Rattle at High RPM's - Anyone know?

[YUOnDaGround]

When I stomp on the throttle and rev it up around 4-5k rpms there is a noticeable rattle from the engine. Enough to notice above the cool-air-intake and above my magnaflow exhaust.

Could this be the valves out of adjustment? Anyone had this happen to them before?

Thanks for your input.

2002 Tahoe
4WD
5.3L flex
164,000miles

 

[blueflamed03]

no SES light?

 

[YUOnDaGround]

none at all

 

[sumo]

have any missing tools in your tool box?

 

[JennaBear]

Sounds like detonation to me. Clean your MAF, and try finding better quality gas.

 

[waxworkz]

i have the same problem on my 01 suburban. sounds like its a cavitating pump almost. i notice it only at FOT. i thought it might be detonation but i'm not sure

 

[JennaBear]

Clean those MAFs! We see it time and time again, the MAF is the most important sensor on the vehicle, and can really cause some nasty issues.

 

[YUOnDaGround]

When you say better quality gas do you mean octane or gas station? As in shell over a bottom of the barrel no name gas station?

Also, I have cleaned the maf multiple times... However I will clean it again just to make sure. When I say multiple I mean 3-4 times in the last 2 months.

---------- Post added at 08:26 AM ---------- Previous post was at 08:23 AM ----------

i have the same problem on my 01 suburban. sounds like its a cavitating pump almost. i notice it only at FOT. i thought it might be detonation but i'm not sure

I don't know how to diagnos that it is a cavitating pump. All I know is that when I go WOT power is good it just starts to rattle around 4000 rpms.

 

[blueflamed03]

Bruce, what are you using to clean the MAF, and are you cleaning the TB as well?

 

[YUOnDaGround]

I use CRC maf cleaner for the maf and I use Generic Throttle body cleaner for the TB.

 

[afpj]

If MAF and TB cleaning don't work, consider the O2 sensor(s)...may be slightly loose. THere are other posts of rattling noises caused by this, but don't recall if at specific rpm.

 

[brad6603]

Im had to replace both of my O2 sensors from the mystery rattle sound. When i removed the factory O2's i could shake them and they sounded like the ceramic inside was busted. Replaced them with new ones and the mystery rattle sound was gone.

 

[blueflamed03]

good info Brad!

 

[andrew383]

It could be the either belt tensioner also...

Is it worse with the ac on or off??


Also are you hearing this in park or driving??

 

[Husker1111]

ya i posted something but im def wrong nvr mind ignore me idk how to delete a commment

 

[YUOnDaGround]

It could be the either belt tensioner also...

Is it worse with the ac on or off??


Also are you hearing this in park or driving??

Only while driving while at wot at high rpms and I haven't noticed a difference related to ac being off or on.

 

[ScottL4619]

Mine does this too. My 2001 also did the same thing. It only happens when you really stomp on it. I read somewhere that it was normal for these engines and it's really barely noticeable.

That said, it may not be normal if others aren't hearing the same thing. I clean my MAF and throttle body about every 2nd oil change, so I don't think they are the issue. How hard is it to change O2 sensors?

 

[YUOnDaGround]

Mine does this too. My 2001 also did the same thing. It only happens when you really stomp on it. I read somewhere that it was normal for these engines and it's really barely noticeable.

That said, it may not be normal if others aren't hearing the same thing. I clean my MAF and throttle body about every 2nd oil change, so I don't think they are the issue. How hard is it to change O2 sensors?

I may end up changing out the o2 sensors just to see what happens.

 

[brad6603]

Before you go out and buy new ones. Take a wrench and unscrew your old O2 sensor and shake it to see if it rattles. If it does thats the problem.

 

[YUOnDaGround]

Before you go out and buy new ones. Take a wrench and unscrew your old O2 sensor and shake it to see if it rattles. If it does thats the problem.

Good point.