# Pontiac Vibe Misfire #2 Cylinder



## MichaelZ (May 21, 2013)

I have a 2003 Pontiac Vibe. Has been a great car, AWD, and in great shape. But about a month and a half ago, right after an oil change, I had a blinking check engine light (CEL) when I go up a hill and put a load on the engine. Had it checked - misfire on #2 cylinder. So I replaced the #2 coil. Same CEL. Replaced the #2 fuel injector. Same CEL. Also the plugs, all of them, to no avail. What I did seemed to help the car run a bit better, but did not get rid of the blinking CEL. Also replaced valve cover gasket as oil was getting in the plugs. I talked to the local shop and the guy there said I probably have a bad valve and he would have to run a compression test. A valve job is $1500+ !!! So I am getting a compression tester - cost $30 and it is easy to do myself. Am getting a good education here, so I am not so upset at what I spent so far. But do not want to chuck out $1500 or more on a 14 year old car with 199K miles. And the car runs fairly well now - just not quite as it should. Could the oil change have had an effect? Is there any additive that could get this valve working again, if it is a valve?

My thoughts now are to keep this as a work car, as is. But am wondering if this bad valve, if not taken care of, will cause other issues. If so how soon?


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## jwal10 (Jun 5, 2010)

May be lifters or cam. When was the timing belt changed? Loose? There is a problem, it WILL get worse....James


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## alleyyooper (Apr 22, 2005)

If it were the timing belt then the whole engine would be in a funk. If the mech. said probably valve he is probably right and the oil change didn't hurt the engine maybe allow ed the problem to manifest it's self.
After the compression test pull the valve cover off and make sure you don't have a rocker arm broken first.

Isn't all that hard to do a it your self valve job. Buy a service manual.

 Al


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## farmrbrown (Jun 25, 2012)

Ditto on Alley's post.
The oil change didn't cause it, just coincidence.
Your first fixes are what I would have done. Replace coil, plug, etc.
Had a similar problem with my Tacoma, same symptoms, and found the problem by accident when I went to change coil a second time.
I was ticked that I missed it, but I can pass it on to you.
*Plug wire.*
DOH!
The connection at the spark plug had a small break and it came apart in my hand.
Wires are cheap, try that next.


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## MichaelZ (May 21, 2013)

Thanks for the replies! If the compression test does not show anything I will look at the wire going to the #2 coil.


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## unioncreek (Jun 18, 2002)

Have you checked if there is any spark at the sparkplug. Could be the coil itself or how old are the plug wires?

Bob


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## jwal10 (Jun 5, 2010)

I only mentioned the timing belt as those engines have known top end oiling problems and cam wear. Removing the head for a valve job, a new timing drive system and checking the cam is good maintenance at those miles. Price doesn't seem so high when so many things can be serviced....James


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## MichaelZ (May 21, 2013)

unioncreek said:


> Have you checked if there is any spark at the sparkplug. Could be the coil itself or how old are the plug wires?
> Bob


The spark has been checked and it is OK. But then again, there is no noticeable issue until there is a load on the engine. And actually right now, other than the blinking CEL, I would not notice a thing with respect to drive-ability. 

In this engine, I believe there is a timing chain, not a belt. Or it is not an interference engine. I checked this out right away when I got the car. The timing belt monster has bit me in the past!


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## farmrbrown (Jun 25, 2012)

MichaelZ said:


> The spark has been checked and it is OK. But then again, there is no noticeable issue until there is a load on the engine. And actually right now, other than the blinking CEL, I would not notice a thing with respect to drive-ability.
> 
> In this engine, I believe there is a timing chain, not a belt. Or it is not an interference engine. I checked this out right away when I got the car. The timing belt monster has bit me in the past!


That was the same with mine. Sometimes it would run fine under a load, I guess because the wire connection was intermittent.
To be sure you can always swap coil packs (if there are multiple, mine has 3) and/or wires and see if the code moves to another cylinder.
Like I said, I was stumped for a few months and because the wire set was fairly new, I never suspected it.
You can also check the wires going to the coil. On an earlier repair, I found that it my engine was a favorite spot for rodents to get warm.......


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## Bellyman (Jul 6, 2013)

MichaelZ said:


> The spark has been checked and it is OK. But then again, there is no noticeable issue until there is a load on the engine. And actually right now, other than the blinking CEL, I would not notice a thing with respect to drive-ability.
> 
> In this engine, *I believe there is a timing chain, not a belt*. Or it is not an interference engine. I checked this out right away when I got the car. The timing belt monster has bit me in the past!


FWIW, timing chains don't always last forever. They can get a little sloppy over time and or break, even though they're not supposed to. I've heard some of them even require pulling the engine to get to 'em. UUGH!!! I kinda doubt it's your problem, but it was just something that came to mind.

FWIW II, I had an old Ford 302, maybe an early '80's model, can't remember, that had a nylon gear on the timing chain that ended up causing me grief. Can't imagine the brainiac that figured that was a good idea, but... (I doubt that's your issue either, but just recalling.)

Best of luck! I'll be interested to hear what it finally turns out to be if/when you figure it out.


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## alleyyooper (Apr 22, 2005)

I would also like to point out that a compression test may not show you a thing. If the valves are not opening at all due to a broken rocker arm you can have compression but still have that miss.

I really think I would either buy or check the library for a service manual for the car, Also keep in mind the vibe was built by Toyota and I think their model was called the matrix.










*Have you pulled the injector for that cylinder and checked for a spray and pattern?
I found this about that.*

" I have a 2004 Toyota Matrix, 2 WD, 4 cylinder. I've had the car since it was new, and starting in March of 2008 the check engine light has come on several times for a misfire on cylinder #2 (code P0302). First the intake gasket was replaced, then the ignition coil and spark plug, then the injector (twice), then all 4 plugs, then the ignition coil again, and now they are saying the injector is bad again. Always on cylinder #2. All of this at the dealer where I got the car.



I'm not sure how they've determined the coils have been bad, but they've moved the injector to other cylinders and the misfire has moved with the injector. Yet it always initially goes bad on #2.



One bit of frustration: while the notes aren't clear, the service guys have said that when they replaced injectors, they wouldn't go into #2. I.e., they would swap the injectors between #2 and #4, and when they found that the misfire moved to #4, they put the new injector in #4, rather than swapping back and putting the new one in #2. So it is unclear how old the injector currently in #2 is.



Initially, the car was under warranty, so I didn't have to pay anything, but as it stands now they want me to pay for a new injector since it is out of warranty. It seems to me like there's some issue that was happening while still under warranty that was causing this, but they said they can't think of anything. It seems odd that _any_ injectors would fail, _more_ odd that 3 would fail, and even _more_ odd that all 3 failures would occur on cylinder #2."

 Al


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## Texaspredatorhu (Sep 15, 2015)

Pop the valve cover and roll the engine over and make sure everything is moving properly. Not sure how they are sensing the misfires anymore via knock sensor or based on load or what. Does the light stay on all the time or just under load? I have seen a Diesel engine with a bent rod(hydrolocked) pass every cutout test and run better and better as it got hot and when you stall the hydraulics it chuffed and chuffed and fell flat on its back side. Another option is to get a bore scope and take a gander in the hole just to check it out. It's pretty easy on a gas engine. Roll it over with the scope in it to and you will be able to see the other side of the valves.


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## MichaelZ (May 21, 2013)

Well did a dry compression test with results:
#1 = 220
#2 = 210
#3 = 210
#4 = 210
So I am not seeing any sign of compression loss in #2. Did not bother with the wet test. So I am guessing electrical. I might unbundle the coil wires (after I label them) and inspect them. Seems like every time I jostle those coil wires around there is a change. 

I already checked resistance at the injectors - they were all equal. 

Is there a test I could do on the wires with my multimeter? Put one probe on each connector terminal and one on ground? Measure resistance?


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## farmrbrown (Jun 25, 2012)

MichaelZ said:


> Well did a dry compression test with results:
> #1 = 220
> #2 = 210
> #3 = 210
> ...



There are some ways to check on this link.
http://opensiuc.lib.siu.edu/cgi/viewcontent.cgi?article=1025&context=auto_pres


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## alleyyooper (Apr 22, 2005)

Have you checked the injector? it doesn't really have to be an electrical problem. Just swap the injector for # 2 with the one in # 4. Be care full with the old O rings.

 Al


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## nosqrls (Jun 9, 2012)

A set of injectors is 45$ set of coils 40$ if replacing 1 I would do them all. and that is with a 5 year warranty. It could be a bad spark plug right out of the box. or broken wire in engine harness.


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## MichaelZ (May 21, 2013)

OK here is the update: Somehow I got the idea from someone at an autoparts store that putting dielectric grease on terminals would help. It actually made it worse! So I cleaned that stuff off but car still ran bad. 

I got 3 more matching coils and 4 new iridium spark plugs. Found that it did nothing! MPG down to 20MPG or less! So I waved the white flag and took it into a real shop and gave them carte blanche orders to fix it, whatever is needed. 

Here is what he found:
1. The number one cylinder was dead, not the number two! And I had 3 different code scanners show me #2. But this guy had a scanner that checked individual cylinders. Lesson 1 - find a shop with an individual cylinder code scanner. Do not trust the parts store!
2. The coil and signal to the coil was good. So he checked the injector. #1 was dead. Now previous to this I think the injector worked somewhat unless under load but now it was dead. He said the #1 plug showed NO firing - and I just put that plug in last weekend. Also, he found the #2 injector I put in had an extra O-ring. Apparently from the old injector, although I thought I had gotten the old O-ring out! perhaps a previous repair? But he fixed that. Lesson 2 - don't leave the old O-ring in.
3. He replaced the #1 injector and the car runs fine! YAAAY!

BIG Lesson: A misfire can be tricky. Don't trust a guy that sells parts or a guy with a $200 scanner or even your friend with a floor jack that does discount repairs. Replace the plugs (or wires if you have them) but after that, take it to a good shop with proper equipment. Otherwise you can end up throwing a lot of money at the car with no results and you might even mess things up.


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## alleyyooper (Apr 22, 2005)

And I said it might be a injector problem some time back. Yes I did say # 2, per your saying the code was for # 2.

Any way glad you got it back running again those vibes are nice cars as is the Matrix from toy land.

 Al


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## Bellyman (Jul 6, 2013)

Thanks for the update! It's good to finally hear what the solution was.


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## MichaelZ (May 21, 2013)

Actually I had replaced the #2 injector and also checked the resistance of all injectors and checked them for function at idle. It was the #1 injector all along, but up until recently when it finally quit all together, it functioned fine except under heavy load. 

The shop gave me a nice new $180 injector ($50 at rock auto) but also did some great diagnostic work that the others could not do, so I was ok with pricey part. So for something like this paying the extra on parts ends up being cheaper in the long run.


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## Bellyman (Jul 6, 2013)

I understand about the $200 code readers not being up to every task. They have their place, and often they really can be very helpful. But sometimes, they just can't do what needs to be done. The guys who have professional shops, dealerships and others capable of that level of work, spend quite a few thousands of dollars on those machines and continue spending as updates become available. It takes quite a few $80 diagnostic charges to cover a $5k+ machine.

Sounds like the charges were substantial but not unreasonable. It's good that they were competent enough to get right to the heart of it without throwing the whole parts catalog at it... I've heard it can happen, even at some dealerships.

Again, glad it's running good again.


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## MichaelZ (May 21, 2013)

Actually, I misread the bill. The $180 was for labor. The injector was about $120, not quite as bad. The guy put in a lot of time and even drove it home one night just to make sure it was really fixed. But yeah, they have the expensive equipment - sometimes it is needed. I was almost desperate enough to take it to a dealership (gasp!) It was a humbling experience for me - sometimes that is not always a bad thing. It runs better than ever now - I feel like I just bought a new car!

When I had that replacement injector, the solution was in my grasp! If only I had replaced #1 instead! (And not left the extra o-ring in the engine). But hind-sight is always 20-20


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## Declan (Jan 18, 2015)

I have had similar problems on a Buick and it turned out to be the control module under the coil packs. The garage couldn't pick it up just relying on codes because it kept throwing random misfire codes. He reached out to other garages trying to figure it out. He definitely lost money on me just in the time he spent on the thing. It would run fine for a mile or two and I would be right back at the garage the next morning with a "Nope. Wasn't that."


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## fordy (Sep 13, 2003)

MichaelZ said:


> I have a 2003 Pontiac Vibe. Has been a great car, AWD, and in great shape. But about a month and a half ago, right after an oil change, I had a blinking check engine light (CEL) when I go up a hill and put a load on the engine. Had it checked - misfire on #2 cylinder. So I replaced the #2 coil. Same CEL. Replaced the #2 fuel injector. Same CEL. Also the plugs, all of them, to no avail. What I did seemed to help the car run a bit better, but did not get rid of the blinking CEL. Also replaced valve cover gasket as oil was getting in the plugs. I talked to the local shop and the guy there said I probably have a bad valve and he would have to run a compression test. A valve job is $1500+ !!! So I am getting a compression tester - cost $30 and it is easy to do myself. Am getting a good education here, so I am not so upset at what I spent so far. But do not want to chuck out $1500 or more on a 14 year old car with 199K miles. And the car runs fairly well now - just not quite as it should. Could the oil change have had an effect? Is there any additive that could get this valve working again, if it is a valve?
> 
> My thoughts now are to keep this as a work car, as is. But am wondering if this bad valve, if not taken care of, will cause other issues. If so how soon?


.............If an oxygen sensor has gone bad it will be sending inaccurate readings to the main computer and engine won't run right ! , fordy


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## MichaelZ (May 21, 2013)

Back up to 30mpg  This is the top end of mpg for this AWD.
The steady CEL came back on. The previous owner said overfilling the gas would trigger this. And this guy had his own GM dealership to try and diagnose this. I suspect O2 sensors - I think I will replace these over the summer as I think they should be replaced anyway being I am over 200k. At any rate, the car runs fantastic now.


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## MichaelZ (May 21, 2013)

Latest update: check engine light went off again. Most recent mpg at about 32mpg! Mostly highway, but still higher than spec brand new!


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## jerrystead (Oct 19, 2011)

The compression test verified that there were no internal issues with your engine, which meant that it had to be an external component (plug, coil, wire, injector, bad connection), yes it can be tricky at times, but just eliminate one potential issue at a time.


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