Loud rattle at 4K RPMS+

chevrolet

#1

Okay so one night I was out w friends, having fun driving about 40-45 then someone tried to pass me I was like oh hell no and slammed on the gas it kicked down to second gear, 4K rpms, climbed up to 5.5k and shifted, well when it reached 5k it was rattling I heard a rattling noise. I can slam the gas all I want but it’s only rattling at like 4.5k rpms and above. It has gotten louder a littlest but not like CLANG CLANG it’s just like ting ting ting. Not too bad I can’t explain it, it’s like the engine is throwing around a little tiny metal ball at 4.5k rpms +. Any ideas of what it could be?


#2

Have someone check for a loose exhaust heat shield.

Tester


#3

It doesn’t rattle when I’m in park and I get it up to 5k tho, would that make a difference ?


#4

Yes.

In park, there’s no load on the engine.

In gear, there’s a load on the engine.

That changes the frequency to cause a heat shield to rattle.

What I’m wondering is, how are you able to rev the engine to 5000 RPM’s in park?

The computer has a rev limiter to prevent that from happening.

Tester


#5

I think the rattle is between the ears.

Nothing worse or more unsafe than some idiot that refuses to allow someone to pass the slower car and speeds up.

Yosemite


#6

Not on my truck. I have no redline, I do but no legit red marks on the tac-o.


#7

I was at work and didn’t explain, I was out with friends. we were just casually driving. about 5 people, 3 vehicles. If I didn’t want he/she to pass, I would just speed. But since we were being idiots I guess you call it, then yes, we were slightly racing :blush:. Thank you for your input.


#8

First off, check the oil level. The valve-train can make a rattling noise when it is a little oil starved. If you listen carefully at idle you can usually hear a faint rattling-like sound from the valve cover area even if the oil level is full. That’s normal. If not that, then there’s plenty of other stuff that can make a rattling noise in cars. Either something rotating (like the water pump, alternator etc) or just some fixed object rattling, like the hood latch or the exhaust system part mentioned above. There’s an electronics tool mechanics use called “chassis ears” which is used to diagnose this problem if difficult situations. The scientific reason something might rattle only at certain rpms is called “sympathetic vibration”. It’s the same reason when a trumpet player plays a certain note, only that note is heard.


#9

Thanks for this. I will have to go get it checked out somewhere. I don’t know where lol. I live in a small town and I might have to find a day i’m not in school and not at work or whatever. This info was really helpful. My oil is topped off, the low oil came on and usually when it does that it needs a quart of oil, I am going to get an oil change soon. It’s just spooky because after all what if there is something wrong with the engine lmao… I mean yeah nothing I can do about it, but I just need to have peace that it’s not the engine and that’s what I’m hoping for. And I don’t hear any rattling at idle. I have listened closely. And to what I said before, It cannot be the engine then because its only when the engine is under load. Thanks for all of the useful info.


#10

I’m going to upload a video tomorrow.


#11

great!
very courteous and safe way to behave!

+1, @Yosemite!


#12

Oh @Yosemite @thegreendrag0n. Y’all have never ever been young right? You’ve always been perfect in every aspect. That’s means you’ve never had fun, wanna share your ways that you’ve never ever did anything wrong in your life?


#13

You say the low oil light came on? And you’re used to it doing that, apparently, since you say it normally needs a quart of oil when the light comes on? Oh, hell no. :laughing:

Seriously, I’d check the oil frequently and make sure the low oil light never came on. Could well be the cause of the rattling noise if you see that low oil light very often. No idea exactly what the noise is (lifters, bearings, etc) but if it’s inside the engine, low oil could cause it both immediately and over time due to wear.


#14

nobody is perfect, but the behavior you described is endangering not only your life, but many others

do you expect any kind of encouragement or patting on the back for it?

and NO, even when I was young, I did not do THAT stupid


#15

If this is the vehicle in the persons other thread it has 275000 miles on it. He revs the engine thinking it will make the air conditioner work faster , he lets the oil light come on before adding oil so the chance of this vehicle lasting much longer is not good.


#16

@RainbowCamaro. Yes we all did stupid things when we were young…as everyone has done.

But we only learned what was acceptable and proper by someone pointing out our errors.
That is all that was done here…to point out how dangerous your practice can be…hoping that you see the danger in what you are doing.

Your tach ay not have a red line, but be sure that there is a red line for the engine, and the only way to find that point is to destroy the engine.
The electric pole in front of my home does not have a sign that says “Do not climb pole and lick the wires”, but does it really need one!!!

My truck has never been above 4000 rpm and it has 306,000 miles on it and still runs like a top.

If you want the engine to last…slow down!!!

Yosemite


#17

This post was flagged by the community and is temporarily hidden.


#18

No not regularly just one time in-between oil changes.


#19

Okay sir. Thanks for the words.