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Ford Repair/ford ranger 3.0 v6 misfire


Robert G wrote at 2009-06-13 10:56:50
I have the same issue with my 3L 204 Ranger, have changed plugs, wires as well as the coil.  No improvments.  Was told maybe a vac leak or PCV valve but not changed it yet.  Chk engine always says cyl 5 misfire.  Starts always when at idle, generally runs smooth at speed.

Jim S. wrote at 2009-08-01 03:10:37

Wow, our problems are IDENTICAL. I had the same compression problems and eventually took it to a local shop whereby they machined the heads. Worked great for 8 months until tonight when my check engine light came back on. I'm going to have the codes read back and hopefully I won't be spending another 1300 bucks for this job.

If I do, I will be visiting a Dodge or Toyota dealership soon. Never had a problem with my previous Ranger but this Ford business is getting ridiculous.  

Pappaw Anders wrote at 2009-09-14 12:13:12
This is the first time I have ever posted to a "car repair" forum, so please bear with me as I ramble on.

I had the infamous Check Engine light on my 98 Ranger V6 3L due to an O2 sensor.  I drove it like that for about 2 months (new job, money tight, etc.) until it could be determined the specific one that needed replaced (Bank 1, Sensor 1 - Front Sensor, Passenger side).  

About 8-10 days after the sensor was replaced, the engine started clattering really bad (like valves on REALLY bad gas) and lost power to about 40 MPH on the floor.  I couldn't see anything wrong on the gauges or lights, and didn't see anything obvious when I looked under the hood.  I remembered reading about how a bad O2 sensor could burn the plugs, so I pulled them.  Only 2 had ANY of the center electrode left in the insulator.  I changed out the plugs and wires and cranked her up.  There was a very pronounced miss that shook the whole truck.  I figured it was the computer still trying to compensate for the old plugs.  I drove it awhile to see if the computer would reset and smooth things out.  At speed, the miss disappeared, only to return when the engine returned to idle.

About 2-3 weeks later, the oil pressure gauge started bouncing top to bottom, then bottomed out and the engine died.  It cranked for a bit, then finally started.  Everything looked and felt normal, right down to the miss that hadn't gone away.  The oil pressure dropped out 2-3 more times within a couple of miles, so I ran an engine flush and changed the oil (after that, the oil pressure gauge stayed steady).  I started it up and the clatter/knocking smoothed out.  Even the miss was barely perceptible.  I figured it was fixed and started for home some 30 miles away.

About 2 miles down the road, it seemed to be loosing a bit of power, but I blamed it on the changing up down grades of the road.  At roughly 10 miles, power dropped to nothing and the clattering started up again with a vengeance.  I pulled it over immediately and shut it down.  I had it towed home and I will be digging into the engine today to find out what happened and to see if I need to start saving for a new engine (~$1500-$2000 shipped, around $3500 if a shop does it).

I have read numerous posts recently that link the same knocking/clattering description (and drop in oil pressure) to an oil change.  I would have been very skeptical of the accuracy of the information if I hadn't experienced the same thing myself.  When I find out what happened, I will try to remember to post back here so that maybe someone else can benefit from it like I have from yours in the past.



Tom wrote at 2014-07-29 17:45:46
You need to check your pcv valve connector assembly, you might have a cracked tube and replace grommet. It should snug tight.

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mark henson


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