My 2016 Camry just passed 200k miles. For about the last 20k miles, I notice a slight ticking noise from the engine when the engine is cold. It does not go away until the car has been driven about 20 minutes, even though the engine temperature has reached normal in the usual space of time. I have a stethoscope, and I could use it, but that would only confirm the location of the sound, which I strongly suspect is a lifter.
I used the motor flush stuff that I can't remember the name of (not seafoam)-the stuff you put in & run the car for 15 minutes-could I have dislodged some crud into a new location?
I just switched to Valvoline High Mileage oil, and it didn't seem to matter (longshot anyway). My used oil has never looked very dirty.
I thought about tackling a lifer adjustment DIY, but it looks like something I could screw up. Is it worth taking to a dealer for valve adjustment? Expensive? Do us a favor and don't reply with:
1. "200K? Just get a new one!" (Dealership Answer)
2. "Run it into the ground! You got your money's worth already!"
Thanks.

 

A lifter adjustment at this point would be fine and prudent. Your car has put in the work so why not have it checked?
Is this a four cylinder? Are you mechanically inclined or do any of your own work? Adjusting valves tolerances usually only requires some feeler gauges, a couple of wrenches, and a new valve cover gasket.
Lifter 'tic' is common on high mileage engines and is typically not a problem BUT- it is not like I have actually heard how loud your tic is.
To sum it up, if you like the car and are going to keep running it for many more years--> fix/adjust it.
You don't care and are ready for a new car (hopefully a Camry)--> Run it.

 

I am pretty mechanical, but I used to know how to do this 40 years ago when lifters were mechanical. We used to do this with the engine running, using go/no go feeler gauges. By looking up videos, I see that these lifters have a little drum-shaped "hat" over the valve spring, and adjustment is achieved by inserting shims. . Also, this car has a timing chain, not a belt. In the videos, the have the chain undone, and the turn the camshafts with a wrench. I don't want to mess with the chain, and I doubt that I can turn this engine with the nut on the crank. I'd say this job is slightly out of my depth. Any idea what a dealer might charge me for this?

 

I'm honestly not sure what a dealer would charge. I hear you about adjusting lifters, the last lifters I adjusted were on a '95 Accord 4 cylinder, no shims for those either, just feeler gauges and and nuts.
I don't blame you for not getting into it.
Let us know if you find out.

 

Engine model?

You can narrow down the noise area as in lifters or timing chain, VVTi, etc. A worn VVTi unit can rattle for a time after engine start up.

Toyota typically uses shims to adjust the clearance. Its not a big deal to adjust but you need a tool to remove and replace them plus the right shim. Toyota has a chart listing which shim part number to use to obtain a set clearance given the current shim in place.

How bad is the ticking! Might consider using a higher weight engine oil. Toyota calls out oil based in part on CAFE requirements. One can solve a lot of issues on older engines by using a higher weight oil.

 

I am now beginning to believe that the noise is caused by the VVTi gear. I have the characteristic start-up rattle, and the slight ticking lasts about 15 minutes, even after the car is warmed up to operating temperature.
I have watched several videos about what to do about the VVTi rattle, including taking the cover of the gear off and stretching the spring. The consensus seems to be that the locking pin gets dirty and fails to lock the gear for a couple of seconds (startup rattle) due to sticking. I had doubted that there would be any dirt, since I am diligent about oil changes, but now that my car is using oil, the crud factor is probably higher. The little filter for the oil supply to the gear may be dirty. I watched a video where they crank the engine with a dirty filter and a small amount of oil bubbles out lamely, then they clean the filter, and a 2" fountain comes out!
Oil weight. My manual calls for 0W20 oil. It also says that 5W20 can be added in a pinch, but to change back to 0W20 on the next oil change. Is the sole reason for using 0W20 for a small uptick in gas mileage? I assume that by "a heavier weight of oil" you mean 5W20? Thanks.