Dude, thank you so much for this video. You have inadvertently given me a clue as to what was going on with my project civic. I was running out of ideas as to why I had such violent and erratic misfiring. The engine had been extremely overheated, likely multiple times by the previous owner. I had fixed the root cause being a bad water pump, did the head gasket, and had the head machined. I had also redone the entire top end of the engine, still using the original coil packs. I never thought that the coil pack stems had stress cracked and were likely arcing to the spark plug wells, not the plugs. I went out and got four new NGK coil packs and sure as hell, the car is now punchy and running well with no codes or misfiring anymore. Thank you for the insight!
Same here. Replaced coil packs and spark plugs (which were only a year old, but car had overheated) after replacing all the sensors and the starter, water pump, belts. Started up immediately after this. Thank you!!🎉
My 08 Civic is at 325,000 miles and I just did everything you did. New oem serpentine belt and new oem belt tensioner too. Now I just need the ngk coil packs. I didn't think of this. 😂 I guess I can do the maintenance anyway with so many miles. I will get to half a million miles on this sucker tho!!!
If you drop them down the spark plug well you need to regap them. When i was an amatuer i did that and figured it wouldn't be a big deal. The car idled fine but instead of getting 30mpg i got on average 24mpg. I opened the gap back up from .039in to .044 and the car had a lot more lower end power and fuel economy restored. It's a common mistake... its not worth spending 10 bucks a plug to replace them. Just regap em. You aren't going to damage the center electrode with a gapping tool. The tool is made exclusively to bend the ground electrode without touching the center electrode!
So, the situation you've described fits mine well. 2017 Honda Civic overheated. A few days later, I got misfires in cylinders 2 and 3. I replaced all four spark plugs and ignition coils. The same rough idle and codes came up after a few days. The car always starts fine the first time I drive it in a day, but later on it starts to idle rough on subsequent ignitions. If I put it in neutral and rev it to 2k, it smooths out most of the time, though. Next, I ran a fuel system cleaner through, and the car was doing okay for a bit but would periodically idle roughly upon ignition (again, always after it had been driven that day and to varying degrees of roughness). I'm thinking I need to check the fuel injectors now to see if they need cleaning or replacement, but I'm not really sure if I should look for something else first. I haven't checked compression, I realize after watching this. Anyone have any tips?
Doubt fuel injectors are the problem. make sure the new spark plugs are not defective, I have seen cheap plugs fail after a few days, get some NGK from a reputable source. to check for a blown head gasket, you need a combustion leak detector kit.
Not sure if you found the problem (or still have the car...) but it could be a bad EGR. You can try disconnecting the EGR valve to see if the engine runs smoother.
changed sparkplugs, changed coils 2 and 3 (that were misfiring), serviced the car and the problem still persists... misfire detected in cylinder 2 and 3... we even swapped the injectors and still misfiring... any insight? I really don't wanna fix a blown head gasket
I cha my plugs but on my 4th cylinder I striped are cross threaded the plug and now I have alot of it packed down so deep in the cylinder is that a big job to fix, on a Honda element
I definitely would have done a leak down on it... Cylinders 2 & 3 looked like they were immediately losing compression when he stopped cranking it over.
Need help folks, 06 EX changed sp and coil and the p303 came back again with engine misfire, turning off the engine restarting fixes shudder, what is the solution.
want car I would do a compression test to make sure you don’t have a bad head gasket or burnt valve. Also inspect the wiring and socket that connect to the coil to ensure you are getting a good connection.
I started to have p0300, p0302, p0303, p0304 codes when engine is heated. So far ive replaced all spark plugs, all ignition coils, EGR-valve and yesterday camshaft sensor. Spark plugs were changed like 2 month ago and check them like week ago and they were really dirty and some of them must have been heated up alot cause of colour of them even they were only 2 month old. Cleaned them with wire brush which didnt help. Timing belt was changed 4 month ago along with water pump aswell. Havent done compression test yet but i try to do that soon.Not sure if this helping but exhaust pipe is making coughing sound after engine is heated. Im really running out of ideas what it can be. Car is Civic 2003 1.6 VTEC if anyone have ideas what to look for next.
Hi really appreciate this, it's brilliant. Needed your expert opinion; engine light flashing and vsa light on turned on today (civic 2011). Code demonstrated misfiring cylinder 1. changed coil pack and spark plugs around to see if the code would change but cylinder 1 still misfiring. Compression test is normal. What would the next step be? Is it likely injector or electrics from your experience and is there any easy way to know?
@@YourCarGuyDR You are very kind. I got this checked it was normal. Valve was normal. So I changed the first and fourth injector and all lights turned off, misfiring stopped and the car was smoother than before!! But 2 days later, now there's misfiring in the 3rd cyinder!!! Took me forever to open, I knew I should have changed them all. But from your experience could it be something else triggering them? Like a bad fuel filter for example? or anything else thats not on my radar Thanks a lot, you've helped tremendously in my mechanical journey
@@Oo786oO it could be a bad fuel filter or if you got some contaminated fuel. I would always recommend if one fails to change them all. But that can be tough with the price of injectors.
If you disconnect the battery for about 30 minutes it should reset the code. Vacuum leaks can be difficult at times to find. I usually listen and try to hear them which can also be difficult. You can use carburetor cleaner and spray near suspected areas with the motor running . If the motor stumbles or revs up then you have found your leak. However you have to be very careful as carburetor cleaner is very flammable and a stray spark or too much heat and you will have a fire to deal with.
@@YourCarGuyDR my lower radiator hose broke causing it too over heat,pulled over and checked had all those codes, even my oil dip stick got toasted is that a bad sighn
@@fernandocoronado4428 that can be a bad sign. Severe overheating can lead to a blown head gasket and possibly a warped or cracked head. My recommendation would be to replace the hose and fill the cooling system. Then run the vehicle to see how it behaves. If everything seems good change the oil and you should be in good shape. If. Or you are likely looking at a major repair.
@@YourCarGuyDR I replaced the hose with new coolant, the drive belt turns but doesnt start, My friend told me thats a good that sign it turned , a seized engine wont turn over.tommaro ill do what you did in the video.wish me luck.
My honda had same codes i checked changed the coil packs the car ran great. But when i parked it came oyt later to drive it the car wont start any suggestions
I have a random misfire on all cylinders I haven't done a compression test yet and I haven't overheated so I'm at a loss for guess until I do a further test. I hope to god it's not a head gasket
@@YourCarGuyDR I just finished that. Compression was excellent at 230 lbs across all four cylinders. Also 4 new Denso plugs and I still have the problem. The old plugs all 4 of them were dry black sooty..
@@YourCarGuyDR Random misfire on every cylinder. PO300, PO 301, 2 ,3,4. I'm concerned I may have a worn timing chain. I may try a fuel filter next. The car shakes/jerks upon low idle taking off but it fine beyond 3000 rpm
@@stephenjackson4392 I would try a set of coils before a timing chain. They are very easy to change. If that doesn’t do it I would inspect the cam and crank position sensors.
Gamer Cat when you say swapped I am guessing that you put new ones on? If that is the case you need to do a compression test. If the compression is good look at the wiring connectors and test the wiring. Could also be a bad ECM but that is not common on a Honda.
@@YourCarGuyDR yes i swapped out new plugs and wires and brand type is denso spark plugs and i did a compression test already readings were 145 to 150 its a 97 honda civic hx and i gapped the plugs a bit pre gapped in 0.40 but i gapped them to 1.1 but later got all cylinder misfire. And then put them back to 0.40 and its at p0302 and p0304 code again. And changed new coil too and i made a decision to replace injectors.
Gamer Cat okay make sure to replace your distributor cap and rotor if you haven’t already. I have seen ones that looked fine but would have a spark arc to another cylinder inside the cap.
I have changed the plugs and coils but still my car is misfiring. The car started doing that after the tappets were adjusted and throttle body cleaning. Could it be because there is debris stick in the engine?
Fahed Sayed it is doubtful that it is from debris unless while adjusting the tappers somehow a piece of metal got on the cam sensor. I would also verify that the ground wire for the top of the engine is hooked up.
@@YourCarGuyDR I connected the scan tool it had absolutely no errors but especially when the car is cold the exhaust sounds like it's coughing or sputtering you can say
@@YourCarGuyDR yes it started the next day when I started the car Then I took it to another Honda dealer and they re adjusted the tappers but the engine still shakes at Idle however the noise is not there anymore
Fahed Sayed if the rappers were incorrectly adjusted it is possible that a valve got bent. This would cause a backfire either out the exhaust or intake or for that cylinder to simple not fire at all. Did the second dealer mention anything about it being way out of adjustment?
Cheeze Face no they are not the same. In most newer cars there is a coil for each spark plug that will mount just above the spark plug. In some cases it will be connected to the plug via a spark plug wire. In other cases like on the engine in this video the coil has a “boot” that connects it to the plug and is generally part of the coil assembly.
xart23x you are welcome to believe whatever you like. My 30 years of experience, manufacturer training, master tech status in 3 separate OEM’s, and as a dealership trainer I will respectfully disagree.
So, you're saying I'm right? I ask because researching, it said go according to firing order but, this guy says otherwise as do others. Trying to help others as well as myself cuz I got p0303 code recently and I smell gas from tailpipe. Discussion is healthy. Still not sure who is right.
Dude, thank you so much for this video. You have inadvertently given me a clue as to what was going on with my project civic. I was running out of ideas as to why I had such violent and erratic misfiring. The engine had been extremely overheated, likely multiple times by the previous owner. I had fixed the root cause being a bad water pump, did the head gasket, and had the head machined. I had also redone the entire top end of the engine, still using the original coil packs. I never thought that the coil pack stems had stress cracked and were likely arcing to the spark plug wells, not the plugs. I went out and got four new NGK coil packs and sure as hell, the car is now punchy and running well with no codes or misfiring anymore. Thank you for the insight!
Same here. Replaced coil packs and spark plugs (which were only a year old, but car had overheated) after replacing all the sensors and the starter, water pump, belts.
Started up immediately after this. Thank you!!🎉
I m not a mechanic but you must be a master teacher very well explained I did the job at ones thanks for helping people with your knowledge 🙌🏼
My 08 Civic is at 325,000 miles and I just did everything you did. New oem serpentine belt and new oem belt tensioner too. Now I just need the ngk coil packs. I didn't think of this. 😂 I guess I can do the maintenance anyway with so many miles. I will get to half a million miles on this sucker tho!!!
Great video man we are all very greatful for the video ended being a bad coil for me , driving great now!
Excellent video, very instructive for beginner trying to troubleshoot this code.
i guess I'm quite randomly asking but do anyone know of a good place to watch newly released series online?
Good job, excellent video well presented!
Good presentation, very helpful.
thank you for the diagnostic tips.
Very helpful, thanks so much!
Thank you. Excellent video
Great explanation and thorough
thank you man appreciate the knowledge
Love the blunt wrapper in the floorboard. Lol
I have a same Issue hopefully i will fit it up 😊
Nice video brother, thank you
Great video sir!!!
Honda makes the best engines.
Great video man thank you for making it
Funny,i watch this then...i changed mine,,it was #3 coil
Cracked,thanks saved 60.oo labor
great video thank you very much
Great…. It’s really helpful…. THANKS
Amazing video
If you drop them down the spark plug well you need to regap them. When i was an amatuer i did that and figured it wouldn't be a big deal. The car idled fine but instead of getting 30mpg i got on average 24mpg. I opened the gap back up from .039in to .044 and the car had a lot more lower end power and fuel economy restored.
It's a common mistake... its not worth spending 10 bucks a plug to replace them. Just regap em. You aren't going to damage the center electrode with a gapping tool. The tool is made exclusively to bend the ground electrode without touching the center electrode!
Great video.
You can explain yourself well... Lot of people can't
Hondas always get NGKs...its to avoid problems down the road.. Thanks for the video.
👏👏
Thanks for the info
in order to do compression test, you have to remove all the coil plugs , and spark plugs or can you leave them in there and do 1 by 1 cylinder?
So, the situation you've described fits mine well. 2017 Honda Civic overheated. A few days later, I got misfires in cylinders 2 and 3. I replaced all four spark plugs and ignition coils. The same rough idle and codes came up after a few days. The car always starts fine the first time I drive it in a day, but later on it starts to idle rough on subsequent ignitions. If I put it in neutral and rev it to 2k, it smooths out most of the time, though.
Next, I ran a fuel system cleaner through, and the car was doing okay for a bit but would periodically idle roughly upon ignition (again, always after it had been driven that day and to varying degrees of roughness).
I'm thinking I need to check the fuel injectors now to see if they need cleaning or replacement, but I'm not really sure if I should look for something else first. I haven't checked compression, I realize after watching this.
Anyone have any tips?
Doubt fuel injectors are the problem. make sure the new spark plugs are not defective, I have seen cheap plugs fail after a few days, get some NGK from a reputable source. to check for a blown head gasket, you need a combustion leak detector kit.
@@directautofix Thank you for the reply. I appreciate the insight, and I'll bump a compression check up to the top of my list.
Not sure if you found the problem (or still have the car...) but it could be a bad EGR. You can try disconnecting the EGR valve to see if the engine runs smoother.
Tenx bro.....
Left right after you said Bosch would be fine 😬😬
I love you bro
Thank you
Nice one
nice
changed sparkplugs, changed coils 2 and 3 (that were misfiring), serviced the car and the problem still persists... misfire detected in cylinder 2 and 3... we even swapped the injectors and still misfiring... any insight? I really don't wanna fix a blown head gasket
Check your compression, if it is low then you will know if you have to dig into the engine.
I cha my plugs but on my 4th cylinder I striped are cross threaded the plug and now I have alot of it packed down so deep in the cylinder is that a big job to fix, on a Honda element
Antwayan Owens there are thread repair kits that can be done without removing the cylinder head. Otherwise the head will need to be pulled, big job.
Sometime compression test will not show a blown head gasket . A leak down test will.
I definitely would have done a leak down on it... Cylinders 2 & 3 looked like they were immediately losing compression when he stopped cranking it over.
Need help folks, 06 EX changed sp and coil and the p303 came back again with engine misfire, turning off the engine restarting fixes shudder, what is the solution.
want car I would do a compression test to make sure you don’t have a bad head gasket or burnt valve. Also inspect the wiring and socket that connect to the coil to ensure you are getting a good connection.
I started to have p0300, p0302, p0303, p0304 codes when engine is heated.
So far ive replaced all spark plugs, all ignition coils, EGR-valve and yesterday camshaft sensor. Spark plugs were changed like 2 month ago and check them like week ago and they were really dirty and some of them must have been heated up alot cause of colour of them even they were only 2 month old. Cleaned them with wire brush which didnt help. Timing belt was changed 4 month ago along with water pump aswell. Havent done compression test yet but i try to do that soon.Not sure if this helping but exhaust pipe is making coughing sound after engine is heated.
Im really running out of ideas what it can be. Car is Civic 2003 1.6 VTEC if anyone have ideas what to look for next.
Run the compression test, it sounds like you may have a bad valve in the cylinder head.
Do u guys know if need to change the spark plugs? Or the spark plugs coils?
El Zacatecano509 most of the time you will need a cool with a misfire. It is a good idea to change the plugs as well.
Hi really appreciate this, it's brilliant. Needed your expert opinion; engine light flashing and vsa light on turned on today (civic 2011). Code demonstrated misfiring cylinder 1. changed coil pack and spark plugs around to see if the code would change but cylinder 1 still misfiring. Compression test is normal. What would the next step be? Is it likely injector or electrics from your experience and is there any easy way to know?
Oftentimes is can be the wiring connector at the coil. An injector can cause it as well.
@@YourCarGuyDR If it is the wiring connector at the coil, can it still cause the physical sound of misfiring?
@@Oo786oO yes it can.
@@YourCarGuyDR You are very kind. I got this checked it was normal. Valve was normal. So I changed the first and fourth injector and all lights turned off, misfiring stopped and the car was smoother than before!!
But 2 days later, now there's misfiring in the 3rd cyinder!!! Took me forever to open, I knew I should have changed them all.
But from your experience could it be something else triggering them? Like a bad fuel filter for example? or anything else thats not on my radar
Thanks a lot, you've helped tremendously in my mechanical journey
@@Oo786oO it could be a bad fuel filter or if you got some contaminated fuel. I would always recommend if one fails to change them all. But that can be tough with the price of injectors.
Is there another way to reset the code without a tool scanner ? I wish you did a video also on how to check vacuum leaks.
If you disconnect the battery for about 30 minutes it should reset the code. Vacuum leaks can be difficult at times to find. I usually listen and try to hear them which can also be difficult. You can use carburetor cleaner and spray near suspected areas with the motor running . If the motor stumbles or revs up then you have found your leak. However you have to be very careful as carburetor cleaner is very flammable and a stray spark or too much heat and you will have a fire to deal with.
@@YourCarGuyDR my lower radiator hose broke causing it too over heat,pulled over and checked had all those codes, even my oil dip stick got toasted is that a bad sighn
@@fernandocoronado4428 that can be a bad sign. Severe overheating can lead to a blown head gasket and possibly a warped or cracked head. My recommendation would be to replace the hose and fill the cooling system. Then run the vehicle to see how it behaves. If everything seems good change the oil and you should be in good shape. If. Or you are likely looking at a major repair.
@@YourCarGuyDR I replaced the hose with new coolant, the drive belt turns but doesnt start, My friend told me thats a good that sign it turned , a seized engine wont turn over.tommaro ill do what you did in the video.wish me luck.
My honda had same codes i checked changed the coil packs the car ran great. But when i parked it came oyt later to drive it the car wont start any suggestions
Jason Cartwright check your connections and check your fluids. When it doesn’t start does it crank over?
Yes it cranks
Jason Cartwright if it cranks over smoothly I would pull the spark plugs and check to see if they are wet and smell like fuel.
I have a random misfire on all cylinders I haven't done a compression test yet and I haven't overheated so I'm at a loss for guess until I do a further test. I hope to god it's not a head gasket
If you can do a compression test it is helpful. You may just need plugs
@@YourCarGuyDR I just finished that. Compression was excellent at 230 lbs across all four cylinders. Also 4 new Denso plugs and I still have the problem. The old plugs all 4 of them were dry black sooty..
@@stephenjackson4392 do you just get the random misfire code or do you also get a code for an individual cylinder?
@@YourCarGuyDR Random misfire on every cylinder. PO300, PO 301, 2 ,3,4.
I'm concerned I may have a worn timing chain. I may try a fuel filter next. The car shakes/jerks upon low idle taking off but it fine beyond 3000 rpm
@@stephenjackson4392 I would try a set of coils before a timing chain. They are very easy to change. If that doesn’t do it I would inspect the cam and crank position sensors.
Hi. What compression tester is that?
James Kuchek this is just a generic one I picked up at the local parts store.
My Honda civic 2003 coupe ex is misfiring on all 4 cylinders and p0300 code, i don't know what could be, any help guys?
Oscar & CR Fans it is possible you have an issue with your cam position sensor.
@@YourCarGuyDR other thing is that doesnt accelerate as before. and thanks for the reply man appreciate it👍😁
I have the same error codes, had spark plugs replaced, check engine light back on. Could it be the ignition coils?
Christopher Rodriguez usually it is the coil and not the plug that is bad.
I have cylinder 2 and 4 misfire i swapped coil and spark plugs and wires still the problem.
Gamer Cat when you say swapped I am guessing that you put new ones on? If that is the case you need to do a compression test. If the compression is good look at the wiring connectors and test the wiring. Could also be a bad ECM but that is not common on a Honda.
@@YourCarGuyDR yes i swapped out new plugs and wires and brand type is denso spark plugs and i did a compression test already readings were 145 to 150 its a 97 honda civic hx and i gapped the plugs a bit pre gapped in 0.40 but i gapped them to 1.1 but later got all cylinder misfire. And then put them back to 0.40 and its at p0302 and p0304 code again. And changed new coil too and i made a decision to replace injectors.
Gamer Cat okay make sure to replace your distributor cap and rotor if you haven’t already. I have seen ones that looked fine but would have a spark arc to another cylinder inside the cap.
I have changed the plugs and coils but still my car is misfiring. The car started doing that after the tappets were adjusted and throttle body cleaning. Could it be because there is debris stick in the engine?
Fahed Sayed it is doubtful that it is from debris unless while adjusting the tappers somehow a piece of metal got on the cam sensor. I would also verify that the ground wire for the top of the engine is hooked up.
@@YourCarGuyDR I connected the scan tool it had absolutely no errors but especially when the car is cold the exhaust sounds like it's coughing or sputtering you can say
Fahed Sayed did this start right after the tappers were adjusted?
@@YourCarGuyDR yes it started the next day when I started the car Then I took it to another Honda dealer and they re adjusted the tappers but the engine still shakes at
Idle however the noise is not there anymore
Fahed Sayed if the rappers were incorrectly adjusted it is possible that a valve got bent. This would cause a backfire either out the exhaust or intake or for that cylinder to simple not fire at all. Did the second dealer mention anything about it being way out of adjustment?
Is coil pack the same as a spark plug wire?
Cheeze Face no they are not the same. In most newer cars there is a coil for each spark plug that will mount just above the spark plug. In some cases it will be connected to the plug via a spark plug wire. In other cases like on the engine in this video the coil has a “boot” that connects it to the plug and is generally part of the coil assembly.
@@YourCarGuyDR you are the best, you're the master, thanks.
Doesn't p0302 indicate the second cylinder in the firing order, not necessarily cylinder 2?
xart23x no the codes are not by firing order but are done by cylinder number
Respectfully, I think I'm right. The second cylinder in the firing order is the culprit. Look it up.
xart23x you are welcome to believe whatever you like. My 30 years of experience, manufacturer training, master tech status in 3 separate OEM’s, and as a dealership trainer I will respectfully disagree.
@@xart23x why did you ask a question if you know the answer?
So, you're saying I'm right? I ask because researching, it said go according to firing order but, this guy says otherwise as do others. Trying to help others as well as myself cuz I got p0303 code recently and I smell gas from tailpipe. Discussion is healthy. Still not sure who is right.
1:36 sec you know that car smells like weed
yewww...Bosch....