Need advice

[ekrampitzjr]

My 2011 2WD Ranger with the 4.0 SOHC and 5R55E transmission sometimes has a faint rattle-like sound on acceleration. When I hear it, it can be when the engine is cold or hot, not just when cold. It seems to show up at around 2,000 rpm or so, just before the transmission shifts into the next higher gear.

Other times I don't hear it at all. The engine idles very quietly and has plenty of power. There is no rattle at idle.

I cannot actually pinpoint this rattle as an engine noise, meaning it's not clear where it's coming from. I hear it with my right ear. Possibly it could be an exhaust-system or other noise.

The truck has 173,000 miles. I had the tensioners replaced as a preventive at about 105,000. I have been using Amsoil synthetic oil with changes every 10,000 miles (this is the Signature oil said to be good for 25,000 miles). The rattle started about 10,000 or so miles ago. It has become only slightly more noticeable since then.

Generally the truck gets 93–octane premium gas as the engine seems to run best and get the best fuel economy on premium (and this is what the engine was designed for in the first place). I also run fuel-system cleaner occasionally. This suggests that detonation and clogged injectors are not likely to be the source of the noise. Fuel economy is still typically around 20–22 miles/gallon in highway use.

Should I bite the bullet and figure on getting the timing chains, cassettes, etc., replaced? Or what do you think is going on?

I know most of the 4.0 SOHC owners are paranoid about the timing-chain system and noises. That would include me.

Thanks for your advice.

 

[sgtsandman]

Is this during heavier acceleration or when going up hill? I get it some times when I'm starting from a full stop or if I haven't shifted down to a lower gear, like I should.

 

[ekrampitzjr]

Is this during heavier acceleration or when going up hill? I get it some times when I'm starting from a full stop or if I haven't shifted down to a lower gear, like I should.

Mostly during normal (not heavy) acceleration from a full stop, including on a level road, when I do hear it. (Not too many hills out my way, though highway on-ramps are close enough.) Again, much of the time I just don't hear it at all, even when I try to replicate it.

 

[sgtsandman]

Mostly during normal (not heavy) acceleration from a full stop, including on a level road, when I do hear it. (Not too many hills out my way, though highway on-ramps are close enough.) Again, much of the time I just don't hear it at all, even when I try to replicate it.

If it isn't doing it often, then it is probably normal.