Brief Knocking While Reving From a Stop

[BierMeister]

Today my engine started making a knocking sound when the car was warmed up and the rpms were as low as possible at idle. It only happens when I rev from a stop in these conditions, and it doesn't last more than 1/2 a second. You could say it's only 5 or so knocks that I hear in quick succession. It also quiets down a bit when I'm holding in the clutch. I don't normally rev the car like this but there is another noise that I have been hearing for the past few days and I was trying to listen for it. That noise is a tapping that I only hear between 2k and 5k rpms. More so when the engine is cold.

It may or may not be relevant but I did a lot of maintenance two weeks ago:
- Oil and filter (kirland 0w20 and oem filter)
- trans fluid (motul gear 300)
- diff fluid (motul gear 300)
- air filter (k and n)
- brake fluid change

So far I've only checked the oil level because I have no idea what else it could be. The car only has 31k miles so I made an appointment with the dealer on Thursday and I won't be driving the car until then. I figured I'd post here and let you weigh in on it before then. Thoughts?

[x808drifter]

Do an oil analysis to help rule out internal damage.

[ermax]

The fact that it changes when pressing the clutch a little leads me to believe it could simply be the TOB. My TOB is on it’s way out and makes some rod knock like sounds at times too. On the other hand this could be an early warning that a rod bearing is on its way out. Anytime I’ve had a rod bearing fail I’ve gotten cold start knock for a few weeks followed by full failure.

[BierMeister]

I'd do an oil analysis if it was outside of warranty, but I'd rather not go down that rabbit hole right now.

Originally Posted by ermax

The fact that it changes when pressing the clutch a little leads me to believe it could simply be the TOB. My TOB is on it’s way out and makes some rod knock like sounds at times too. On the other hand this could be an early warning that a rod bearing is on its way out. Anytime I’ve had a rod bearing fail I’ve gotten cold start knock for a few weeks followed by full failure.

Are there cases of people's 2017+ TOBs failing still? I thought they were solid now.

[DarkPira7e]

Originally Posted by BierMeister

I'd do an oil analysis if it was outside of warranty, but I'd rather not go down that rabbit hole right now.

If you're in warranty, why are you sweating? Bring it to the dealer and have them diag. This is the only way to start warranty work if something is wrong and you intend to rely on your warranty to fix it.
Also, if you think an oil analysis is a rabbit hole, you should reconsider; it's seriously not. It's literally catching a little oil in a plastic container and shipping it.

[BierMeister]

Originally Posted by DarkPira7e

If you're in warranty, why are you sweating? Bring it to the dealer and have them diag. This is the only way to start warranty work if something is wrong and you intend to rely on your warranty to fix it.
Also, if you think an oil analysis is a rabbit hole, you should reconsider; it's seriously not. It's literally catching a little oil in a plastic container and shipping it.

I mean I'm not going to spend money diagnosing it with an oil analysis when I can just let the dealer figure it out. I have an appointment with the dealer on Thursday.

I'm only a bit nervous because I just did a bunch of maintenance on the car and think that somehow I could've messed something up. Even though the only thing I did with the engine was an oil change, and it's pretty hard to screw that up.

[DarkPira7e]

Originally Posted by BierMeister

I mean I'm not going to spend money diagnosing it with an oil analysis when I can just let the dealer figure it out. I have an appointment with the dealer on Thursday.

I'm only a bit nervous because I just did a bunch of maintenance on the car and think that somehow I could've messed something up. Even though the only thing I did with the engine was an oil change, and it's pretty hard to screw that up.

To be fair, an oil change may be one of the most simple jobs, but it's also one of the most important things in your engine as far as maintenance is concerned. underfilling (which is easily avoided by knowing how much oil your car takes)

could lead to issues if you drive the car before checking the oil level to be sure it's appropriately filled.

Hopefully the dealership can provide an accurate diagnosis of hysteria and there is nothing wrong

[Ultramaroon]

I bet you just hear the gearbox rattle now because of the fluid swap. Let it idle and listen while you press and release the clutch. Is that it?

[ermax]

Originally Posted by BierMeister

I'd do an oil analysis if it was outside of warranty, but I'd rather not go down that rabbit hole right now.
Are there cases of people's 2017+ TOBs failing still? I thought they were solid now.

My 2017 TOB is dying. It lasted around 30k miles. Apparently there are some even newer part numbers than the one I ordered that was supposed to be the fixed part. I saw another thread about the TOB where someone linked to an aftermarket bearing that is "oversized". I think I'll try that one next. Luckily this transmission is easy to drop.

[Jayden Norris]

Originally Posted by BierMeister

Today my engine started making a knocking sound when the car was warmed up and the rpms were as low as possible at idle. It only happens when I rev from a stop in these conditions, and it doesn't last more than 1/2 a second. You could say it's only 5 or so knocks that I hear in quick succession. It also quiets down a bit when I'm holding in the clutch. I don't normally rev the car like this but there is another noise that I have been hearing for the past few days and I was trying to listen for it. That noise is a tapping that I only hear between 2k and 5k rpms. More so when the engine is cold.

It may or may not be relevant but I did a lot of maintenance two weeks ago:
- Oil and filter (kirland 0w20 and oem filter)
- trans fluid (motul gear 300)
- diff fluid (motul gear 300)
- air filter (k and n)
- brake fluid change

So far I've only checked the oil level because I have no idea what else it could be. The car only has 31k miles so I made an appointment with the dealer on Thursday and I won't be driving the car until then. I figured I'd post here and let you weigh in on it before then. Thoughts?

Explore cold air intakes for scion on the website.

Almost any used car has valves knocking. Of course, this sound is not always critical. However, if a ringing knock appears when the engine is running at any speed, it is worth doing repairs.
Reasons for the sound of valves: wear on the camshaft housings,valve rocker,wear (it will click loudly);
clogged holes in the camshaft through which the oil is supplied to the rocker.
The main cause of knocking is the gap between the levers and camshaft cams. If the gap between the parts increases, the cam will knock on the rocker.Check the engine outlet valve. Check oil and oil pressure.

[NoHaveMSG]

Originally Posted by Jayden Norris

Almost any used car has valves knocking. Of course, this sound is not always critical. However, if a ringing knock appears when the engine is running at any speed, it is worth doing repairs.
Reasons for the sound of valves: wear on the camshaft housings,valve rocker,wear (it will click loudly);
clogged holes in the camshaft through which the oil is supplied to the rocker.
The main cause of knocking is the gap between the levers and camshaft cams. If the gap between the parts increases, the cam will knock on the rocker.Check the engine outlet valve. Check oil and oil pressure.

lol no. For starters, oil is not supplied to the rocker by the camshaft in an FA engine. The rocker pivot is a lifter so it really doesn't make noise if the tolerance is off on top of the fact these hold their valve lash very well as do most other modern engines.

[Ultramaroon]

Originally Posted by BierMeister

I mean I'm not going to spend money diagnosing it with an oil analysis when I can just let the dealer figure it out. I have an appointment with the dealer on Thursday.

And?