04 Ford Taurus: Check Engine Light on After Torque Converter was Replaced

This car has been giving me quite a bit of trouble lately. 04 Ford Taurus SES, about 97,000 miles on it. Just last weekend, it broke down on the highway. Found out the torque converter failed and needed to be replaced. I was suspecting that something was wrong with the transmission for a while now, because it would stutter sometimes when accelerating, and sometimes start shaking in the front when I turned it on. (It still stutters after having the torque converter replaced.)

Well now, a day after shelling out quite a bit of money to the dealer for this torque converter, the check engine light is on. I went to Autozone to check the codes, and they found P0300, P0305 (cylinder misfire) and P0316 (“crank sensor condition”) Does anyone know if this is a serious problem?!? Is it possible the transmission is failing?? I found a bunch of complaints online about the transmission failing on the 04 Taurus. I’m trying to avoid more expensive repairs, but I don’t want the car to break down on me again…

Also, a couple months ago, the check engine light went on a few times, but always went off within a day or two. Never did get it checked out because it didn’t stay on long enough.

Any ideas/advice would be greatly appreciated!!!

The crank sensor is a frequent problem reported here, not necessarily on Fords, but on an assortment of cars. If the crank sensor fails, misfiring could easily occur. This may have nothing to do w/the xmission, usually doesn’t, so cross your fingers and hope it is just that you need a new crank sensor. It’s also possible in fixing the xmission last time, the wiring connectors to the crank sensor were damaged or not put back together correctly, and the connector has worked loose. In which case fixing that may be all you need. Think positive!

It could be that this problem was misdiagnosed from the start. I’m really not buying the converter being the cause of being stranded instantly on the highway.

A faulty crank sensor can be erratic in operation and leave you stranded though along with setting a random misfire code (300) and the specific cylinder misfire code (305) could be due to a faulty spark plug, plug wire, or even coil.

JMHO, but I tend to think the original stuttering and shaking was due to an ignition miss that has now gotten worse.
Codes can exist in the computer’s memory so the fact that the CEL is not on doesn’t mean that much.

Granted, I don’t know all of the facts behind this converter diagnosis but offhand it stinks a bit.

Thank you for this info!! If it helps any, what happened when my car broke down was this: While I was going about 65, with no prior warning, the car suddenly started slowing down. I kept pushing the gas, but it would not accelerate, it was like it was just revving the engine. It was making a very loud screeching sound, smelled like something was burning, and the check transmission light came on. I managed to coast it down an exit ramp before it completely stopped. At that point, it would not drive in any gear - kinda like it was in neutral. I had to have it towed to a dealership.

That could point to a massive converter problem and a bit of an unusual situation. There would be concern over any debris in the the transmission and hopefully things will work out well there.

That being said, the original stuttering and shaking could very well point to a crank sensor problem along with a plug/wire fault.
Does this car by chance still have the original spark plugs in it? FOMOCO makes recommendations about 100k miles spark plugs but that’s not often the best thing to do either.
A failing plug can kill a plug wire and in time can even kill a an ignition coil.

“Crank sensor condition”? Who told you that? P0300 indicates a cylinder misfire, random in that the computer can not figure out which cylinder is misfiring. P0305 indicates cylinder #5 misfire. P0316 indicates a misfire within the first 1000 revolutions of starting the engine. It’s not likely at all that the crank sensor is at fault here, more likely an ignition problem like a spark plug or ignition coil or a plug wire. The stuttering you mention could easily be a cylinder misfiring, probably #5.

Hmmm… Autozone told me P0316 was a crank sensor condition. Do you know how much it would normally cost to fix a spark plug, ignition coil, or plug wire?

If they indeed replaced the torque converter, they will have had to separate the transmission from the engine. In doing that, they likely pulled a wire loose or disturbed it so that it is intermittent now.
It is a bit unusual to have a torque converter fail, but I’m not second guessing their diagnostics.

If I were you, I’d bring it back and say “I know you had to separate the engine from transmission and suspect you messed something up…” and see what they say.
Don’t let them charge you for it.

I’d guess anywhere from $50 to $300. Next step is an actual and thorough diagnosis from a reputable repair facility.

I would go along with ok4450, the engine was probably missing in the first place, not the touque comverter.

I took it to the dealer to have it looked at… They said it was a failed ignition coil. They wanted to replace all the spark plugs and the ignition coil for $620… Sounded too expensive so I declined repairs. I might take it elsewhere to see if I can get the same thing done for less.

@Em985 you don’t think you could replace the coil and plugs yourself?
Unless you have to remove the plenum to replace the plugs on the firewall side, it shouldn’t be a big deal. Ratchet, sockets, extensions and a spark plug socket . . .

No, I don’t… I’m not mechanically inclined. I don’t want to risk the chance of screwing it up.

@Em985 well . . . in that case, if you’re reasonably confident of their diagnosis, you could ask another shop (not a dealer, of course) for a quote to do the job. Make sure you know which coil is bad, in case there’s more than one.
You do have the written estimate, right?

I got the ignition coil and one spark plug replaced at a smaller shop for much cheaper! I’ll deal with the other spark plugs later. But for now, it is driving smoothly… knock on wood

@Em985 Congratulations on getting your problem resolved for a reasonable price!


As you can see, you should start getting quotes to replace the remaining 5 spark plugs, perhaps in conjunction with the next service/tune-up.
If you liked this last shop, perhaps they should be the ones to do it.

I will only add that the remaining plugs should be replaced as many coil failures are due to an aged, misfiring plug.
Just my 2 cents, but the shop should have recommended replacement of the other five if they did not.

Thanks all for the advice, it seems like the repairs are neverending on this car. I got the rest of the spark plugs replaced in May and thought everything was taken of. Then last week, my car started stuttering again – mostly when it’s idle. But it was stuttering pretty badly so I took it to the dealer. I thought maybe it was an ignition coil again because the check engine codes indicated an engine misfire.

When the dealer called back, first thing they asked was what repairs I had done recently. I told them about replacing the torque converter, spark plugs, etc. Apparently the new spark plugs that were put into the car were the generic kind that does not work well with Ford. Also, a coil on the cylinder needs to be replaced, so they want to replace all the spark plugs again, replace the coil, and do a stress test on the remaining 5 coils for about $1000. I was not expecting such an expensive quote! And I JUST paid ~$600 to replace the spark plugs previously.

So, my question is: does this sound like a reasonable price for these repairs? And are they really necessary? If I don’t replace the spark plugs, will they cause lots of other problems?

Well, a problematic spark plug could indeed damage a coil. The coil produces a spark, and the voltage it sparks at depends on the spark plug and its gap. If the gap is too wide, or something else is wrong, it will spark at a higher voltage than it is supposed to, and could damage the coil, and other stuff perhaps.

hmmm … Generic spark plugs don’t work well on Fords? I guess I’ve never heard of that before. But it is critical that the spark plug be one that is specifically recommended in the owners manual. Did the shop put in a spark plug brand/part number not in the owner’s manual? If so, yes, they should all be replaced with correct spark plugs. And yes, the coils are now suspect, and should either be all replaced, or at least stress tested, if they actually have the ability to do that.

I’ll add that if this were my car, I’d bite the bullet and replace all the spark plugs and all the coils and be done w/it. I’d probably replace all the spark plug wires too, with OEM replacements. I’d shop the job around to several inde shops who’ve been recommended to me by friends, co-workers, fellow church goers, etc. And I’d tell the shop who it was that recommended me. Best of luck.