1992 Ranger / 4x2 / v6 / 4.0

I took my Ranger to a mechanic for a diagnosis, they couldn't identify anything (they checked for codes and found none) and they wanted to do a full engine tear down (I can't afford that).

When I accelerate into higher gears (Automatic Transmission) I start hearing this metallic clattering/chirping sound, (it sometimes sounds like mice). This only happens when I'm giving it some gas, for accelerating up a hill or just in general. I start hearing it around 40 mph and it becomes more pronounced at around 50-55 +. I can hear this through my dash, on the drivers side.

About a year ago I had a Cam Position Sensor code active and the sensor was replaced. I'm wondering if this is the camshaft synchronizer?

To be clear, I do not hear this sound when the truck idles.
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Other things to add (possibly related?):

Every now and then ( this doesn't happen every day). The Engine will surge upon starting and eventually the surging stops when I give it gas and get moving. I have been told my idling sounds normal and good (when It's not surging). I haven't noticed any surging after I replaced the thermostat (not sure if it was related). I recently replaced my thermostat which fixed some overheating and seepage issues, I noticed my temp gauge moving from the middle to bottom.

I have also noticed my ranger has developed poor fuel economy. I'm running through gas faster than normal.

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Anyways, I'm very curious about that metallic clattering/chirping sound at higher acceleration.

Any input is greatly appreciated and thank you.

 

Welcome to the forum

Are you sure noise is not heat shields or muffler rattle noise, you can use a rubber mallet or wood to bang on these to see if they make a noise

"Chirp" noise could be cam synchro most likely, do you still have the receipt for it to see what brand of synchro was used

Lower MPG can be old O2 sensors, they last 150k miles or 12 years and they run out of chemicals which causes Rich running, so lower MPG

Partially blocked exhaust can cause the noise and lower MPG, test with vacuum gauge, read here: https://www.gregsengine.com/using-a-vacuum-gauge.html

On cold start engine should REV above 1,500rpms then drop to about 1,100rpms, then as it warms up it will slowly drop to 750 with automatic
The ECT(engine coolant temp) sensor does that part, will it tells computer the temp and computer sets idle RPMs according to that temp

ECT sensor is a 5volt unit, only used by the computer
There is also a engine Temp SENDER, a 12volt unit, omly used by dash board temp gauge
These look similar but are not the same

Ranger temp gauge should be just below 1/2 way after full warm up, say 10 minutes
If it stays below 1/3 then new thermostat is stuck open or wrong one, if should be rated as 190-195degF, nothing lower, cooler will mean lower MPG

 

Today I was driving and noticed if Im cruising without pushing the pedal to hard, I dont here the noise. If I give it some gas, pushing the pedal about half way or to the floor, this tiny rattling noise occurs. The noise at one point sounded like it was electric buzzing. It's like 3 noises in one.

I recorded the sound with my phone but I can't seem to upload it. I'll try this again when I get to my laptop.

 

I doubt a recording will help, noises are very hard to ID even if you KNOW whats causing it, lol

 

I found out what the problem was.

I described my problem wrong. I may have perceived this sound as a small squeak but really it was more of a small snap,crackle sound.

My spark plugs are very bad and as I give it gas, the spark plugs were crackling. This would also explain my poor fuel economy.

 

Yes, arcing would explain the noise and the lower MPG, good find