IS350 one spark plug black other 5 ok does anybody know why?
#1
Lexus Champion
Thread Starter
IS350 spark plug black does anybody know why?
IS350 spark plug is black does any know why? performance is lacking.
Last edited by MWIS350; 06-06-15 at 10:48 PM.
#3
Could be bad gas. I see this a lot at my dealer because there are a lot of shady gas stations on the reservation near my work. I would assume you wouldn't be dumb enough to accidentally put diesel in it...
#5
Black spark plugs are a result of rich running not lean, lean plugs are white due to running hotter. Rich plugs are carbon fouled which means too much fuel is going into that one cylinder. Not sure why though, perhaps the injector is no spraying correctly?
#6
Lexus Test Driver
That plug looks fine. Now if that black soot was on the tip/center electrode, that'd be a sign of the cylinder running rich and it would be concerning if it was doing that only on a single cylinder.
If you're at 100,000 miles or more and haven't replaced the plugs, replace them.
If you're at 100,000 miles or more and haven't replaced the plugs, replace them.
Last edited by NickTee; 06-06-15 at 10:24 PM.
#7
Lexus Champion
Thread Starter
I also check other plug and all are black. Just order new MAF sensor hope it help.
Trending Topics
#8
Lexus Champion
Thread Starter
That plug looks fine. Now if that black soot was on the tip/center electrode, that'd be a sign of the cylinder running rich and it would be concerning if it was doing that only on a single cylinder.
If you're at 100,000 miles or more and haven't replaced the plugs, replace them.
If you're at 100,000 miles or more and haven't replaced the plugs, replace them.
#9
Lexus Test Driver
#10
Lexus Champion
Thread Starter
thank for information. How about new ECT - Engine Cooling Temperature Sensor will that help if car feel lacking performance?
#11
Lexus Test Driver
The first thing you need to do is verify that there's an actual abnormality in performance versus what you perceive to be an abnormality. Whether you have access to a track, a dyno, or just straight up try 0-60 times and compare them to what the car would normally run.
#12
Ah I didn't see the plug picture before. That looks fine. If you don't have a check engine light on you most likely don't have any problems. Also the weather is getting warmer which could result in a little less performance.
#14
Lexus Champion
Thread Starter
Car lack performance 0-60. I might try 1/4 miles time at track. Test drive wife IS250 and her car seem smoother good power to get around.