stwojay

My engine has developed a new ticking/knocking sound that has me pretty paranoid, so I'm here hoping someone has an idea what the source is. I'm planning on taking it to a shop to get it properly diagnosed but I'm curious to hear everyone's opinion on this matter.

My oil level is good. I check it religiously because I've spun a bearing in the past. I've pulled one coil at a time to see if the sound of the ticking changes but it sounded pretty consistent throughout this test. Also, the frequency of the ticking feels too high to be a mild onset of rod knock. I did the screwdriver to the ear test on the idler pulley and tensioner pulley. The idler was silent but the tensioner bearing was making some noise. It's hard to tell if the sound is coming from the top end or the bottom end. I got a valve adjustment done about 20,000km ago from a reputable shop as well. I'm hoping I can get around to running the engine without the accessory belt to see if the noise goes away this weekend. I've also listened to videos of the TCT noise and I don't think I have this issue.

Does anyone have any ideas what it could be? I do realize it's hard to make a proper diagnosis via a youtube video. In the video, the ticking is most pronounced at about the 23 second mark when the revs fall back to idle.

Youtube Link

windhund116

It does sound like a rod knock. You pull the accessory belt and see if you get the same knocking noise?

How did you spin the bearings, the first time? What was done to fix it? Were all the rod bearings checked for tolerance, at that time?

stwojay

Thanks for the reply. You could be right about rod knock but to me the frequency of the knocking is too high.

This engine was purchased used and swapped in.

I haven't had a change to pull the accessory belt yet to see if the noise goes away.

Jah2000

I can't really hear the tick/knock sound speed up as you revved it.. so I don't think it's rod knock. Sounds more like valvetrain. Irdk.

windhund116

IME, rod knock is noticeable on deceleration, not acceleration ---- as the engine returns to idle, from a quick throttle blip.

To test: pull each coil connection, one-by-one, and listen to the engine at idle. You should hear a lessening of noise, with one particular coil disabled. This is the rod that may have too much tolerance.

Jah2000

I had rod knock on an old SR back in the day, before it went KaBoOm. It went from mild in the garage, to worse, to even worse on the street, then finally sent a rod through the block after giving it a little gas. You can def hear it both accel and deceleration

Slowcrash_101

That's not rod knock. Probably just loose valves.

vasquezgno

I think a rod knock would sound with acceleration as well. I would do as guy up there and recheck valves.

windhund116

Best video I could quickly find with rod knock. You can't always hear the knock as well on engine rev-ups, maybe due to engine and exhaust noise. But, when it returns to idle (esp after quick blips), you hear the distinct tapping. Starts around 40 seconds into the video.

Just pull each coil connection, one-at-a time. Usually, the knock is associated with one (maybe two cylinders). Pulling those coil connections will change the rod noise.

https://www.youtube.com/watch?v=CFoOgdMqUoQ

http://www.youtube.com/watch?v=CFoOgdMqUoQ

windhund116

I'm more familiar, with rod knock, working on bikes.

Here is one. Starts around 40 seconds, also:

https://www.youtube.com/watch?v=C9dQ03e94ig

http://www.youtube.com/watch?v=C9dQ03e94ig