Shaking

I have a '01 Explorer XLT with a V8 and 102,000 miles. My check engine light is on, and when I'm idling or traveling 45-50 mph my car shakes. I've changed spark plugs, wires, and even an oxygen sensor. Any ideas? The mechanic claims it is a misfire code. Maybe I need new fuel injectors? Thanks for any help.

I have a '01 Explorer XLT with a V8 and 102,000 miles. My check engine light is on, and when I'm idling or traveling 45-50 mph my car shakes. I've changed spark plugs, wires, and even an oxygen sensor. Any ideas? The mechanic claims it is a misfire code. Maybe I need new fuel injectors? Thanks for any help.

Take it to autozone and have them read the code for you (they will do it for free) and post the specific code on here.

I had my explorer tested at Autozone. Results below. Any help is appreciated.

PO307 - Misfire on #7
PO174 - Running lean

I had my explorer tested at Autozone. Results below. Any help is appreciated.

PO307 - Misfire on #7
PO174 - Running lean

I believe you should have ignition coil packs, I would recommend trying to replace those. That should take care of the misfiring. Check www.rockauto.com they are usually cheaper than autozone. As far as your running lean it is going to be something that your going to have to pinpoint. I would start by getting a fuel pressure gauge and check your fuel pressure to eliminate the fuel pump as being the problem. If your not getting adequate pressure then try replacing your fuel filter first and then replace your pump. I don't know of how to check to see if your fuel injectors are working right I only know how to check to see if they are shooting fuel. They make what are called mechanics stethoscopes they sell them at autozone. But you just listen to each injector and you should hear a strong steady click from each injector. If you don't then that injector needs to be replaced. Give that a try and let me know.

How diffucult is it to change the ignition coil pack. Is this something for a real mechanic? And about how much??

How diffucult is it to change the ignition coil pack. Is this something for a real mechanic? And about how much??

There is a way of testing the coil packs with an ohmeter. If you have one let me know and I will post the procedure. I believe there is only 4 screws securing each coil pack. And an electrical connector on the side. You should have 2 and they are right at the front of the engine. Make sure you replace the one that is messing up not both of them. On the top it will have the numbers of each cylinder it corresponds to. Just make sure you label each spark plug wire before you pull them off.

The code you have for the fuel is for the left bank of injectors. So that should help. The pressure on the fuel system with the vacuum hose attached is 30-45 psi and when the vacuum is unhooked 40-50 psi.
Let me know how it goes.

V8? :confused: 5.0? :2cents: (A lean code could be the cause or a effect of the misfire!) :feedback: It is a 5.0 right? :naughty: (I've been up too long I think I'm haveing a mental shutdown :silly: :screwy: because I can't for the life of me remember whether the 5.0 or 4.6 sohc went into the 01 Exploders :banghead: (think 02 for the 4.6!) I'll get some ZZZZZZs and get back to you when I can think! :tongue: ) :sleeping:

V8? :confused: 5.0? :2cents: (A lean code could be the cause or a effect of the misfire!) :feedback: It is a 5.0 right? :naughty: (I've been up too long I think I'm haveing a mental shutdown :silly: :screwy: because I can't for the life of me remember whether the 5.0 or 4.6 sohc went into the 01 Exploders :banghead: (think 02 for the 4.6!) I'll get some ZZZZZZs and get back to you when I can think! :tongue: ) :sleeping:

The 01 has a 5.0 Ohv V8. The Fuel code is not a specific code for anyone cylinder just for the left bank of injectors. So you might be right but in my experiences the symptoms he is having point to ignition problems. But I would recommend testing the coil packs before you have them replaced just in case. Also I would recommend you get this fixed ASAP as running an engine lean can cause serious damage.

:iceslolan OK I'm back! Now that the fact its equipped with a 5.0 is verified (and my brain seems to be intact now! :naughty: )I may have some useful info this time! The most common cause of a misfire in this application is voltage leakage from the plug wires from heat damage or age related deteriation. Also because of the coilpack's design the mifire code may not be caused by #7! In my exsperiance the concern is usually in the proceeding cylinder pair in the fireing order, but there is a way to pinpoint the offending cylinder. While the engines running disconnect each plugwire one at a time (don't get zapped!) and check for a lack of engine response (weak cylinder), weak or no spark (bad coil), or a very strong spark (bad plug, bad wire). Also, BEWARE of the Bosch platinum series plugs! Your coils are open loop design meaning when the coil fires the secondary voltage passes through the plug gaps in 2 cylinders, each with opposite polarities (plug 1:center to side. Plug 2: side to center) Bosch platinum tend to be biased to flow in one direction which can cause weak, no spark, misfire under load conditions, and coil failure. GOOD LUCK! :sleeping:

:iceslolan OK I'm back! Now that the fact its equipped with a 5.0 is verified (and my brain seems to be intact now! :naughty: )I may have some useful info this time! The most common cause of a misfire in this application is voltage leakage from the plug wires from heat damage or age related deteriation. Also because of the coilpack's design the mifire code may not be caused by #7! In my exsperiance the concern is usually in the proceeding cylinder pair in the fireing order, but there is a way to pinpoint the offending cylinder. While the engines running disconnect each plugwire one at a time (don't get zapped!) and check for a lack of engine response (weak cylinder), weak or no spark (bad coil), or a very strong spark (bad plug, bad wire). Also, BEWARE of the Bosch platinum series plugs! Your coils are open loop design meaning when the coil fires the secondary voltage passes through the plug gaps in 2 cylinders, each with opposite polarities (plug 1:center to side. Plug 2: side to center) Bosch platinum tend to be biased to flow in one direction which can cause weak, no spark, misfire under load conditions, and coil failure. GOOD LUCK! :sleeping:

He has already replaced the wires and plugs. But he did not say what brand of plugs he put in. The only other obvious thing is the coil. And by the way from experience don't try unhooking the plug wires while the engine is running. It doesn't tickle when you get shocked and your arm goes numb for a while too.

I am having the EXACT same problem. Autozone told me that it was my 7th Spark Plug miss firing.

Did you ever get your problem resolved?

I am having the EXACT same problem. Autozone told me that it was my 7th Spark Plug miss firing.

Did you ever get your problem resolved?
WHOA !!! Bosch ?? I just put in Bosch Plat. plugs and the engine IS pinging pulling a hill at freeway speeds...SO are motorcraft plugs the way to go??

WHOA !!! Bosch ?? I just put in Bosch Plat. plugs and the engine IS pinging pulling a hill at freeway speeds...SO are motorcraft plugs the way to go?? With fords motorcraft is the best option.

With fords motorcraft is the best option.



THANK YOU!!!

Personally I don't care what car you drive... I still would NOT put Bosch spark plugs in them. But that is just me. and I definately would NOT unlplug a spark plug wire while the engine is running on a car with coil packs. Does anyone know if the coil packs are interchangealbe?? I was thinking if they are you could swap them and reset the codes and drive it to see it the trouble code changed to a misfire in a different cylinder, if so I would think it would be the coil pack

Personally I don't care what car you drive... I still would NOT put Bosch spark plugs in them. But that is just me. and I definately would NOT unlplug a spark plug wire while the engine is running on a car with coil packs. Does anyone know if the coil packs are interchangealbe?? I was thinking if they are you could swap them and reset the codes and drive it to see it the trouble code changed to a misfire in a different cylinder, if so I would think it would be the coil pack

That is a good idea ! I would also find a salvage yard (should be alright) and give that a try. I did replace Bosch to Motorcraft platinum wire plugs. suppost to be good for 100k... we shall see. Let us know if you swap coil packs.

Cheech: ... Here man, hold this wire while I crank it over

Chong: ....Yeah, okay man, go ahead....

Personally I don't care what car you drive... I still would NOT put Bosch spark plugs in them. But that is just me. and I definately would NOT unlplug a spark plug wire while the engine is running on a car with coil packs. Does anyone know if the coil packs are interchangealbe?? I was thinking if they are you could swap them and reset the codes and drive it to see it the trouble code changed to a misfire in a different cylinder, if so I would think it would be the coil pack
Hi Yes, the coil packs are enterchangable. The running lean could be a symptom of a vacumm problem and could affect the the cylinder misfiring, however it wouldn't set a misfire code unless the ignition system misfired or the injector misfired.
I too wouldn't pull the spark plug wire off unless you had spark plug pliers. look on the number seven runner on the intake to see if the are any vacumm ports coming off it.