P0302 only, CEL on '01 3.8L

[ogre73]

I have a 2001 with a severe misfire. It is causing the Check Engine Light to come on and sometimes (when real bad) to flash. I had the code read at Autozone and it reads ONLY P0302, Misfire Cylinder 2.
I have replaced the spark plugs with Motorcraft plugs, replaced the wires, changed the air filter, fuel filter, and run some Seafoam through the crankcase and fuel line.
Although it seems to run better at idle, when I shift the van into drive it starts misfiring badly.
I have been reading all sorts of things about the problem with the bolts, but because I am only getting this one code, and only the one cylinder seems affected, does anyone have any other ideas?
I will be looking to do something with this tomorrow, so if anyone has a suggestion I would love to hear it.
Thanks in advance.

[BCMedic]

Okay some random thoughts before you tear it all apart!

Check and compare the resistance of that plug wire to all the others. I have seen faulty wires out of the box.
Pull the plug again and check it for fouling.(double platinums?)
Remove, check and clean the plug to injector #2
Run a double dose of Seafoam or equivalent injector cleaner with a 1/4 fill of Chevron with the Techron additive.
Clean and check the IAC. When you put it in drive maybe the IAC isn't compensating for the drop in RPM.
Compression test the engine looking for varience in pressure. OBD2 systems will detect low compression/misfire caused by a bad or broken ring, worn cam lobe, bad lifter, burnt or carboned up valve ect.
Possibly check the coil.
Try these low cost things first and let us know before you think about tearing it down, replacing gaskets, injector ect.

[ogre73]

Thanks for the reply!
I hate the thought of jacking it up again, but I think I will get back under and pull that plug.
What do you mean by the plug to injector #2?
I am going to add two bottles of Techron to the tank tonight.
I bought a Haynes manual last night, so will check the IAC according to that. One thing about that, though; if it was something in the IAC or other components common to all cylinders, wouldn't the fault be different? It seems isolated to cylinder 2...
I have no idea how to compression test the engine. I will do some reading tonight.
I thought of the coil, but replacing that is a job that involves a lot of work, and if I'm going to do that, I might as well remove the plenum and clean the EGR ports. I'll post my results as soon as I get them.

[BCMedic]

My responses in bold.

Originally Posted by ogre73

Thanks for the reply!
I hate the thought of jacking it up again, but I think I will get back under and pull that plug.
What do you mean by the plug to injector #2?
Remove the electrical connector(plug) to injector #2 which is the back center one on the fuel rail, top of engine. Check it for corrosion, looseness, bent or pushed in pins ect. You may need to go as far as removing the injector and cleaning it later if the easy fixes don't help.
I am going to add two bottles of Techron to the tank tonight.
I bought a Haynes manual last night, so will check the IAC according to that. One thing about that, though; if it was something in the IAC or other components common to all cylinders, wouldn't the fault be different? It seems isolated to cylinder 2...
Sometimes the IAC if starting to stick, will cause a misfire without throwing a code. I replaced the IAC on my 98 F350 and it solved a rough idle I had, no codes ever though.In your case the IAC is low on the list of possibilities. But wouldn't hurt to check and clean it.
I have no idea how to compression test the engine. I will do some reading tonight.
A compression tester is only about 20 bucks or can be rented or borrowed free from Autozone ect. your manual will have instructions on disabling the ignition system and fuel pump first and how to do wet and dry tests and what they mean. You could also rent or borrow a vacuum tester as well. Both of these will tell you alot about the health of your engine.
I thought of the coil, but replacing that is a job that involves a lot of work,
The coil pack is quite easy to replace, but first check your new manual as it has a testing procedure for it. and if I'm going to do that, I might as well remove the plenum and clean the EGR ports. I'll post my results as soon as I get them.

[ogre73]

I just got in from testing the IAC. That appears to be fine. I checked the voltage, resistances, and took it off and cleaned it.
I also tested the voltages on the DPFE, and they are good. Not to say that I am eliminating that as a problem, but the voltages are good.
When I said that replacing the coil pack was a lot of work, I meant reaching it. Unless I take the plenum off, I can't reach it. Which also means I can't reach the injector plug on the rear.
I noticed when I gave the throttle a tug while running that there was a rush of air from behind (or maybe leaking from)the plenum. It is almost like someone is making a loud SHHHH! sound, but does it once and then stops unless I give it gas again. I saw this thread http://www.automotiveforums.com/vbul...&highlight=egr where the gentleman seemed to have the same sound.

[BCMedic]

Originally Posted by ogre73

I just got in from testing the IAC. That appears to be fine. I checked the voltage, resistances, and took it off and cleaned it.
I also tested the voltages on the DPFE, and they are good. Not to say that I am eliminating that as a problem, but the voltages are good.
When I said that replacing the coil pack was a lot of work, I meant reaching it. Unless I take the plenum off, I can't reach it. Which also means I can't reach the injector plug on the rear.
I noticed when I gave the throttle a tug while running that there was a rush of air from behind (or maybe leaking from)the plenum. It is almost like someone is making a loud SHHHH! sound, but does it once and then stops unless I give it gas again. I saw this thread http://www.automotiveforums.com/vbul...&highlight=egr where the gentleman seemed to have the same sound.

Have you tried carefully tightening the plenum bolts? You may need a new gasket if that doesn't help enough.
More info:
http://www.automotiveforums.com/vbul...ghlight=plenum

[12Ounce]

ogre
Don't let the plenum scare you, removing the wiper arms the first time may be the hardest part of this job.

I suspect you don't have your plug cables hooked up properly .... either loose, or misrouted. If you have a Haynes, you will see a diagram that will help you route the cables properly. Remember the plugs are numbered 1,2,3 from "vehicle right-to-vehicle left" on the rear of engine and 4,5,6 on front.

Its easy to get this confused.

[ogre73]

BC, the thread you gave is the same one I linked to.

12Ounce, I do have them correct. The wires are sized differently and as I was removing the plugs/wires I put the new ones on, one at a time.

Does anyone know if the shhh sound is normal with engine acceleration? If it is, I won't go chasing down that, but will continue to concentrate on the cylinder2 problem. I considered buying a set of Motorcraft wires, but they are 107.00! I can't justify that.

[BCMedic]

[quote=ogre73]BC, the thread you gave is the same one I linked to.

Sorry, I got there from a different search term.


Does anyone know if the shhh sound is normal with engine acceleration? If it is, I won't go chasing down that, but will continue to concentrate on the cylinder2 problem. I considered buying a set of Motorcraft wires, but they are 107.00! I can't justify that.

Have you tried a stethescope (or length of hose) when it does the SHH sound? It would be interesting, maybe important to pinpoint that sound.

[wiswind]

If you take the upper intake manifold off.....
Clean the EGR ports, Usually a missfire from clogged EGR ports shows up on Cylinder #1 and/or #4....as the ports seam to clog closest to the EGR valve and the mentioned cylinders are the farthest away from the EGR valve......and end up getting all the EGR gasses.....causing the missfire.

I chased a slight missfire for several months.....finally, it got bad enough to light the CEL.....was cylinder #1. In my case it was crud on the end of the fuel injector. It had not cleared up in several treatments of injector cleaner.....
The crud was inside the injector "cap" which is over the spray end........
You have to remove the injector from the lower intake manifold....then a shot of some carb. cleaner will rinse it right out.
You will want to clean ALL 6 injectors if you go to the trouble of getting to 1......as all of them will have some crud in there.
My problem showed up at about 137K miles......and is normal at that many miles.....it made a real big difference in performance when I did the cleaning.

I am not familiar with the swish noise that you are talking about. You have a different upper intake manifold on your 2001 than I do on my '96.

[ogre73]

I took the upper plenum off and cleaned the EGR ports. THey weren't really dirty. There was a fair amount of oil pooled in the lower plenum, though. Enough for there to be a pool nearly covering the head of one of the screws. I know it probably didn't make much difference, but I did tighten the 8 bolts a little. I didn't have the 12/ea for new bolts, and wasn't getting any of the codes that would indicate a failure like the one described by everyone for the TSB. I cleaned everything up and put it back together, and it still has problems. I bit the bullet and took it to the dealer yesterday. I will know today what they find. I figure that the $76 they charge for diagnostic is less than the money I would have spent trying the guessing game approach, which is what this has turned into. After the initial CEL came on and gave code P0302 at autozone, I changed the plugs, wires, fuel filter and air filter. I then disconnected the negative terminal and it cleared the CEL from the dash (I don't know about the computer). Since then, even though I have run the van at least 10 times, it hasn't come back on. I don't know what to make of that. I guess we'll see what they say.

[wiswind]

Some oil in there is normal....however, it sounds like you have a lot.
There is an improved front valve cover....which your '01 should have. The improved valve cover has an improved baffel over the PCV exit....You should not be able to see a hole in the baffel when you remove the PCV valve.....and shine a light down the hole.
I would recommend that you check to be sure that you have a Motorcraft PCV valve.....and that it "rattles"....as in not stuck open.
Some aftermarket PCV valves can let too much air pass through....pulling excessive oil with it.
Too much oil into the intake....will deteriate the isolators on the bolts in the intake......
Also, too much oil getting into the intake....will be drawn into the engine....and cause carbon buildup inside the cylinder....causing the engine to not perform as well.

[ogre73]

I'm still waiting on a verdict. I did hear from them, they said that it was a cylinder 2 misfire problem. That's what it was originally, but then after I changed plugs and wires, and cleared the light, I wasn't sure if it was still that. They swapped plugs, swapped wires, and did compression check, all good. They were running an ignition system check (whatever that means) when I last heard from them. Seems to me that the fact that it's isolated to cylinder 2 indicates (by virtue of elimination at this point) a problem with the coil pack or the fuel injector. But I guess we'll see what they say...

[ogre73]

Originally Posted by wiswind

Some oil in there is normal....however, it sounds like you have a lot.
There is an improved front valve cover....which your '01 should have. The improved valve cover has an improved baffel over the PCV exit....You should not be able to see a hole in the baffel when you remove the PCV valve.....and shine a light down the hole.
I would recommend that you check to be sure that you have a Motorcraft PCV valve.....and that it "rattles"....as in not stuck open.
Some aftermarket PCV valves can let too much air pass through....pulling excessive oil with it.
Too much oil into the intake....will deteriate the isolators on the bolts in the intake......
Also, too much oil getting into the intake....will be drawn into the engine....and cause carbon buildup inside the cylinder....causing the engine to not perform as well.

I do have a Motorcraft PCV valve, and it does rattle. As a matter of fact, I just bought a new different brand at autozone and had to return it because it has a metal "tit". The metal won't go into the hard plastic elbow, the way the Motorcraft one does, so I am glad I didn't toss the older one. Instead, when I cleaned the plenum I also took the carb cleaner to the hose and PCV valve assembly and cleaned the entire run from the valve cover to the intake port. Nice and clean and moves very nicely now.

I don't have the nice unpainted valve cover, I have the black one. But it doesn't appear to have the hole. I looked on a few different occasions, including with a shop light, and couldn't see one. Maybe that's just a matter of time.

[ogre73]

Well I'm pissed off. The dealer had the van for two days and charged me an hour and a half of labor to tell me that they don't know for sure how to fix the problem. They confirm that it is cylinder 2 misfire, and wanted to change the coil pack for an outrageous sum of money. Needless to say I told them forget it; if this was going to be a guessing game, I'll do the guessing and the work.
Man, they never even tested the coil. They actually told me that there was absolutely no way to test the coil. I guess their ford certified master mechanic has never heard of a digital multimeter or a coil tester? Man. I'm pissed!