Hello!
I recently purchased a 2018 Toyota Tacoma. It is the SR5 3.5 V6 Auto. It currently has 29,000 miles. I have noticed once it's warmed up, it make a pretty loud "knock" sound. It's noisy enough to hear in the cab when idling. I took it to my nearest Toyota dealership and they said it was normal. They told me it was the high-pressure fuel pump. Research has also shown it could possibly be a faulty vacuum pump? Anyways, it just doesn't sound right to me. Has anyone experienced this? Thank you!
Unfortunately similar sounds exist in newer 4runners. Scotty has a video on that. The dealers say it is normal since the new one makes the same noise but it is because the engine has some issues. Hopefully it won’t end in engine issues down the road.
It's actually a faulty vacuum pump that is currently under recall. Just wanted to update.
Hope it fixes the issue.