scansinboy

I have to take the old emissions test, this will be the second time. My rings are worn and as such, I burn a bit of oil. Short of doing a rebuild of the whole engine to fix that problem, my question is this:
Is it better to take an emissions test with the engine cold or warmed up?

I was told that part of the purpose of the catalytic converter is to burn off the excess oil that seeps through the rings and gets into the exhaust. So it would make sense to have it nice and hot, am I right? Or am I completely way off?

Also, the mechanic stated/hinted (off the record, of course) that he would be curious to know what the results would be if I went in with the PCV valve disconnected. Would that make a difference? Is it legal? The emissions guys never check under the hood...

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soccerchamp76

The catalytic convertor works best under hot conditions. During the emissions test, they have signs to keep your engine running at idle while you wait because you have lower emissions with a hot engine.

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Nimisys

emissions test are performed ona vehicle at operating temperature.

cat converters help clean up the remaining CO, HC and NOx in the exhast.

PCV takes the blow by gasses in the crankcase (such as those going by your worn rings) and allows them to be sucked back into the intake, to be burned off.

disconnecting the psv valve is technically illegaly, and if at an honest smog station will result in a failure, for a deactived/tampered emission control device.

A smog consists of visual check of emissions equipment and a functional testing of them.

GetRdone

If you want to get around them, "legally" do this. Run your tank to empty and fill up with about a 1/4 or less tank of good fuel (mid to premium, but no race gas ). Then add about 4-6 bottles of HEET fuel system additive....its basically alcohol and some stabilizers. By doing this you will get pretty bad mileage till the tank runs out, but will burn VERY clean (its moslty alcohol!). Ive done it a coulple of times with my cars and it works 95% of the time.

poof

Catalytic converters "trim" off the HC, Nox, CO2 emissions that were not taken care of by normal emission sytem components controlled by the computer. Like the O2 sensor (unless heated), the cat needs some run time as it works best when hot. The five gas analyzer used for emmission inpections are just that, gas analyzers. Oil smoke is a measure of particulates (deisel engines use opacity meters for particulates and don't create HC and CO as much as a gas engine as thier is no restriction in the intake, no butterfly, so oil burners use a different test) and not measured by a gas analyzer, it won't see the disgusting smoke. The problem from this point is low compression caused by the components you mentioned above. Those components will cause high HC by allowing unburned, or partially burned fuel to get to the end of the tailpipe. High HC can also show high CO.

Put in new plugs, dump some <a href="http://www.seafoamsales.com/">seafoam</a> into the throttle body, or vacuum line from the booster depending on your injection system until you can kill the engine, (read the directions) dump the other half can into the crankcase. This will free up stuck rings, lifters. Go for a drive. Get the engine to operating temperature, don't idle in the line, You might fail anyway, but then you can apply for a waiver depending on the state in which you live. Tell us the year of the vehicle, and the state you are in. (I mean't geograpical location). All might not be lost, as I said, burning oil produces particulates that the gas analyzer won't care about. Please see my credentials in the "who are professional mechanics list" and private message me with your readouts. We can go from there.

BTW, HEET say's it is safe for your cat. I just don't understand the point of using it if your fuel lines are not frozen. Do the Sea Foam, and lets talk privately. I can always try to help a member!

belkins

Dump in a quart of 50W oil too. It will help with the blow by past the rings.

Poof mentions Seafoam which I've never heard of but his credentials speak for themselves. I'd listen to him!

Poof, I've got a question though. You mention that Seafoam can free up stuck rings and lifters. If he already has blowby can't that possibly make the situation worse since it will allow more oil flow by getting rid of sludge and stuff?

poof

Good point Belkins. Some of the sludge removed by the treatment could make things looser. Hopefully though, the hydraulic lifters will work more effectively at valve timing, and make better combustion than what scansinboy now has.

The inherent constant reversal of keystone style rings will wear the ring boss toward the inside of the piston. If their is substantial carbon buildup there (in the groove) cleaning that out could make the rings go toward the piston. Proper ring end gap will prevent that, and the rings will go back to scraping as they are supposed to do. Typical high mileage cylinder taper will create the blow by into the crankcase and the bottom line is, rebuild time.

Bottom line as mechanics say, "Pay me now, or pay me later". If you can squeeze out another year, you're set. But, ah the caveat, you are buying, and wasting, quarts of oil, polluting the air, and in some states, you the individual cannot sell a car that won't pass emissions.

I still need to know the make, model, year of the car, and the state it is located.

One more thing, dumping alchohol into the system is one of the four common destroyers of a cat.

pocon1

Ohh, seafoam. I discovered the joys of it this year. Half a can into the brake booster line of my 2002 wrx turned it into spy hunter for about 10 minutes burning off the crap. it was really embarrasing pulling out of the neighborhood, and everytime I downshifted the smoke built up even more. The car felt pretty good though. On my Acura I went out to a local park to do it. But that car was not a problem. So little smoke was emitted from the top end flush. Good Acura. 70,000 miles and nice and clean.

Poof, I have a question. For my Subaru (horizontally opposed Boxer engine) with the brake booster pulling off one side of the engine, will it circulate through all of the vacuum passages or will it just clean one side? Some people on my car forum said to use the egr or tps (I forget which), but it is buried under the throttle body and intercooler, and you have to pull the intercooler to get to it. When I cleaned the throttle body, I went through the coolant sensor on top of the throttle body so I could reach the plate and passage. Thanks for your advice.

poof

I am glad I could help a member.

Hmmm, aftercooled? WRX with muchos HP! Nice choice my friend, Later (after Christmas, or any other holiday you might enjoy while looking at the Menorah)