Need Help! Misfires/Check Engine!
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Joined: Dec 2001
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From: Tulsa OK
Need Help! Misfires/Check Engine!
So I was driving this morning and started to get misfires followed by a check engine light. Since I was near the dealer I brought it over and hoped he would be open. They were, and they got it in pretty quickly. They *say* they checked the coils. Anyway, after an hour he said he still didn't know what the problem was and told me to come back Wed. I was a little hesitant to drive away with a blinking Check Engine but I did.
Brought the car home and ran an autotap on it. First, I have massive misfires on Cyl 6 even at idle.
As for the Check Engine.. I have a 0300 "Misfires Detected" in my long term log, and a 0306 in my long term and my pending. However, there is no description for the 0306. What is this code? When she cools down I might pull the plug myself but I thought I'd run this by you guys as well.
Thanks and happy holidays,
Adam G
Brought the car home and ran an autotap on it. First, I have massive misfires on Cyl 6 even at idle.
As for the Check Engine.. I have a 0300 "Misfires Detected" in my long term log, and a 0306 in my long term and my pending. However, there is no description for the 0306. What is this code? When she cools down I might pull the plug myself but I thought I'd run this by you guys as well.
Thanks and happy holidays,
Adam G
Instructor
Joined: Sep 2000
Posts: 247
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From: Central Florida
Re: Need Help! Misfires/Check Engine! (GTXgp)
I recently had the same problem. The dealer diagnosed a misfire in cylinder #7. He said a computer glitch caused a misfire that resulted in a fouled plug. They reprogramed something in the computer and replaced the plug and it runs great now.
Burning Brakes
Joined: Dec 2000
Posts: 849
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From: Lafayette LA
Re: Need Help! Misfires/Check Engine! (Vettepartz)
Yep. It's 30X - X is a number 1-8 that is the misfiring cylinder.
Hope it's something obvious. It's a complex detection scheme and finding the cause can get weird.
Hope it's something obvious. It's a complex detection scheme and finding the cause can get weird.
Instructor
Joined: Aug 1999
Posts: 247
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From: Green Bay WI
Re: Need Help! Misfires/Check Engine! (GTXgp)
Could also be a wire, or a coil. One thing you could try, is swap your #6 wire with another and see if the mis-fire moves to the new cylinder. If it doesn't, then try swapping the coil packs. This should help you narrow it down. Be sure to clear the codes in the computer before each swap.
Good luck.
Good luck.
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Melting Slicks
Joined: Aug 2000
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From: Newland US
Re: Need Help! Misfires/Check Engine! (RadarBlue)
Could also be a wire, or a coil. One thing you could try, is swap your #6 wire with another and see if the mis-fire moves to the new cylinder. If it doesn't, then try swapping the coil packs. This should help you narrow it down. Be sure to clear the codes in the computer before each swap.
Good luck.
Good luck.
You offer a sound diagnostic approach. I might add that if all of the above indicates the ignition is OK on the misfiring cylinder, try cycling (unplug and replug) the injector connection on that cylinder.
Good luck running it down, Adam.
Mark
Racer
Joined: Jun 2000
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From: Phoenix az
Re: Need Help! Misfires/Check Engine! (GTXgp)
Had a similar experience about a month ago. My 2001 would misfire so bad tha the whole car would shake, but it did not throw any codes. The dealer could see the missfires on their diagnostic tool at high and low RPM. The dealer ended up replacing a plug and wire, they installed a new PCM , swapped several plug wires and finally replaced another plug. So far so good.
Bob
Bob
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From: Tulsa OK
Re: Need Help! Misfires/Check Engine! (azarby)
You aren't the first one who has said the dealer did something with the PCM, and I find that rather odd. I'm wondering if there is some kind of inherent problem with some of our PCMs? I've decided at this point I'll just bring it to the dealer (take advantage of my warranty while I still have it :smash: ) but I'll suggest a few things when I go over thanks to this thread :D
Adam
Adam
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From: Tulsa OK
Re: Need Help! Misfires/Check Engine! (Buckmaster)
No aftermarket stuff on the car right now. I just got the car a week ago :)
I brought it in this morning. They said they checked all the usual misfire stuff. However, they have said something weird. They mentioned something about the compression on Cyl 6 and about it being lower than normal? They say they ran some type of engine flush and it brought the compression up closer to normal, but they want to do it again and let the flush sit overnight... all this sounds kinda strange to me, but I guess you have to trust that these guys know what they are doing :rolleyes:
At least crap like this happens now instead of when I have mods on the car...
Adam G
I brought it in this morning. They said they checked all the usual misfire stuff. However, they have said something weird. They mentioned something about the compression on Cyl 6 and about it being lower than normal? They say they ran some type of engine flush and it brought the compression up closer to normal, but they want to do it again and let the flush sit overnight... all this sounds kinda strange to me, but I guess you have to trust that these guys know what they are doing :rolleyes:
At least crap like this happens now instead of when I have mods on the car...
Adam G
Le Mans Master
Joined: Oct 1999
Posts: 8,205
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From: Tucson AZ
Re: Need Help! Misfires/Check Engine! (GTXgp)
The "flush" procedure is probably to "de-carbon" your engine. You may have had so much gunk in there that the valves were not working properly, or the plug(s) were fouled. Good luck! :yesnod: :smash:
Melting Slicks
Joined: Dec 2001
Posts: 2,410
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From: Boulder CO.
Re: Need Help! Misfires/Check Engine! (carpe dm)
Ask the dealer to do a leak down test. They probably did a compression test already.
Did you check the actual condition of the # 6 plug? That will tell the story.
Since you just bought the car, it's hard to determine how hard the car might have been driven. The leak down test is to see if the rings are worn out.
Did you check the actual condition of the # 6 plug? That will tell the story.
Since you just bought the car, it's hard to determine how hard the car might have been driven. The leak down test is to see if the rings are worn out.
Melting Slicks
Joined: Aug 2000
Posts: 2,248
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From: Newland US
Re: Need Help! Misfires/Check Engine! (GTXgp)
No aftermarket stuff on the car right now. I just got the car a week ago :)
I brought it in this morning. They said they checked all the usual misfire stuff. However, they have said something weird. They mentioned something about the compression on Cyl 6 and about it being lower than normal? They say they ran some type of engine flush and it brought the compression up closer to normal, but they want to do it again and let the flush sit overnight... all this sounds kinda strange to me, but I guess you have to trust that these guys know what they are doing :rolleyes:
At least crap like this happens now instead of when I have mods on the car...
Adam G
I brought it in this morning. They said they checked all the usual misfire stuff. However, they have said something weird. They mentioned something about the compression on Cyl 6 and about it being lower than normal? They say they ran some type of engine flush and it brought the compression up closer to normal, but they want to do it again and let the flush sit overnight... all this sounds kinda strange to me, but I guess you have to trust that these guys know what they are doing :rolleyes:
At least crap like this happens now instead of when I have mods on the car...
Adam G
If the misfires are because of low compression, then I'm doubtful that any kind of a flush will cure it.....although it's possible maybe there are some rings stuck on #6 piston. I hope that it isn't because a slightly bent valve is not sealing properly. They should be able to get some good indication from a careful compression test or better yet do a leak down check on it. That certainly should pinpoint the valves or the rings and in the case of the leak down test, if it is a valve they should be able to determine whether it's intake or exhaust. Hopefully it's not something that serious where the head has to come off.
Let us know what they discover.
Good luck.
Mark
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From: Tulsa OK
Re: Need Help! Misfires/Check Engine! (MDT)
Yeah, they say the flush didn't fix the compression completely. That's why they are letting it sit overnight supposedly.
First thing tomorrow I'll ask about the Leak Down Test.
I'll keep you all updated...
Adam
First thing tomorrow I'll ask about the Leak Down Test.
I'll keep you all updated...
Adam
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From: Tulsa OK
Update
Well, I went over and had a long talk with the service rep at the dealer this morning. He says they haven't done a leak-down test yet. At this point they've given up on electrical and carbon build-up. He said they are going to check the rods/springs tomorrow and they are hoping that's the problem. On the plus side, I got a thorough carbon-engine flush for free :jester
I'll let you guys know what they find.
Adam
I'll let you guys know what they find.
Adam
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Joined: Dec 2001
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From: Tulsa OK
Update
Well, I've had it with the stupid dealer. :mad They've had the car for 5 days and haven't touched the engine problem nor my reverse light problem. So I took the car back and picked up some rods at the parts dept before they closed and I'm about to pull the valve cover off. I'll let you all know what I find...
Adam
Adam
