I have a 97 Ford Ranger... V6, 3L, auto.

During my emissions test, I was told that I need a new coil pack to pass. I don't know much about the coil pack.

But for a couple of years now, my truck tends to be slow to switch gears and sometimes shifts hard. I asked if the coil pack would have anything to do with that, and the mechanic said yes.

I know the obvious choice of problem would be with the transmission. But I've had the transmission looked at before and it didn't appear to have anything wrong with it.

So could the coil pack REALLY be at fault for this problem?

Thanks.

 

It really sounds like your mechanic is taking you on a ride. FWIW, the coil pack will throw a code and make your check engine light come on when they go, I think it's PO351.

 

Thanks for the reply, Tiggie.

I don't know where you're located and what the regulations are, but I'm in Ontario. We have to get emissions tests. The actual diagnostics showed that I was in need of a Coil pack to pass the emissions test. However, there were parts needed before the coil pack, and the total parts cost was high enough that I was able to fix the preliminary parts and get a conditional pass instead.

However, my main concern was whether or not the coil pack would cause this problem of shifting. Are you saying the coil pack would have nothing to do with that?

I believe the explanation was that because the coil pack was working properly, the cylinders weren't all firing at once, and that would cause the delay in shifting.

Does that make sense? What are your thoughts on this problem?

Thanks for your reply, Tiggie.

 

All I can say is put it on a scanner and run all the codes. If the scanner will look at freeze frame info post it here

 

I'm not buying it either. I don't see how an emissions test can determine that a coilpack is bad. Determine a misfire, OK, but that doesn't automatically translate into a bad coilpack (and very rarely ever does).

In response to the particular question, it is possible that a misfiring engine (due to a bad coilpack) could cause bad shifting, but in reality it hardly ever works out nice and neat like that, at least not without trouble codes being set, and so I doubt that's what is going on in your case.

 

I haven't had my check engine light come on or any other sensors do anything out of the ordinary.

What do you guys, in your opinion, think the problem is?

 

my 1996 chevy corsica i had back in the day, was a 2.2 4 cyl.

my corsica lost significant power, decrease speeds up hill, made a spitting sound sometimes when i stepped on it, plus it didnt respond to me stepping on it,

i change fuel filter,pcv valve, air filter, spark plugs and wires, changed all fluids. changed a couple of more things to but i forgot what they were.

still the same problem.

i put in new coil packs, as soon as i did it, first test drive no problems at all. this was at 165k on it. it went back to driving great.

 

also this was in mass when i was there, they have one of the most strict emmisions test i the country.

and there was no way it would have even achieved enough rpm's to do the emmissions test.

if you dont have any of those symptoms like i had, i wouldnt start replacing everything under the sun, you mine as well have a reputable garage look at it, not an emmisions station/gas station.

 

By chance has the O/D light flashed any? Your tranny is controlled by the PCM (engine computer), and it uses about 20 inputs to decide how to shift. There is a connector under the drivers seat (someone else verify please)? I think that sometimes corrodes, you can check there.

 

I can't say for your specific problem, but I CAN say that's I've repaired MANY coil packs on Fords that never set a code.

I usually see it on V8 expeditions and F150's, but it's possible on any vehicle. The coil doesn't fail completely, but produces a weak spark causing a partial misfire, not a complete misfire. This usually has symptoms that develop during high load conditions, such as highway driving or hard acceleration, but the vehicle will run perfect well at idle and light acceleration. Usually no codes are set.

The Ford WDS tool has a neat cylinder balance test you can run while you drive... and watch a graph showing how much each cylinder was contributing, and if you see one lower than the other you know which coil pack to replace. Of course you'll only find this at a dealership.

Now your '97 3.0 ranger has one coil that fires all six cylinders, so if that is in fact the problem, it kind of takes the guesswork out of which coil to replace Good luck

 

TIGGIE... the O/D light doesn't flash either.

MAZDARANGER... thanks for your input. Sounds like maybe I should try replacing the coil pack.

 

Welcome to FTE goosefreek.

What were the failing numbers on your emissions test??? Was the computer scanned for trouble codes, if so list ALL the codes they found.

Which parts did you replace, to get the conditional pass on your emissions test????

Here in the States, most autoparts stores can bench test a coil pack for output. So maybe a store like Canadian Tire, or the like, where you are, could do this for you, if you really suspect the coilpacks output is weak under load.

As the guys have said, there are a number of things that could cause rough shifing, so you need to do some good smart troubleshooting, before throwing parts at the problem.

Would be helpful to know how many miles/km you have on this ride & how it's been maintained, like where you are on past & present, due scheduled maintenance items & what brands were used.

Also if the computer wasn't scanned during the emisions testing, have you since, had the computer scanned for trouble codes???? If so list ALL the codes found during this problem.

You can have trouble codes stored in the computer & still not have a Check Engine Light!!!!! So. if you've not had the computer scanned for codes, why not consider having it done, as any stored codes can sometimes offer up good clues for a successful troubleshoot.

Here in the States, most autoparts stores will do this at no cost, so call around where you are & see if a place like Canadian Tire, ect, will do a no cost scan & then post ALL the codes found.

Your emissions problem & sifting problem may, or may not, be related, so keep an open mind at this point.

Just some more ideas to ponder. Let us know what you find.

 

The '97 3.0L vulcan has EDIS and uses a coilpack containing three coils.

I'm still wondering how an emissions test can pinpoint a coilpack problem.

 

PAWPAW... the only thing I failed on during my emissions was my nox (NO ppm). I've replaced the EGR Valve and everything along the exhaust system (except the catalytic converter, but there didn't seem to be a problem with it according to the diagnostics test). I can't seem to find my paperwork to show what all I had replaced.

As for codes... I don't know if the computer was scanned... they did a test to figure out what was wrong, but I don't know what test they did.

My truck has a little over 200,000 kms (which is less than miles, fyi) and I always do my maintenance on time. I have actually never had any engine trouble or much trouble at all with the truck... just when it came to emissions... and as for the delay in firing or shifting... it's been doing that for a long time.

Beings it's been having that problem for upwards of 3 years... if it was the transmission, wouldn't it have went by now?

Thanks everyone for the suggestions and help.

 

it cant from what i understand.....if you have actual coil pack issues look at my post and see if are experiencing any problems like i had.

i imagine that those arnt the only symptoms of a coil pack issue,but you should be relating to what i went through.

it will drive like your suppossed to have a v8 but only feels like firing 2 cylinders.

spitting,no power, lose speed going on an uphill.