I have a 2010 Ranger 2.3 DOHC with 150,000 miles
Just recently it has had an overall lack of power and when shifting into passing gear the engine has a detonation/rattling sound.
Does this seem to be some kind of electrical/computer issue or could it be caused from a worn timing chain?
At idle, engine runs smoothly with no extra noises or issues.
Thanks in advance for any suggestions or information.

 

Could be a lot of things. Weak knock sensor, weak/slow o2 sensor, weak fuel pump, dirty fuel filter, clogged air filter, bad spark plugs or wires, bad coil and so on.

Have you done any routine maintenance on it lately? Spark plugs, wires, air filter, fuel filter, etc?

 

Haven't done any of that lately. I drive close to
100 miles a day. I change the oil every 3,000 miles.
I had to get a new battery a couple weeks ago. It must have shorted out internally or something with no indication it was going bad. It was very cold here and started fine all day. Shut it off for 30 mins, came back out to leave and it was just dead! Tested the battery and it showed it had a short. Installed the new one and it started right up.
The truck seemed to be low on power and starting to do what it is doing now before that but once that happened, I assumed it was a product of the battery issues. Now with the new battery it isn't better.

 

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Google: Ranger 2.3l IMRC problems

IMRC= intake manifold runner control
If it is not working or becomes disconnected you will notice a drop in power and it can rattle as well
This was a known issue on the 2.3l Duratec engines

It is vacuum powered and hoses can crack, and actuator arms at back of engine can come off

Timing chain on the 2.3l Duratec seems to be fairly bullet proof, don't see many, if any, posts about that on this engine


IMRC is used to get extra power based on Helmholtz resonance.
Since there were gas engines it was found that the length of the intake runner(tube) for each cylinder could improve performance in a specific RPM band.
Simply explanation is:
When piston is on down stroke, intake valve open, it is sucking in air, at the bottom of the stroke the intake valve closes, but velocity of air being pulled in is still there in the intake runner.
This velocity creates a rebound pressure wave in that runner when intake valve closes
That wave will again rebound when it gets to the other end of that runner
And the pressure wave travels back towards the intake valve
If it arrives at that intake valve when it is open again then it pushes more air into that cylinder
So mini-super charger, for free
The length of the runner determines how long it takes for the rebound, so what RPM range will get the benefit

IMRC changes the length of the runners in the 2.3l, so you get broader RPM ranger with that extra free boost

 

RonD, actually 2010's luckily do not have the IMRC. Ford got rid of that system on the 2004+ 2.3's along with that horribly expensive heated thermostat.

And yeah, I agree with Ron, the timing chain is pretty bulletproof.

 

dmlong54, if you are going to have this truck for a few years, I Highly recommend downloading the free forscan software from forscan.org and purchasing an OBD2-USB cable. I use this software on an older laptop on my 2003 and it works wonderfully. It will definitely help you diagnose your problems other than maybe fuel pressure although that would show up in other sensor's values.

If the engine is truly pinging then it's running a bit lean. Heck, it could even be a large vacuum leak (although that would be pretty apparent by the high pitched whistling noise you would probably hear at idle).

I would start with replacing the fuel filter if it has never been changed. That's assuming that the air filter, sparkplugs and wires have all been changed out within the last 10,000 miles.

Oh, and another thing; A few of the sensors can get gummed up with oil vapor blowby (which is pretty normal on these engines). I would recommend getting some sensor safe spray cleaner (MAF Cleaner) and cleaning your MAF sensor, MAP sensor and IAC solenoid valve.

 

OOPS, good call Soledad

 

Well, replaced the spark plugs, wires, air filter and fuel filter as well as cleaned the MAF sensor. Still has a significant lack of power....
Also hooked up an OBD II and CAN scan tool and it shows no codes.
Any other suggestions?

 

I would pull out the MAP sensor and see if it is gummed up. Just disconnect the wire and remove one screw. Then pull it up out of the intake manifold. I don't think that's the problem but it's certainly good to check.

Hmmm....I'm pretty sure that when you go WOT, the PCM doesn't take readings from the o2 sensors and uses a pre-programmed fuel map instead. And so if there's no power at WOT then the issue isn't the oxygen sensors. But it may still read from the knock sensor (not quite sure though). With that said, have you tried running a tank of 91/92/93 octane? You'd have to run two full tanks to make sure you are running nothing but high octane. If it seems better then it could be a pre-detonation issue.

You might also try disconnecting the negative wire on the battery and let it sit disconnected for 30-40 minutes. Then reconnect it and see if that changes anything.

It would be nice to see what your short term and long term fuel trims are. But you'd need Torque Pro or forscan for that.
And it would be good to see what your fuel pressure is during WOT.

Hopefully others will chime in.

 

Any quick direction as to the location of the knock sensor?

 

The knock sensor is round and is located on the drivers side of the block near the PCV valve.

http://s229.photobucket.com/user/spo...ensor.jpg.html