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2002 GT misfiring in cylinders #2 & #3 with a misfire in first 1000 revolutions

4K views 24 replies 5 participants last post by  Neuron 
#1 ·
Hey guys, first post here & looking for some suggestions. A few weeks ago the check engine light came on and it was misfiring in cylinders 2 and 3. I replaced both coils and all 8 spark plugs (didn't have money to do all 8 coil packs). I cleared the codes and within 20 miles they came back on with the same codes. I replaced the crankshaft position sensor and the camshaft sensor. The check engine light never went off but it didn't feel like it was misfiring, didn't really notice any loss of power either.

About a week ago I noticed that my engine was over heating at idle and I ended up being low on coolant, and I noticed an antifreeze smell coming from my exhaust and a minimal amount of white smoke. I know that head gasket replacements can be upwards of $1,500 so I went to autozone and got the BlueDevil head gasket sealer, followed the instructions and the leak stopped, no more smell and no more white smoke. I cleared the misfire codes thinking that the coolant may have caused a misfire in two adjacent cylinders although it's rare. The light stayed off for almost 200 miles before it came back on with the same codes as before and I can't find much online about adjacent cylinders misfiring so I'm wondering what you guys think.

Things I've done:
Coil packs
Spark Plugs
Unplugged affected cylinders and injectors while engine was running to see if it was the connectors, it isn't.
Injector cleaner with Premium fuel (93)
Crankshaft Sensor
Camshaft Sensor

Things I haven't tried yet that might be worth while:
removing the injectors and cleaning them
replacing the wire connectors anyway
After adding the Blue Devil sealer to the antifreeze, I have not (but probably should) remove/replace/clean the spark plugs from the two cylinders.

I'm a broke college student currently working for free (internship) so any suggestions or thoughts you guys have that don't involve taking it to a shop would be extremely appreciated.

I am not the first owner and the two owners before me did not keep the car in great shape but she's mine now and I want this car for life. She has 189,530 miles on her with regular oil changes.

Thanks for the help guys
 
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#2 ·
You likely still have a blown head gasket issue. Get a FelPro gasket kit for the top of the engine and pull it apart.

I'm not a fan of the liquid fixes. They normally cause more problems than they claim to repair.
 
#5 ·
A good set of wrenches, ratchets, sockets, and a torque wrench.

It honestly sounds more terrifying than it is to pull the heads.

Go slow, take pics, mark and label every part and bolt, and follow the Chilton's or Haynes manual. It will likely take you a full day with a friend while taking your time.

A few of the guys on here can likely pull a set of heads and have the car back together in a few hours.
 
#7 ·
I do have the Haynes repair manual, I haven't looked through it yet to see if head gaskets are in there. I think over the next few days when I have free time I'm going to eliminate the other possibilities like the injectors, just because when the light first came on and I was misfiring, I wasn't losing coolant and you couldn't see or smell it anywhere; so I think consistently running on 6 cylinders and pushing the car too hard may have caused the blown head gasket, and not necessarily the other way around; however I'm no expert so you may well be correct in that it is still the head gasket.

As soon as I turn the key the car jumps to life and then falls to about 500 RPMs before staying steady at 750, with or without the air being on, its usually after the engine is cool. I've noticed that when I accelerate you can hear a slight noise, I'm not sure how to describe it other than it may sound like it's not getting enough gas? kind of a shakey/rattling noise. My car makes another noise, although I don't think they're related, but if I'm not at a high RPM when I push in the clutch it will make a quick "errrt" chirp noise, like someone is washing windows.

Shout out to anyone near South Jersey / Philadelphia area who would volunteer to help me out and let me learn a thing or two. Beer and food is on me.
 
#8 ·
I have a buddy that works in the HR department at the local Autolenders Service Center and I've become acquainted with the mechanics over there and whenever I drop my car off for an oil change or work that I can't do myself I'm usually asking them questions about what could possibly be the problem, and recently they said that the ERG valve could be stuck open / closed (I forget which he said), but how likely is that to happen, and if it did would it affect two adjacent cylinders? or would it affect all of them
 
#13 ·
Took my car in this morning to get an oil change (had it changed 1,000 miles ago before the head gasket went) because I thought it looked a little milky brown and wanted to be safe rather than sorry. They said it wasn't too bad, and I'm not losing any coolant at all. I had them check for leaks all over and it was ok at the time. Got her home, disconnected the fuel in the trunk and released the pressure because I was going to clean my injectors but then I realized I didn't have enough time before I had to leave so I decided to just clean the 2 spark plugs off. #3 was really dirty and #2 wasn't so bad. put everything back, turned on the fuel and she roared right up and didn't drop RPMs on start up and she feels great now. I've turned it on 5 times since (11:45m) and have driven about 30 miles without any issues and the CEL is still off. I know it takes 2 consecutive driving cycles with a detected issue for it to come on, I'm not sure how long/far a drive cycle is but I've heard that if it doesn't come in in 50-100 miles it's probably not going to.

Previous trip w/o CEL was 46 miles, and before that was 200. praying that with fresh oil, clean+new spark plugs, new coil packs and no leaks that she'll be firing on all cylinders now
 
#15 ·
yeah at least until I have the time & the money to order the felpro kit and actually take my time doing the repair correctly. also going to have to buy a torque wrench at some point, replaced my intake manifold without one and one of the bolts didn't catch correctly and ended up allowing the manifold to shake enough to loosen the other bolts and cause a coolant leak. Good times
 
#17 ·
A useful trick you can do is to swap the fuel injectors from those cylinders to other known good cylinders and see if your misfire codes follow them to those cylinders. You can do the same with the coil packs and spark plugs. If you have a blown head gasket a compression check should be able to show something is up.
 
#19 ·
Yeah I've swapped the coil packs and it stayed in the same cylinders, I went out and cleaned (not swapped) my spark plugs when I realized I didn't have enough time to clean the injectors. So far so good, the check engine light hasn't come on yet and has been driven over 200 miles
 
#21 ·
Revvv, got a question. figured I would just ask you here instead of making a new thread, I purchased Fel-Pro valve cover gaskets because mine are leaking and the guys at the shop wanted about $400 to do them, and I got the gaskets for $28. Do I, or should I, replace the bolts? I know you need to for head gasket bolts, but I couldn't find anything about replacing the valve cover ones.
 
#24 · (Edited)
It is always a good practice to replace the head bolts. I have reused head bolts in the past with no problems, but it is not recommended due to the bolt stretching under the correct torque. However, you're not pulling the heads, only the valve covers.

Reuse the valve cover bolts, etc.

Follow the torque patterns and do everything exactly as the book says.

Ziploc bags and a Sharpie marker will be a life saver when removing and replacing bolts.

Also, take photos of everything, and do not be afraid to ask questions.
 
#25 ·
Make sure the seating surfaces are really clean and do not over-tighten the valve cover bolts. If you are going to do much work on this I highly recommend a Ford Factory Shop Manual(Chilton etc OK to supplement the Factory one), it will pay for itself many times over and you can sell it when you sell the car.
 
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