Tailpipe Soot! Should I panic?

I'm just went through the 4 part YouTube series that the PCA put together on bore scoring. It's very good. They mention that drivers side tailpipe soot is a symptom that you might have an issue. Of course my car has this. Based on overall probability of cars that have it vs don't, what would you hypothesize on the chances that my car has scoring? The car has 60k miles. Very well maintained. Stored in winters - although I did drive it a few times this past winter. Could this buildup on the tailpipe be caused by something else? My initial thought of course is panic and I'm likely going to get a scope completed. I didn't scope during PPI. I've had the car 2 years and have put 5000 miles on it since purchase. Thanks for any advice in advance.

It would help to have information about the car, i.e., year, model, maintenance records. Before tearing into the engine, check out threads on a failing AOS. There are ways to check the health of the AOS. Check out threads on replacing the factory AOS with the UAOS.

Quotes source post: 18765072

I wouldnt panic. But you can do 2 things to see what you have going on inside your engine. 1. Start by testing your oil. Order a Speediagnotics oil testing kit thru LN and test your oil. Just make sure you have about 1k miles on the same oil. Consider getting their little pump as well to suck the oil into the test bottle. Their kit has a return box thats prepaid. Just sent a test in two Saturdays ago and got my results back on Wed. Called Lake on Thursday to review the results. Easy and cheap. The results will tell you what's in your oil as well as what it means for the bores, pistons, etc. 2. To definitively confirm bore scoring you have to scope your bores from the bottom. If you do this, make sure you have your indy see what's jn the sump as well as cut open the oil filter to see what's in it. Hope it helps.

My 99 driver's side bank (passenger side tail pipe) has more soot on it as compared to the other bank. I get my oil tested, and I'm not loosing sleep over it. I wouldn't worry too much about it. It's not like a sudden failure with bore scoring. I plan to just keep driving the car.

Quotes source post: 18765164

Same here! Except my passenger side tail pipe tends to have more soot on it, which would point to bank 1. Everyone always said that bank 2 tends to be the problem so who knows. My car consumes oil too at about 1qt per 600 miles, yet my brand new UOA from speediagnistix shows 0 issues. Heck, even my fuel dilution dropped from 1.39 to 0.52! I'd use good oil, change it often and drive more! 5k miles in 2 years is not enough IMHO, especially when they're so fun to drive!

ahhh yes, the impending doom emphasizing that your M96 WILL blow up, no matter what. I know of way more people with high mileage 996's that have never, ever had an issue! Could be a bad or failing O2 sensor, causing the bank to run rich. Or a funky cat. Leaky valve seal causing oil to leak into a cylinder and burning off. Possibly excessive timing. Have you changed the oil on a yearly basis? In other words, don't panic

If I were you, I would…. You Tube

Thanks for the advice. I think I'll get the oil tested to check out what's going on. The car is a 2003. 60K full service performed at 55K 2 years ago, and I did an oil change at like 59K last fall. The car has also had the IMS, RMS, clutch and flywheel completed like 3 years ago.

This may seem like a bad question but how clean is the inside of your exhaust supposed to be? Seriously, are the inside surfaces of a tailpipe shiny and bright? Cuz mine aren't. ( freak out...) as kids say, show me.

Our cars burn hydrocarbons. Guess what one of the results of combustion is? ... Carbon. Shocking, I know. So, soot in and of itself will happen. I think there must be guidance about uneven soot between the two sides, or an 'unnaturally' heavy amount; whatever that might be.

The passenger exhaust is where the oil smoke comes out when you blow a AOS, I would suspect its starting to leak if its really black fuzzy in the pipe. Not just micro layer of carbon. How old are your injectors? Do you run a occasional cleaner in the fuel? Rich running will do the same thing as at the AOS as far as carbon, My pet theory is a bunch of the bore score fails are due to tired injectors. Seen it too many times on motorbikes that are set too rich at the track.

Quotes source post: 18768659

By Tired do you mean leaky with too much fuel leading to wall wash?

I think running an injector cleaner that has a high PEA content is key regardless of the age of your injectors. My favorite it the Redline SI-1 that Lake Speed put me onto. Since we all love actual data rather than anecdotal stories here is an example of how beneficial it can be: In April 2021 I installed my UAOS and brand new Bosh OEM injectors. Below is a screen grab of subsequent UOA fuel dilution numbers. They were always in the "green" without excessive contamination but look at the significant decrease between the last 2 readings. Even though there was a small decrease trend happening, after running several bottles of the Redline stuff the number went from 1.39 to 0.52. In vast majority of cases I only run Shell 93 Top Tier gas.

Quotes source post: 18768785

Yep and its not unique to our cars, any engine can flush the cylinder walls with too much fuel and ruin rings, cylinder, pistons.. Worst thing is it can be a function of a load of bad fuel, I had a truck with < 12K miles on it foul injectors and the thing smoked like crazy on start or I would not have known it till it was too late. On the other hand my old jeep 4 cylinder had 250K on the original injectors..

OP - I have observed soot and moisture spewing as the cats heat and the over enriched engine burns excess fuel introduced on cold start is due to crap fuel being sold these days. Winter mixtures result in extra water and soot for me. Summer blends are much better from what I see. Ethanol is not our friend! Oil sampling, clean injectors and fuel trim awareness are your ally.