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12blkgrayRS · 03-09-2018, 02:50 PM

I have an LFX with over 80k miles that is driving me insane. First the SEL come on after I bought it, the dealer (idiots) say the HUD is the problem (it originally wasn't working, bad unit). Uh NO it's not!! They never fixed it. I diagnosed myself and found a bad MAF sensor.
I then installed the CAI I had on my previous 12 Camaro that saw a lot of track duty. SEL's , misfires, lean condition pop up. Predominantly, P0300.
Bought a tool to check the coils, some were weak some were, just OK. the engines idles low and rough. thought it had an air leak somewhere. checked the CAI, and the intake. nothing. weird. So I removed the CaI and reinstalled the stock intake. Ran a little smoother, but on heaver throttle sometimes, the eng light will flash about 10 times. then go out. then after 50 miles stays on. Check my scanner, P0300, multiple misfires. Now I am suspecting, carbon in the heads/valves, injectors, and/or coils. With the current mileage I am betting on the injectors mostly. I ordered new coils anyway. hell just refresh what I can.
NOW, the eng temp too high turning A/c off in the dash comes on...OMG!!
OK, it seems the thermostat is staying open. engine never gets higher than 160. which is another reason the car is running horribly. This engine likes heat, the cooler temps freak out the electronics. weird things happen.
So that's next I guess to replace the tstat and fluid. But other than that the car runs really well. I have to let it sit and warm up to about 110 before I drive off. So the dash thing doesn't come on.
doesn't really come on during the warmer days. Just when it's cool and the engine cannot get over 147 degrees. So this is in progress. I know a lot of you are having this same issue. this is what I found so far. replacing coils tonight or this weekend. Will report if any change. Also changed to shell super to help clean the valves and fuel system/injectors. Seems to have a little more power and running a tad smoother. probably a lot of years from the previous owner with a lot of cheap/bad gas.
Also, ran a full tank of Lucas fuel system cleaner. that also seems to have helped. So it IS running better, but the underlying issues still remain at idle.

03-09-2018, 02:50 PM	#1
12blkgrayRS Drives: 2012 Camaro RS 2LT 6spd man Join Date: Aug 2013 Location: Dickinson, Texas Posts: 535	Service eng lights, rough idle, cooling warning lights I have an LFX with over 80k miles that is driving me insane. First the SEL come on after I bought it, the dealer (idiots) say the HUD is the problem (it originally wasn't working, bad unit). Uh NO it's not!! They never fixed it. I diagnosed myself and found a bad MAF sensor. I then installed the CAI I had on my previous 12 Camaro that saw a lot of track duty. SEL's , misfires, lean condition pop up. Predominantly, P0300. Bought a tool to check the coils, some were weak some were, just OK. the engines idles low and rough. thought it had an air leak somewhere. checked the CAI, and the intake. nothing. weird. So I removed the CaI and reinstalled the stock intake. Ran a little smoother, but on heaver throttle sometimes, the eng light will flash about 10 times. then go out. then after 50 miles stays on. Check my scanner, P0300, multiple misfires. Now I am suspecting, carbon in the heads/valves, injectors, and/or coils. With the current mileage I am betting on the injectors mostly. I ordered new coils anyway. hell just refresh what I can. NOW, the eng temp too high turning A/c off in the dash comes on...OMG!! OK, it seems the thermostat is staying open. engine never gets higher than 160. which is another reason the car is running horribly. This engine likes heat, the cooler temps freak out the electronics. weird things happen. So that's next I guess to replace the tstat and fluid. But other than that the car runs really well. I have to let it sit and warm up to about 110 before I drive off. So the dash thing doesn't come on. doesn't really come on during the warmer days. Just when it's cool and the engine cannot get over 147 degrees. So this is in progress. I know a lot of you are having this same issue. this is what I found so far. replacing coils tonight or this weekend. Will report if any change. Also changed to shell super to help clean the valves and fuel system/injectors. Seems to have a little more power and running a tad smoother. probably a lot of years from the previous owner with a lot of cheap/bad gas. Also, ran a full tank of Lucas fuel system cleaner. that also seems to have helped. So it IS running better, but the underlying issues still remain at idle.