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Showing results for tags 'missfire'.
Found 12 results
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I did a search here for it but came up empty. Last week, my Check Engine Light came on briefly while on the highway. Just before and after that I noticed a reduced lack of response to giving it more throttle. I had a local guy pull the CEL code and said it came up as #7 Cylinder Misfire. I'm at 55,000 miles and am off warranty. The truck is a '14 with a 5.3. Any suggestions, or thoughts how serious this may be ?
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I purchased a 2021 Silverado Crew Cab High Country 4WD about 4 months ago from Watson Chevrolet in Tucson Arizona. Within week of driving the truck I began noticing some pretty strange sporadic things happening. I started video taping the issues when I could to document what was happening. Ticking noise coming from the engine when cold starting, sporadically have hourglass on stereo saying “loading” it would continue until the engine was turned off and back on then it was OK. “Park Assist” Error message sporadically popping up while driving down the road, Horn honking (three short honks) for no reason while sitting in traffic at a red light. At 900 miles I reached out to the dealer and told them these concerns and issues I was experiencing. The service manager explain to me “the truck has a lot of technology and it just needs to learn your driving habits, you just need to keep driving it” At 11,000 and 3 months after purchasing I get the loud lifter noise, “Service parking brake”message, “steering assist reduced” message, “Service ESC light” and “check engine light” I drove it into the other dealership located in Tucson (O’Reilly Chevrolet), they keep the truck for about three weeks and “replace lifters on one bank and 1 bent push rod” and tell me that they couldn’t duplicate any of the other issues however they did a firmware upgrade and everything should be fine. One week after getting the truck back (11500 miles) I get another check engine light, Keep in mind I can still hear the lifters ticking when starting it first thing in the morning. I take back to the dealer after a week of a being in the shop, They tell me “The check engine light was because there was multiple cylinder misfire and it was the opposite bank from the lifters they replaced” however they can’t duplicate the problem so there’s nothing they can do. They admitted that the computer had logged over 200 misfires on one cylinder and that’s what made the check engine light turned on, then they go on to tell me they can’t duplicate the problem so there’s nothing they can do. I asked them about the ticking noise when starting and the tell me “that’s normal, it’s not lifter noise you’re hearing, it’s the new technology fuel pumps GM is using that’s making that noise” Other issue I have had is the rotors on all four wheels at times will turn blue and discolored as if the brakes and her have been completely overheated. But it’s not the entire rotor It’s only the center inch of all rotors. The inside edge and outside edges look normal. I have a purchased over 11 band new (Ford, Chevy, Dodge, Toyota) Trucks in the past 30 years this is by far the worst freaking vehicle I have ever purchased. -
I have a 2000 Silverado 2500 6.0 that is having some hesitation/cutting out on acceleration. It’s weird it seems like if you ease into the throttle it doesn’t cut out but if you mash on the gas it acts like it wants to die. It does it in park and in drive. First noticed it when I was pulling my boat out of the lake and I could barely make it up the boat ramp, it was spitting in sputtering until it eventually seems like it cleared up and started going normal. I replaced the spark plugs, spark plug wires, fuel pump, fuel filter, ran seafoam through the gas, and change the air filter but it seems to not of helped there’s also no check engine light. What could be the issue, thanks!
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I have a 2015 GMC Sierra 1500 All-Terrain, BlackBear Tuned, V4 Delete, run Mid-grade fuel. This is the second time its happened within a few months, different cylinder but the same side the dealer repaired. I should still be under warranty for this fix too but can anyone else relate to this issue? Is it the tune? could the V4 disabled make the problem worse? I guess when my warranty is up and it fails again I heard there is an AFM delete you can install that should fix this issue.
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2014 Silverado, 3.42 gears, 5.3L, 75K miles Truck has all the current maintenance. Even recently had throttle body cleaned and relearned, MAF replaced, air filter new, and fuel induction treatment Notice after hard drive pulling or spirited drive on the freeway, when I exit the highway on off ramp, say sitting at a red light, when I take off the truck makes it thru first gear smooth, but literally falls flat in 2nd or 3rd. Feels like a misfire, or lack of fuel, or something. odd thing is, power thru it, next stop light, no issues, drives fine. Dealer cannot replicate, no one has any ideas. Been to 3 dealers and they are all stumped. Any ideas guys? Thank you PS: I know the trucks can be laggy with the Torque and fuel management system, but this behavior is new within the last 15K -
Hows it going, any help and advice is VERY much appreciated. 2000 Silverado 4.8 vortec 1500 4wd. I have been trying to figure this truck out for months, shakes at all rpms although certain rpms are worse than others(the missfire) I have replaced intake manifold gaskets, double and triple checked vaccum system for leaks doing smoke tests (no vaccum leaks), replaced pcv valve, thoroughly cleaned injectors, confirmed everything fuel wise is working properly, new fuel filter. Still shaking badly. The other day I had a great idea, I waited until it got dark outside and decided to run the engine and look under the hood. Sure enough, I noticed sparking (shorting out) happening on pretty much all of the coils. The sparking is COMPLETELY random and there is never a consistent spark, for example one moment coils for cyl# 2,5,1,7 will be sparking, the next moment they wont and others will, and sometimes they look like they arent sparking at all, Also may mention that the drivers side of the motor seems to be sparking more often but it does indeed happen on both sides. It seems to spark a little more frequently when you spike the throttle. All i have replaced in the ignition system is the spark plugs, and made no difference at all. All of the coils are producing a spark at the spark plug. I have checked the common grounds to each ignition coil (plug on the top of the coil) and they all were grounded. Truck has 240k miles. If someone could please help me I would really appreciate it I feel like im SO close to fixing this thing and is my only car right now and need to figure it out. Thanks -
This is driving me insane, 2000 Silverado 4.8 vortec has codes for random missfire and apparently all cylinders are missing about the same amount of times according to the Chevy dealer. I noticed a small intake manifold gasket leak (truck would barely run on cold cold starts till it warmed up) so I replaced the intake manifold gaskets and did multiple smoke tests confirming no air leaks... I have checked each individual spark plug for spark, they all do. Had fuel pressure within spec. Removed all injector connectors 1 at a time and they all made a big difference (all are working in pretty sure).. I replaced pcv valve and fuel filter to be safe. I also plugged up the egr port in the manifold to see if I have a leaky egr system still nothing. The codes the truck also gave are map and maf sensor codes, although the codes were pulled before I changed the intake manifold gaskets so I'm assuming the manifold leak may have caused these sensors to throw codes but I am going to swap sensors with another truck tomorrow. Truck does have 240k on it, but I know this problem is fixable although I have nearly lost all hope as of this point. Any advice is much appreciated, thanks
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This is driving me insane, 2000 Silverado 4.8 vortec has codes for random missfire and apparently all cylinders are missing about the same amount of times according to the Chevy dealer. I noticed a small intake manifold gasket leak (truck would barely run on cold cold starts till it warmed up) so I replaced the intake manifold gaskets and did multiple smoke tests confirming no air leaks... I have checked each individual spark plug for spark, they all do. Had fuel pressure within spec. Removed all injector connectors 1 at a time and they all made a big difference (all are working in pretty sure).. I replaced pcv valve and fuel filter to be safe. I also plugged up the egr port in the manifold to see if I have a leaky egr system still nothing. The codes the truck also gave are map and maf sensor codes, although the codes were pulled before I changed the intake manifold gaskets so I'm assuming the manifold leak may have caused these sensors to throw codes but I am going to swap sensors with another truck tomorrow. Truck does have 240k on it, but I know this problem is fixable although I have nearly lost all hope as of this point. Any advice is much appreciated, thanks
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I'm getting a P0300 thrown every 10 days or so and I'm trying to track it down. Haven't thrown any money at it yet. This is on my 2004 Tahoe Z71 5.3L Flex engine with 161K miles. The image is the missfire data from my Maxidas code reader. I don't know why cylinder 6 and 7 are red (maybe the Maxidas software was written for the 6 cylinder?). The missfire data is almost always at idle. Over 1000 RPMs, missfires are rare. The photo shows 1400 RPMs, because I was goosing the throttle and the misfire is a counter over 15 seconds. If you leave the engine speed high, the misfires go almost to zero. Truck has plenty of power, decent idle. Tests I've tried... Moved fuel injector from cylinder 5 to 2 Moved ignition wire from cylinder 5 to 2 Moved coil pack from cylinder 5 to 2 Moved spark plug from cylinder 5 to 2 Measure 19 In.Hg vacuum at the manifold Ran a crank position relearn from my Maxidas Could not confirm the misfire with a timing light, looked like good strobe No changes noticed on the missfire data. Cylinders 4 missing somewhat at idle. Cylinder 5 missing a lot more. Intake manifold gaskets are about 20K miles. Plugs looked fine. O2 sensors (Bosch), injectors, plugs, wires are about 60k miles. Coil packs and cam position sensor are original. The truck was recently throwing P2135 codes and I replaced the throttle body and pedal position sensors as well as the throttle body eletrical connector/wiring. I believe that issue is fixed. Thinking the next test is a compression test. I'm not afraid of doing a cam position sensor replacement as I've had the intake off a few times and it isn't too bad of a hassle. Anyone run into anything like this? Any ideas? -
From the album: Diagnostics
Missfire data read from my Maxidas on my 2004 Tahoe 5.3L Flex -
I have an 05 4.8L Sierra with 293k miles. The last few weeks my truck has had a bit of a rough idle but runs fine other than that. Then my engine light flashed a few times which was P0308. I don't have a scanner that shows missfire count but i can say that in the last two weeks of driving back and forth to work 8 miles both ways, the CEL has only flashed once for P0308. I have swapped coils, wires, plugs, and injectors and it made no difference. I've sprayed carb cleaner around the intake with no change in idle/sound. After fighting with a compression gauge with damaged threads and dropping a plug on the concrete, ground strap down, i finally got to test compression today but the engine was cold and i only tested one side. Dry tests: Cyl 8: 140 Cyl 6: 195 Cyl 4: 190 Cyl 2: 215 Cylinder 8 wet test came out at 215. Fuel pressure with key on was 50, running at idle: 58. With all that said, this truck burns around half a quart of oil between oil changes (5k intervals) The compression test seems pretty conclusive that the rings are bad in cylinder 8. Should I give up and accept the fact that this engine is just about done or could there be something else causing the missfire? -
I recently bought a 96 Chevy, it has a miss fire at an idle and throws a p0300, and a p0303 codes. All the plugs, wires, cap, and rotor are new. It has 129000 miles and compression is good. I would think it would then be a fuel delivery problem at an idle? Any clues as to what it could be? Thanks
