I got a check engine light and the code read P0018, I went down the list off possible issues and found my timing is off by one tooth by pulling off the passenger side timing cover and inspecting.

The timing belt/wp was replaced 5 years ago at 103K miles by me with new tensioners and pulleys, all OEM Toyota parts. It now has about 169k.

My question is what may have caused this so I can fix it from happening again?

My guess is maybe the tensioner has gone bad but it would seem premature for an oem part. Is this a common failure?

At this point I’m debating if I should just fix the timing and leave all the parts till till the next to/wp service or replace all the tb/wp parts earlier than anticipated.

I haven’t taken everything apart yet, when I do is there a way to test the tensioner or tell if it’s gone bad?

Thanks!

My guess would be it skipped a tooth. If it was me I would buy the Aisin timing kit and do it all over.

I also so this thread: P0016 and P0018 V8 VVTi 2005 Sport

Assuming all else is good, it would seem that a bad tensioner is the only thing that would cause this IMO. Not sure how you could check the tensioner to be sure it is good, it may show that it has tension but is it getting weak and going into some kind of harmonic at times that causes it to momentarily loose tension and allow the belt to get loose for a few revs? Who knows, but I think I would definitely replace the tensioner unless you find another cause.
Please keep us posted

I just saw a video where someone who lives in the Eastern States had a small mouse or something make a home next to the passenger side cam wheel of their Tundra v8. The animal got spun around the cam wheel and caused the timing belt to slip a tooth. Not saying you definitely have a mouse in there, but its something worth checking out.

Thanks all for the insight. After mulling it over, I think the only way to go is to replace TB/WP tensioners and pulleys. No point doing all that labor to put back old parts.

At this point I can’t get a good look an anything till I get the fan out, drain the radiator to move all the stuff out the way. I’ll check for rodents as well.

Quite disappointed that I used OEM parts and still had a failure. We’ll see how it goes. I’ll be sure to post my findings.

Just want to post an update so it may be useful to someone in the future.

It took me a while to finish the job since I jacked up my back doing yard work and had to wait till it healed up enough to get in the engine bay.

I did a full TB/WP job with all new OEM pulleys belts etc. While I was in there I replaced a noisy power steering pump and the alternator with oem remanufactured one since it was already out. I figure it would give me some piece of mind on my big road trip next month.

I still have no clue why it skipped, only thing I can think of is a premature failure of the oem TB tensioner I put in there 5/6 years ago. Old belt looked good along with everything else I pulled out.

Torqued everything to spec and topped it off with Toyota coolant and took a long drive to the beach and everything is running smooth now. Fingers crossed it stays that way.

Anymore issues? I got the code for the other side today. P0016

No issues since! Sorry for delayed reply, don't get on here much.