Knocking crankshaft in idle after engine swap

So my number came up for new engine on my ‘22 about 3 weeks ago. After much hesitation and deliberation and with no issues on my old engine (yet), I decided to go for it for the peace of mind. Overall, I’ve been quite happy. The replacement was done in 2 days and they were able to work around all of my mods. The new engine definitely seems to run smoother while driving with a noticeable reduction in throttle lag.

Initially there was a slight oil smell on startup that resolved after the first week and no leaks. But I've also noticed an intermittent knocking during idle and when the alternator kicks in that I expect from the crankshaft of an old beater car or truck, just quieter. I’m 75% sure it wasn’t there before. It’s not obnoxious… just… less than perfect. I’m thinking something possibly wrong with the install, bearings, or timing chain.

I contacted the service manager I’ve been working with and he stated that if the sound is intermittent and there are no dash warnings that I’m probably being over-analytical and to maybe settle in to it a little more but he’s happy to have the mechanic look. Problem is, if they don’t find anything, I have to pay $139 plus tax for the search or if there’s a problem with a non-replaced part. It’s covered if there’s a problem with a replaced part.

Has anyone else had this? What are the chances it just needs the timing belt adjusted or something ‘small’ like that? Just frustrated I traded a perfectly good old engine (so far) for the peace of mind of an engine that wouldn’t brick on me… buyer’s remorse maybe.

 

Buyers remorse.


You dont have a timing belt.

Even if it was something "small" your computer controlled twin turbo 10 speed auto would indicate a problem.

Enjoy your new engine and your truck.

 

Definitely do not think about that knocking sound. It's virtually a brand new engine.

 

You have to find a way to consistently reproduce the issue to show it to the dealer.

I wouldn't go back to the dealership that did the swap originally because they will probably not get paid for any of such diagnostics and troubleshooting because Toyota will say that they messed up during the install and won't pay them to fix their own issue. They'll just get rid of you and say it's normal and also charge you the diagnostics fee so you don't come back to bother them again.

Go to another dealership, your goal is to have them write in notes that this noise is not normal and they need to diagnose further. Another dealership can potentially charge Toyota for diagnostics and fixing of this because they're not the ones did the engine swap. First dealer will do everything possible to blow you off


If they say it's normal then try calling Toyota engagement to explain this mechanical noise wasn't there before and go to the second or

 

Thanks all. Very helpful to have thoughts and advice that are more even keeled to keep my over analytical mind from imagining the worst. I was not aware there was no timing chain on these. I’m not afraid to turn a wrench but my engine knowledge is definitely lacking.

 

Just setting the record straight. The V35A turbo charged V6 does not have a "timing belt" like the 4.7L 2UZ engines in the gen 1 Tundras. It does use timing chains just like the 5.7L 3UR or 4.6L 1UR V8 engines of the gen 2's. (early gen 2's were available with the 4.7L 2UZ also).
Now the slight "knocking" sound may actually be coming from the transmission as some here have reported when idling in park.

 

ah ha! and now I know those terms aren't interchangeable. Thanks all