Exhaust Smells Shitty

[JENNY!]

you gut your cat- it smells worse.

 

[KINGPIN33]

Why don't you pull your Spark Plugs to see how the car is running. Mine are black as hell b/c of oil or running rich... Not sure which one yet... But pull the plugs and check them! If your not running rich, then the plugs should be nice and clean with little to no carbon buildup.

 

[KINGPIN33]

Well, if the mixture varies even a little from what's correct and stays there for a certain time the O2 sensor will report that to the TCCS as a fault and should set one of two codes. It'll only do that if the igniton key has been cycled twice with the problem present both times. Maybe it's not a mixture problem after all. No way to tell without either measuring the exhaust stream or checking the O2 sensor signal. Based on no codes I'm going to go out on a limb and say it's not a mixture problem. The cat could be contaminated by some additive you put in the fuel or oil ie; the "seafoam syndrome". H2S is almost always caused by a rich mixture though. It's tough to know without doing some more digging. Run the engine at 2500 rpm for 10 minutes with the brake booster hose off and the O2 sensor unplugged. That'll drive the system lean and burn off anything that might be in the exhaust system or on the O2 sensor. It's an old trick used by emissions techs. Can't hurt anything to try.

Will that trick burn carbon and junk out of the combustion chamber? My spark plugs are pretty black colored. thanks.

 

[jetjock]

Will that trick burn carbon and junk out of the combustion chamber? My spark plugs are pretty black colored. thanks.

Examining plugs is one way to tell if the engine is running lean or rich. In fact you're right, I should've told the OP to check his plugs since he has no ther way to measure mixture. If he's rich enough to foul the cat his plugs will look like yours.

Plugs in an engine running lean will have bright white insulators so this will clean the plugs but you'd have to do it for a long time to clean any CC carbon. Not a good idea. This isn't going to help you anyway. You're treating the symptom and not the disease. You need to find out why the engine is either burning oil or running rich. Start with a compression test.

 

[KINGPIN33]

Examining plugs is one way to tell if the engine is running lean or rich. In fact you're right, I should've told the OP to check his plugs since he has no ther way to measure mixture. If he's rich enough to foul the cat his plugs will look like yours.

Plugs in an engine running lean will have bright white insulators so this will clean the plugs but you'd have to do it for a long time to clean any CC carbon. Not a good idea. This isn't going to help you anyway. You're treating the symptom and not the disease. You need to find out why the engine is either burning oil or running rich. Start with a compression test.

I did a compression test awhile ago and the numbers were pretty high. 175-180... this could result from my block and head being shaved twice. Also I believe carbon build up will give me screwy numbers that are too high! I'm running very THICK oil too 20W-50 + LUCAS. I've been battling hard start issues too and after cleaning the plugs with some engine degreaser, I noticed the car started on the first try when cold. I seriously got some engine problem... worn valve guides? (i've got new valve stem seals/BHG job done not too long ago/no codes/car is completely stock)
arrr...

 

[Aaron J Williams]

If you run the car with an intake leak that big won't it burn the exhaust valves?

 

[jetjock]

No, not at that power setting and load. That they will is a common misconception. Kingpin: You left that motor open and exposed over a winter? You didn't protect the bores? And you're using a 20-50 and Lucas in Toronto? In winter?

 

[KINGPIN33]

No, not at that power setting and load. That they will is a common misconception. Kingpin: You left that motor open and exposed over a winter? You didn't protect the bores? And you're using a 20-50 and Lucas in Toronto? In winter?

When I say I left it opened. I mean I poured some oil down each combustion chamber and coated each of the cylinder walls with oil to make sure it didn't rust. I also put the cylinder head on loosely over the winter when I was at school. The car was inside the garage too. HOWEVER, I did leave it for a period where minor rust was developing on the block surface (2 weeks) I used a lot of brake cleaner and carb cleaner (2 cans worth) on the pistions to clean out the carbon. I hope that didn't destroy the bores? I mean, I have pretty good compression from my test , but it could be from carbon buildup...

Yes I should be slapped for using that thick of oil in this cold... but i'm not stupid to start the car at negative degree celcius weather. I will start the car up today and the weather in the MIDDLE of December here in Toronto Canada is 8-4 degrees celcius! lol... The coldest I've started that car up with that thick of oil would be 0 degrees celcius. When looking at the stock oil pressure guage, at idle, the pressure is pass the middle mark and just under the next mark after. Do you think its too much oil pressure?

Thanks man.

 

[Doward]

KnifeArtist:

Odd, I would think the stock pressure-based oil cooler system would prevent going much over 40 psi.

Anywho, bad cat = rotten egg smell, in my experience. Caused by H2S, which JJ pointed out.

Black plugs = running rich. It'll cause your exhaust to smell funky (not that you should be sniffing that stuff) and cause a mayhem of other problems.

just my .02
Even at idle, a leak anywhere after the AFM can cause problems. Check *EVERYTHING*

Pressurize your intake tract, to find every single tiny leak you can.

Kingpin: Oil will usually show up as 'wet' on the plugs, as generally it will leak whether or not the car is running - valve stem seals are usually the culprit, assuming no major blowby.