2005 V6 ticks like a diesel when in drive, not when out of gear

My 2005 V6 (140k miles, timing chain set replaced at 95k) ticks loud enough to sound like a Cummins diesel under throttle when driving, but won't do it in park or neutral when I try to troubleshoot it. Gas mileage hasn't dropped since it started. I`ve checked the timing chains and tensioners, changed the fuel injectors, and checked for exhaust leaks. Any other things I should look for?

 

Seems like it is something in the vvt system, but it isn't throwing any codes.

 

Why were the timing chains replaced at 95K? That's really low miles for chains to go on a 4.0 unless oil changes were neglected.

Were the phasers and VVT solenoids done at the same time?
VVT screens cleaned?

 

Oil changes were missed, resulting in stretched chains. Block was flushed, and screens and solenoids were changed at the same time as the chains. Phasers were not.

 

Have you checked the oil level?

If that's good you may want to check the VVT screens, if the engine was sludged up they may be getting plugged again.

I have also read where a few people had the VVT solenoids cause the phasers to rattle when they weren't working properly.

 

Might be an exhaust shield rattling around. Get under the truck and tap on the heat shields, with your hand or a mallet, see if you can recreate the noise

 

Oill changes have been done religiously every 5 k miles since the chains were replaced. Pulled the screens and cleaned them at the last oil change. The only thing I can think of is to replace the phasers, but with no codes I'm not positive on spending $500+ on parts yet. If I have to, I have to. Just looking for any other hints before I tear it down again.

 

most mechanical things that make noises during rotation, like lifter ticks, do so at all RPMs, though may be louder or softer at different RPMs. If it happens only at higher RPMs and disappears at idle, I would not be starting with cam, crank, chain issues. You implied that if you rev the engine to higher RPMs in neutral, the noise is not there either. If true, that leaves out rotational noises and moves you to load related noises. Do you know what knocking sounds like? that sound is "somewhat" similar to a diesel. Does the noise favor heavy loads like acceleration or also in light load cruise? You want to be listening for noise frequency and seeing if it moves with RPM changes or is unrelated.

 

Its definitely throttle position/load related, not rpm related. Happens at around 20% throttle and up, does not happen without throttle input. For example, starts at 1100 rpm when acceleating going up a hill. Does not happen under compression braking up to 3500 rpm when going down a hill with no throttle input. It is there constantly under high speed cruise on the freeway at about 2000rpm.

 

I know you said you checked for exhaust leaks, but, did you check at the manifolds?

 

For what its worth I had a 2002 TRD off road with supercharger that made a ticking noise when in gear (automatic) but made NO noise in park, it Turned out to be a cracked flexplate.

see my old thread here

https://www.tacomaworld.com/threads/flex-plate-now-fixed.445998/

 

Pulled them both and replaced the gaskets. Exhaust leak was where I first suspected the issue was. Moved on to fuel injectors from there.

 

1) If you are driving with the tick and shift into neutral, does it stop or continue?

Does it have a rhythm to the tick?
2) If you driving slow does it tick slower than when you are driving faster? Can you hear the tick accelerate as you give it gas... In other words, is the tick in rhythm with rpm, mph, or anything else?

Never mind @Ghost411 Sorry, just saw you last post...

 

Ahh, ok. Hopefully it ends up being something simple.

 

Good thought, but it only does it under acceleration. It doesn't do it at idle at all. Thanks for your input.

 

Dows not do it at idle, even in drive. It ticks in time with the rpms above about 1000 when moving, but the volume increases the harder you step on the gas. Going up a hill from about 30 (at 1100 rpm or so), it gets loud but chugs until it downshifts. The it gets a bit quieter and the cadence increases with rpms. The volume increases with how hard you press the gas. If that makes any sense to you.

 

Remove the serpentine belt and run the truck for 4 minutes listening for the sound .
Dont run it for long as no water pump turning

 

Do you know what detonation sounds like? Some liken the sound to that of marbles rattling in a glass jar. Detonation generally only occurs under load and usually at heavy load. It often occurs when lugging or try to get the engine to produce high power at low RPMs, like before the trans downshifts. These engines have detonation sensors and should be retarding timing when it occurs to stop it, but that assumes all is working well. Not saying it is detonation, but given the symptoms it would make sense to have someone who knows what it sounds like to have a listen.