cylinder 3 misfire after getting coil replaced a week ago.

[drake3988]

My CEL came on and the code for a cylinder 3 misfire came up. I got this replaced the 23rd of December and the CEL is back on saying the same thing a week later? any suggestions or similar problems? i also had a cylinder 4 misfire 3 months ago and had the coil replaced as well. any help would be greatly appreciated thanks

 

[BFEATHER2008]

OK i had the same thing happen on my 98 4Runner. first off is what i did was i replaced spark plugs and the wires. then it came back on and i a cylinder 4 misfire. well i asked my father about it (mechanic for Toyota for 30years) and he said we need to switch a coil so take the coil pack from the cylinder thats misfiring and switch it with one thats not. if the cylinder misfire changes cylinders then its the coil. if not its most likely the fuel injector. ok i work for O'Brien Toyota as a parts salesman. ive seen this alot and you could have gotten a bad coil pack new from the dealer or where ever you got it. ok first switch then like i said if it changes take the coil back to where you got it from and tell them its bad.
Good Luck getting it fixed I know its a pain but you got to what you need to.

 

[drake3988]

Thanks a lot, i'm going to the Toyota dealership and they are going to check it out for me hopefully its just a bad coil and not my fuel injectors!

 

[BFEATHER2008]

Yea that would be great fuel injectors are about 190 here in indpls,in. Good luck on it.

 

[theizzardking]

My CEL came on and the code for a cylinder 3 misfire came up. I got this replaced the 23rd of December and the CEL is back on saying the same thing a week later? any suggestions or similar problems? i also had a cylinder 4 misfire 3 months ago and had the coil replaced as well. any help would be greatly appreciated thanks

most likely a plug and wire, same thing happened to me, replaced the coil then misfire came back 3 days later, it would seem that bad plugs and wires can cause the coil pack to go bad and cause a misfire, so if you only replace the coil pack with out replacing the plug and wires the problem will reoccur and since you now have a new coil pack in there you don;t have to worry about that, just go for the plug and wire....what i'm trying to say is a bad plug and wire can make an old coil pack go bad but the new one should be fine with the bad plug and wire, just swap out the plug and wire and reset the ecu and the problem should be gone.

to be honest you should have just swapped the plug and wire yourself and saved the cash, it's around $110 an hour for a tech to poke around inside your car.....

 

[sn0wrunner]

yep I agree with what others have posted. I had the same problem, and it was the plugs and wires. Easy fix

 

[TN22Corps]

I'd agree too, having also had a cylinder 4 misfire. Switched the coil packs around, CEL came back still as cylinder 4. So, new plugs and wires did the trick.

Good luck.

 

[drake3988]

Not looking good, Toyota can't figure it out but said they were leaning toward head gasket which caught me off guard. Hope its a cheaper problem

 

[brian2sun]

Start with plugs. No wires on #3 (just the coil directly above it) so the coil would be next. Since you've already replaced the coil, I highly doubt you got a defective OEM one. So If it's not the plug, move onto testing the injector. Then pull the injector and visually inpect for clogs. THEN, if that stuff doesn't help look into it maybe being a head gasket. Until then keep an eye on your coolant level. If your HG is leaking, then you will loose coolant. Personally, I think the dealership you brought it to did a shabby job of diagnosing so I hope you didn't pay them to stare at it and guess because that sounds to me exactly like what they did - since they don't seem to even be following the steps own service manual.

Keep in mind that when you are checkng your coolant level, the level fluctuates when the engine is hot/cold. Always check the level in your clear overflow container on level ground and after you've been driving for a while. You could also get a compression test and/or a leak-down test if the HG actaully becomes a real suspect. HGs aren't common whatsoever on 3.4s so I give that about a 1-3% chance of being your problem.

The next logical thing that it could be if you've ruled out all of the above is a valve issue (maybe burnt or just out of adjustment). That's about all the "normal" things that would cause a miss.

 

[fenrisx]

I'll be keeping an eye on this ! I had a cylinder misfire (and really jerky driving from it). So I did plugs & wires. Problem solved for about 1 month.. now I've got P0141 which could be from cylinder misfire, but I didn't feel any misfire this time.

 

[theizzardking]

Not looking good, Toyota can't figure it out but said they were leaning toward head gasket which caught me off guard. Hope its a cheaper problem

for what you've paid them already you could have confirmed for a fact that it's not the plugs and wires by replacing them....it sounds as if to me the dealership is being lazy. like as if they are just standing around scratching thier heads until it trhrows a code, and of course they'll want to jump to the most expensive thing, that's how they make their money, it's not on parts as much as it is labour.

listen to brian, swap the plug out check the injector then have the valves checked then start looking at the head gasket....

logic dictates when searching for an unknown like this start cheap and easy and work your way down into the guts of the motor, not jump to a heart plug in the 2nd go......

unless the tech ran some of that spiffy uv oil through the motor and confirmed a head gasket leak, i'd call bs on them.....

ask for the uv oil test before they do anything it's cheap and take like 10 mintues

like this, maybe even order it yourself
Robinair 16268 Multi-Purpose Dye Oil/Fuel UV Dye - 6 pk.

 

[drake3988]

Thanks for all the help on this. I was there at toyota for about 2 hours and they drove it and had two guys on it so they say and it ran fine for them. he said everything was checking out good, checked the injector and it passed and also the pressure of cylinder 3 and it was perfect. i brought up a clogged injector and they scratched their heads some more and said yeah well that could be it too but still they think head gasket, but i dont have any symptoms of a head gasket except driving is a little jerkey when cold around 50 mph. Im about to just dive into the engine myself and try and figure this out. Thanks a a lot again for advice i hope to get this problem taken care of real soon!

 

[brian2sun]

Their HG diagnosis sound like horse**** to me. There are so many things that can cause a miss, I'm just wondering what clues they have that would lead them to that conclusion. If the radiator/overflow are empty, ok maybe a HG. If there's white smoke and/or water pouring out the tailpipe, ok maybe a HG. They need to provide you with eveidence if you're paying them. Otherwise it's like me on the internet saying... hmmmm... well... I think it's a headgasket.

 

[drake3988]

Yeah i feel the same way, he said he found sludge type material in the radiator and my overflow has never really held coolant, not sure why but it has always been low but my car never ran hot and i havent gotten white smoke or water out of the exaust. he just said headgasket because of the radiator but i havent seen what he was talking about and that was his only clue. im thinking about maybe doing the engine cleaning like you did and hope that helps if not it probably could use it anyway, i will keep the updates coming.

 

[brian2sun]

Yeah i feel the same way, he said he found sludge type material in the radiator and my overflow has never really held coolant, not sure why but it has always been low but my car never ran hot and i havent gotten white smoke or water out of the exaust. he just said headgasket because of the radiator but i havent seen what he was talking about and that was his only clue. im thinking about maybe doing the engine cleaning like you did and hope that helps if not it probably could use it anyway, i will keep the updates coming.

Well, it sounds like I probably didn't give the guy enough credit. With that info, it could be a HG. You should do a pressure test on the cooling system to see if/where it's leaking and a leak-down test on all the cylinders.

 

[drake3988]

ok well found the problem today. i finally got time to get under the hood and took my runner apart and found a cracked spark plug under coil for cylinder 3. cleaned maf sensor and k and n air filter and put new ngk wires on, never ran better!

 

[brian2sun]

That's good it's running nice now. I think you should still figure out why your overflow doesn't hold coolant though.

 

[drake3988]

That's good it's running nice now. I think you should still figure out why your overflow doesn't hold coolant though.

Yeah the best its ever ran, its holding it now but im going to keep an eye on it and its anything i think its a small hose leak somewhere ,gotta keep checking

 

[theizzardking]

Yeah the best its ever ran, its holding it now but im going to keep an eye on it and its anything i think its a small hose leak somewhere ,gotta keep checking

woop! woop! :trophy:

far far better case then an head gasket!!!!

a small hose leak is an easy fix to, if it's suspect just replace it, cheap part and quick fix!

 

[2runnersnyynyg]

Sounds like u should go to the dealer and ask why they didn't check while they put a new coil pack in? Misfire? He didn't think to pull the plug while he was there then came up w/hg diag? Not cool.sounds like someone was trying to make hours on you ? Take the plug and your receipt to the shop.