Engine Light and Knocking Sound

Yours has a vacuum pump. Common item to become noisy and it makes a clackety racket when it starts to. The noise will be at the rear right side of the engine.

“Taco tick” is all too generic to describe a noise and will never lead anyone to any real diagnosis. Somehow that has become what everybody calls everything resembling ticking. There are all sorts of different noises these engines make, and they are all ticking of sorts, but they’re all different. Sometimes it’s a lifter not pumping up and smacking the cylinder head, others it’s a vacuum pump on a trim that has one, the direct injectors and injector cleaning cycle are noisy, etc.

Yours to me sounds like the pump. I’d look up some noisy vacuum pump videos and see what you think.

 

that’s exactly it. you’re a godsend.

 

The part number is 29300-31060 if you decide to replace it. Not sure how much the noise represents imminent failure, there are a bunch of them making racket on here and I don’t hear of many actual problems, but I would probably want to change it in the near future.

I miss the days where engines had their own vacuum supply at the intake manifold naturally and didn’t instead require a fussy $500 pump to create vacuum. Things like Atkinson cycle and turbos have made manifold vacuum a thing of the past.

 

im definitely going to replace it ASAP. the noise has been driving me insane. thank you so much for your help. do you know if it’s easy to get at? i feel like they make everything a hassle to reach in cars these days.

 

I haven’t worked on one, but it’s way back there and so I don’t feel like it will be “easy.” Mostly working blind and by feel. The coolant bypass hose will be in the way so you’ll need to remove the bolts for that.

I believe the FSM suggests removing the transmission mount bolts and lifting the transmission an inch or so which tilts the engine forward and makes it a bit easier to get at the back of it.

This photo shows the vacuum pump circled. You can sort of see the bypass hose blocking it.



This photo is of a non vacuum pump engine, but shows the hose in the way more clearly. What you see circled where the pump would normally be is a block off plate. TRD Off-Road and Pro have the block off plate because they use different brake boosters that don’t need vacuum. So no vacuum pump on those.

 

i owe you a beer

 

Here is the procedure for replacing the pump.
https://static.nhtsa.gov/odi/rcl/2018/RCRIT-18V211-7735.pdf

The procedure mentions: "Apply sealant to three or more threads of the tip of 1 NEW pump housing bolt. Standard: Toyota Genuine Adhesive 1324, Three Bond 1324 or equivalent thread sealer (not thread locker)."
This Toyota Genuine Adhesive 1324 sealer (part#08833-00070) is very expensive if you can find it so here is a cross reference chart from Toyota for an equivalent 1324 sealer.
https://attachments.priuschat.com/a...6863_0_Toyota_Adhesive__Sealant_Cross_Ref.pdf

I hope this is helpful.

 

The Toyota number you wrote, and comparing to second link you provided, is Red Threadlocker. Never take the bolts off next time, all permanent.

 

I found it odd that the pump replacement procedure says not to use threadlocker but the equivalent to 1324 is a red threadlocker.