hey scotty this is my first time asking a question love your channel I've got a 2005 pontiac vibe with a 186k miles she has just crossed over she's got a 1.8 liter 4 cylinder 16 valve engine. She currently has a bad exhaust and my mechanic at autoconcepts is a very nice mechanic he showed me and took me to the back the whole things gotta go that there were cracks inside the exhaust it self now it is causing a vibration i can feel it but here is the thing since I've been putting in 89 octane in the vehicle the vibration has been minimized not gone because its bad of course but minimized more livable and i know you already did a video about premium gasoline but in this case could it actually be helping my old worn out car i've asked a couple of my buddies of mine showed them what is going on when i used to put 87 octane in the gasoline the engine oil would always look dirty so i could never read it correctly but since adding 89 octane the oil has became more clear and readable to my eye's and some of my buddies' think it has to deal with less blow by going on inside the engine any help would be appreciated she is still running nice and strong though fyi
If the vibration you're feeling is related to carbon build up, higher octane will reduce that, because the fuel doesn't detonate before the spark plug ignites it. Built up carbon can increase the compression ratio and prematurely ignite fuel, causing knocking or pinging, which can present itself as vibrations.
Blow-by is blow-by, it's caused by piston ring wear and the already slightly imperfect seal the piston rings make. The only way I could possibly see that improving is if the majority of your blow-by is being caused by faulty ignition timing due to carbon build-up, which is causing the combustion cycle to proceed too early. That, and the combination of the still-increasing pressure from the compression stroke could be over-pressurizing the combustion chambers and forcing gas around the rings, hence the pinging noise most people hear and the rough operation. Get a borescope and look in your spark plug holes for carbon.
if it is related to carbon build up how come when i put 2 full bottles of techron fuel sytem cleaner into the gas tank it still vibrates could it be that if its worse then i think it is my mechanic might have to fully do it him self because i don't think it could be the igintion because its idling right around where it should be 900 rpms when its cold about 1500 then then drops back down once it has warmed up because i've poured several diffrent kinds of cleaners in there when i was using 87 so i'm wondering if he really needs just carbon clean it him self and try and get rid of all that carbon since the 1 owner before me i bet never carboned cleaned that engine causing me greif with the exhaust and all that
The bottles you put in your tank don't typically do a whole lot in the combuation chambers, they mainly clean the injectors. There are videos on YouTube of tests. You can enhance their cleaning power somewhat by putting it in the tank when the tank level is lower. A professional mechanic can carbon clean an engine without disassembling it if that's what the issue is. He should be able to tell you why it's actually doing it, before he does the service, if he's a quality mechanic.
alright thats good to note thank you because i'm just trying to sort all this out since i don't want my mother to to know so once i get a job and actually able to tell him my self and when i get my job actualyl be able to pay for the carbon cleaning surface because i was telling my mother if we want that car to last forever since its an old little worn out a to be car you know without going in debt to a car payment we have to understand what fluids are going into that engine because i've already got her to stop going to delta sonic to stop putting the cheap free 5k mile oil in and stick with what the engine is designed for 5w-30 full synthetic since valvoline will only charge 34$ since its a 1.8liter engine and only takes 3.9 quarts of it so i'm just trying to make small improvements to the car since i'm more sensitive to what kind of sounds vibrations are going on since since my family is a bit skeptical about what i'm doing to the vehicles i sit in
The grade of fuel you use has nothing to do with blow by, or worn out piston rings.
