Ticking under load between 1900 and 2900 rpm.

Hey guys,
I have an 06 4.0 with the 6 speed. Truck has always had a little bit of the taco tick at idle but nothing that was not normal. Went to drive the other day and when first taking off I started to hear a tick only audible with the windows up. It comes on under acceleration at around 1900 rpm and tapers much quieter around 2900-3000 rpm. Sort of sounds like an exhaust leak but not really. Detonation? It does not make the sound at idle, or in neutral being reved. Motor is absolutely quiet when being started with no ticks or rattles. I run mobile one 5w-30 and a Toyota filter and change the oil at 4-5k miles. I’m at about 1000 ft above sea level. I did look at the timing degrees on my scan tool and it said 28-29 degrees total around 2,000 rpm. I know the timing chain is not common on these motors. Any ideas? My next thought it to fill up with 91 octane as that’s the highest octane I can source locally to see if it has anything to do with detonation. The truck has 188k on it. I’ve owned it since 161k.

 

Any luck?

 

Sure it is the engine? Throw-out bearing gets squeaky, and I can hear it sometimes in gear.

 

I just had 2 exhaust leaks (self inflicted) that I had recently fixed.

Small exhaust leaks will make a ticking sound and smaller ones will only show up under load.
If the ticking is exaggerated with more throttle, but tends to be quieter or go away when coasting, then its an exhaust leak.

It could be something else, but it might be worth it with the engine running to run your hand along the exhaust pipes and manifold (not touching it of course) and feel for any pinhole leaks. Even the smallest leaks you will be able to feel little puffs of air.

 

A tensioner going bad can do this when under load, but not while idling.

 

A leaky exhaust manifold will tick under load.

 

Thanks guys, no exhaust leaks and we finally had some weather in the 60s. Seemed to go away. I did find the drivers side cat support broke off the exhaust so I welded it back on. Seemed to take care of it. I also think that some of it was injector tick when it was very cold. (Below 30) seems to be running fine with now 193k and I have done some 5+ hour trips. Not too worried.

 

My Ranger was knocking a little for a few weeks on acceleration on the highway until I had the chance to replace the sensor. It wasn't a bad knock (the sensor was just failing - not failed). It's a very distinctive sound - not consistent like a "tick," more of a rattling like a can with a few marbles. And even then, in the case of the Ranger, it was mild enough that if you had the radio loud enough, you wouldn't even hear it.

My Taco (2TR-FE) has lifter tick when it's below freezing, and only on acceleration. When it first happened (mine is used), I thought I would have to adjust the valve lash (the only Toyota p/up I had previously was a '95). Then I learned that these have hydraulics, so then I thought "sh*t, I have to replace the hydraulics," then I learned that "Taco Tick" is a thing. So now I just let it warm up for a couple/few minutes when it's cold before taking off - problem solved.