Engine is shaking, please help

[BlackNGoldRules]

I have a 2000 Ford Ranger 3.0 6 cylinder extended cab. Anyway, I started having a problem with my engine shaking about a week ago. Figuring maybe one of my pistons wasn't firing, I changed out all the plugs and wires. That didn't work. Had my mechanic put in a new fuel injector. It's still shaking. It mainly shakes at idle and shakes a little bit worse when I first start to hit the gas. Once I'm driving and have the gas pushed in a good ways I don't notice the shaking nearly as much. Do you guys have any ideas what this could be? Even my mechanic is stumped right now, especially after putting in a new fuel injector which he thought would solve the problem, which it and changing plugs and wires did nothing for it. It doesn't stall or anything, just shakes pretty good at idle mainly. Thanks for any advice.

 

[IZwack]

Is the RPM fine at idle when its shaking .. or does the engine feel like its missing (kind of like if the timing is off a little) or about to die?

 

[BlackNGoldRules]

The RPM feels fine to me at idle. It's not stalling or anything and the check engine isnt coming on. I just went out and started it up and it feels even worse now than it did earlier. Seems to be worse when you first start it up and then gets a little better after running for a while. But it just shakes at idle, shakes even worse when you raise the RPM a little and then it almost goes away when raising the RPM a lot when maybe driving it about 35mph or more.

 

[sparkyXplorer]

Similar thing was happening on my friends trans am, did things like plugs and wires also (needed them even besides the shaking) but for him the problem ended up being that a little rubber tranny mount like ripped in half so the whole motor/trans liked to move.

So one idea
Check out motor and trans mounts and make sure they are still good

 

[BlackNGoldRules]

Well, I havent been on here in a week and a half so I thought I'd give an update on my truck and hopefully get more ideas from you guys. Well, my truck's check engine light is now coming on and flashing from time to time. Ran a diagnostic on it and it came out PO303 which is the 3rd cylinder is misfiring. Already changed all the plugs and wires, changed the coil box, put fuel injector cleaner in it, changed the fuel injector, pulled off the vacuum hose and sucked some seafoam into it, and it is STILL misfiring at that cylinder. Again, mainly does it at idle. Oh yeah, did a leak down on it and it came out about 15 to 20% which I was told is a little high but fairly normal for a truck with as many miles as mine has which is 106,000 now. Now, someone told me to check and see if it's either the mass airflow sensor or the sensor near the harmonic balancer. Could either of those be causing a misfire in just one cylinder? And wouldnt the diagnostic have picked that up instead of just giving me the PO303 code? I did notice that the spark plug for that cylinder was wet when I looked at it this morning. Is it getting flooded somehow in just that cylinder? Any ideas from you guys would be appreciated. thanks.

 

[Tbars4]

..just a thought but could it be a faulty or loose coil pack??? i would also pull that wire and inspect it as it may be faulty, arcing, or even not plugged all the way in...
...and just out of curiousity, have you lost any fluid from the radiator???

 

[firedrow]

I had a similar problem with my 99 Ranger. It's a 3.0 V6, and my engine was shaking real bad. Like you we replaced wires and plugs, but found out the injectors were going bad. I lost 5 injectors while this problem was going on. We replaced them as we found them dead, that took some shake out but not much. It was like the engine was misfiring. So after about a week or so we decided to tear down and overhaul it. We found one of my pistons was scored bad. I had gotten the truck from my grandfather who let it sit for less than a year. Well I put E85 in it instead of 10% ethanol like he had (yes it is a flex fuel truck); well the regular gas left some buildup and the E85 was burning hotter and burning it all off. My engine wasn't used to it and left one piston to score it's chamber and all the metal flakes were balling up my injectors.

 

[Peteyscn24]

One of my buddies had a problem very similar to this. He doesn't know anything about engines, but what i took from him was that it was something with one of his cylinders or pistons. I think it ran him around $500 to get fixed including labor.

 

[rookieshooter]

Wet spark plug? Give it the old sniffer test and see if it smells like gas. Also pull that spark plug and and see if your getting spark from wire to bare block. Might have to insert a bit or metal rod in boot. Hold about 1/2", crank engine and have someone see if your getting spark. Seems to me if it is gas that's on spark plug then your having ignition problem.

 

[rookieshooter]

Well, any updates?

 

[Peteyscn24]

my buddies problem was actually the fuel injector also. Not sure what your problem is.

 

[bridgetroll]

i had this problem with my 2002 expedition. code scan gave cylinder 1, bank 1 mis-fire along with lean fuel mixture. had to change the o2 sensor located upstream of the left catalytic converter. stopped all codes from appearing and corrected the shaking and rough idle. hope this helps.

 

[dmac0923]

just a thought, if its just that one cylinder. are you loosing any coolant in your resovoir?? i had a similiar problem in another vehicle (not ranger) where i was getting a misfire in a cylinder. turns out my head gasket was leaking just enough to drip coolant into that cylinder overnight.

it was the worse when i would start it up to goto work....the motor would shake and idle horribly.

as we know water doesnt burn, and that would cause the misfire.

just something to keep in mind. if your loosing coolant and its not leaking on the ground.