Is it ok to drive a truck with a bad coil / spark plug?

Gdetrailer wrote:

carringb wrote:
Fords will shut off the injector once it sets the code, so there should not be any adverse affects.

No, does not.

Have had a bad COP, never set any lights, no codes just a low speed miss. Idled perfect but give it a bit of throttle and the miss would start and get worse up to about 45 MPH then even out a bit up to 55.

Only way I found out was to take to the Ford dealer, pay the diagnostic fees and with their OBD2 computer it gave the percentage of power imbalance between cylinders.

On another truck the dealer failed to properly torq the plugs and had a miss and raw fuel smell in the exhaust.. No codes and no light..

I retorqed the plugs, no more raw fuel smell in the exhaust.. BUT, after a few thousand miles I started getting codes set for one of the OXY sensors..

The raw fuel dumped, poisoned the OXY sensors..

Read what he stated, and depending on year, it will shut off the injector.

Naio wrote:
Followup question:

There was another Ford van I looked at with a misfire. I took it to a mechanic to check it out, and he said rain water got in there. (I checked the Ford forum and saw this is a common problem with these vans, a design flaw, there are some fixes.)

Windshield water can drain onto one of the coils if you are parked downhill. Not a problem if the boots are in good condition, however some folks re-use them when they change the plugs, and that lets the water pool and short out the coil. But old cols can simply age out too. They seem to start going after 12-15 years regardless of mileage. I changed all mine preventively around 360,000 miles after I had two go out in a year.

jerem0621 wrote:

carringb wrote:
Fords will shut off the injector once it sets the code, so there should not be any adverse affects.

My 97 F150 with a 5.4 had a miss and it did destroy the cat. Not sure if that early model had the fuel injector shut off or not?

I had to cut a relief in the exhaust just to get to the repair shop...100% clogged cat is no fun.

Thanks!

Jeremiah

I think that safety feature was added in 2000 and newer Triton motors.

Second what Bryan said. I have an 06 4.6 Explorer with 225 k miles and dealt with more misfires that I care to remember. You do not wash the cylinder, the injectors do not get power when there is no spark. Drove hundreds of miles with a misfire when it happened on a family trip (no towing), and since changing the plugs on my 3 valve is not something you can do on a parking lot, I drove it home with OD off to keep rpm high and just keep going. Nothing happened to the engine.

I think you are looking at a c**p shoot, probably would be fine.

But shooting c**ps on something like that could ruin your day.

I drive Ford vans at work. I could always tell right away when a coil was bad. Bad coils do not always set a latched code. It happened so often the mechanics stopped arguing with me. This was on a 2001. Many of the Triton's at work burn oil too. It does not seem to be a big deal. Be sure to check the dipstick occasionally. One quart or so per 3k miles.

My current 2013 Ford van has not had a bad coil plug yet at 24k miles. New record for me.

Hmm... should i pay a mechanic to check out this van, or just forget it?

I have it scheduled at a shop tomorrow morning. But i don't want to waste the $100 they will charge me if it is clearly not going to be a good van for me.

(BTW, multiple mechanics have told me a compression check on a van would be $400-500, because they have to tear out so much stuff to get access. Apparently checking all the spark plugs is out, too, IIUC. Some are easy to get at and some are buried?)

On the Fords. the Triton motors have COP (coil) issues. a lot that have a misfire are due to a bad coil. rain can create a problem, but most coil failures are on the engines that haven't been maintained properly. the gap on the plug gets large and the col has to work harder to create a spark. that is when the coils start going bad. I have 91k miles on my V-10 and the plugs were done at 50k, will be done again at 100k. I have the OE COP`s and boots. I do however carry 2 spares with me, because they can fail. but the chances are slim on a well maintained engine!

And BTW, I forgot about this before when I posted. on a lot of the late 90`s and up engines (usually OBDII), when the PCM sees a hard misfire it can shutdown the fuel injector on that cylinder to protect the engine and cats!

Good luck on finding something.

don,t give up on this one,theres so meny IF,s . have the engine checked exhaust checked . and see what shows ,this could be a great unit. nobody on here knows for sure ,were all just speculating.

Followup question:

There was another Ford van I looked at with a misfire. I took it to a mechanic to check it out, and he said rain water got in there. (I checked the Ford forum and saw this is a common problem with these vans, a design flaw, there are some fixes.)

Mechanic fixed it an said the van is good to go, I could go ahead and buy it. He is a Ford truck specialist, but a stranger to me.

Was this mechanic BSing me?

I learned after the fact, from the dealer who has that van for sale, that he does some work for them. (I said, 'Oh, so he is YOUR guy, not my guy!' Dealer said, 'He's not our guy; we take our cars to all the mechanics around here.' I said, 'Oooo... they are ALL your guys :( '. This does seem a wise strategy if you are a dealer, but not so great for me.)