 0.526% and the state maximum is 55%. So she passed with flying colors………OOH RAH………!!!!

Cheers,

C’dub

 

[kcimb]

Do you mean .526 as in less than 1% of the allowable limit, or 52.6%?

 

[Cdub]

Re: RE: Diesel Emissions Test

Do you mean .526 as in less than 1% of the allowable limit, or 52.6%?

Just like I wrote..........0.526 %.............of allowable limit of 55%........


C'dub

 

[n1bnc]

Is there a scale vs age or something that allows older vehicles to "stink" more than current techonology?

 

[Jake0147]

RE: Re: RE: Diesel Emissions Test

That'll be an opacity test. It pretty much means that the base engine is in servicable condition, compression is at least decent, and the fuel settings are conservative enough that the engine can actually use all the juice you're putting into it, and most of the (engine related) maintenance items have been completed. It's not looking for specific gasses, but overall condition. It's a light and a receptor. The test is how much light from the light actually reaches the receptor when the whole thing is stuck in the exhaust pipe. Mostly it's to get the gross polluters off of the road. Not old trucks so much as the new trucks where the owner would rather live with a skip than drop what it takes to replace a single injector, eight grand on an engine because his air filter didn't seat right, new variable turbos that "stick" and many other common issues that tend to get left alone for economic reasons. It seems like a very big difference between the spec and the reading above, but the engine really doesn't have to be fifty percent shot to get fifty percent opacity. A dirty and somewhat restrictive air filter can take the same engine and make it flunk the same test.
I like it, it's a good test. Pretty much any old engine that's in "all right but not great" condition can pass it if the filters and oil changes are up to date, but no engine out there new or old can really pass it if you neglect basic maintenance. If you have to live with emissions testing (and I wish I could say that I didn't think it was necessary), but if you have to live with it, this one is (IMO) a good one to live with.

 

[WillWagner]

RE: Re: RE: Diesel Emissions Test

Opacity testing has nothing to do with the condition of the cylinders. You can have an engine that is worn out, and it will still pass on opacity. An opacity meter won't measure white or blue smoke. The only thing that it will measure is soot colored smoke...dark grey or black. C'dub, .526% is an incorrect reading, the guy didn't know what he was doing, or the machine wasn't calibrated correctly. Electronic engines aren't even that low. Not baggin' on ya, the reading you have is good for you, cause it showed up as very, very clean! Just don't be surprised if when you go back for another test, that you get a reading more in the 20-45% range. That is still a very good test result, Shoot, 54% for a NA engine is good! BTW, specs are 55% max for 1991 and older, 45% for later than 1991 except 2007, they are zero.