rattle noise when on the throttle

pektel

pektel

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Hey guys. Recently I've noticed that when I really get on the throttle, I will hear a metallic rattle noise that sounds like it's coming from the front of the car/engine bay area. It only happens when I first hit the throttle, and only is there for a second, then gone.

Any ideas what this could be?

I also have what I believe is an exhaust leak causing a tick sound from the driver side. I think it's exhaust leak because the pattern of ticking is in direct proportion to the rpm's.

Any help/ideas would be appreciated.

Thanks!
 
could be a cat bang on them with youre fist or bang on the exhaust farther down youll be able to tell if the catalyst material has started to break up.
 
you know, clogged cat could be a culprit. I've noticed what sounded like a muffled backfire and bog down before it kicked in.
 
NYC LS8 said:
Tune? Could be too much timing.
Click to expand...

#1 to this. I was getting some noises. Didn't so much sound like pinging so I didn't think the tune was an issue. After time spent trying to figure it out I ended up reducing the spark on my 0-2000rpm setting on the tune, down two clicks, and the noise seems to have gone away. It was a similar sound to what you're explaining.
 
Simple answer

Low Octane gas, water in gas, cheapest test would be to fill up high octane and get dry gas to add to the mixture. :)
 
Maybe, but it doesn't sound like pinging. I only use 91 (in fact, used non ethanol 91 last time), and have bought from a few different stations recently.

Never heard of dry gas. You talking about octane booster?
 
pektel said:
Maybe, but it doesn't sound like pinging. I only use 91 (in fact, used non ethanol 91 last time), and have bought from a few different stations recently.

Never heard of dry gas. You talking about octane booster?
Click to expand...

I had a ticking sound for a while when I got on the gas. It sound like something was flapping around in the engine. When I upgraded to 93 Octane gas I havent heard it since. And I know that is the culprit because I took a trip up north and used 87 octane to save a little money and it did it the whole way when I hit the throttle. I guess there is no knock sensor in our cars?

Theres also a rattle that comes from the exhaust it sounds like, maybe the cats. Its only at full throttle.

I also get a wine too at full throttle too. It sounds like its super charged or something.
 
knock a couple of degee's of timing out of it, as was suggested.

IF it "IS" ping and you dont get a handle on it, it's gonna break/melt something.

how hard could it be to "knock out" a couple of degree's and retest?
seriously... RULE it out, rather than just say "it doesn't sound like".

it's very difficult to "diagnose sounds" over the internet.

if I'm not mistaken this has been suggested to you before in another thread.
 
Yep, you're mistaken.

first thread I've posted about this issue. The other issue you are referring to is the tick sound that happens at idle too. This particular issue in this thread is only heard when I get on the gas in SST. I kind of thread jacked the previous thread you are referring to, and the OP of THAT thread was given the suggestion to pull timing.

Nonetheless, I will step it down a couple degrees. I've never messed with the end user options on the xcal2. is it something as simple as "down 2 clicks" when I get to a universal timing section? Or does it go by RPM level?
 
bad thing, is a "Tick at idle" and a "rattle under load" sounds like "needle and the damage is done".


The Xcal end user adjustments are fairly easy.
You might have a "global timing" adjustment that makes it easy.
you could pull 2-3 degree's out of "everywhere" with the global adjustment
(this is just like twisting a distributor)

Also there are some "finer" adjustments that allow you to adjust from
0-2000 RPM's
2000-4000RPM's
4000-8000RPM's

If you have the global adjuster, just take out 2-3...
Then if it doesnt "rattle", you can go back and see "which" RPM range you can "add spark" back into...
Global, will give you a better "test"
 
I think my car recently started doing this. I turned my tune down a couple clicks but I'm still hearing it.

Since I bought the car I've suspected there's a bad pully or tensioner or something on the belts. It sometimes ticks/rattles when cold, goes away very soon after I put it in gear. Belt also squeeled for a few days after I got it.

Could this noise be a bad pully rattling around? It sounds like maybe it could be to me.

The fishy thing about this is that it doesn't always rattle, not even under load. It's when I suddenly jump on it and floor it that I'll hear it. Haven't heard it yet when just accelerating medium-ish to get on a freeway, or jumping on it from a stoplight.

Other than this noise my car runs great. No misfires so far, it's got all it's power and there hasn't been any hesitation.
 
pektel said:
Hey guys. Recently I've noticed that when I really get on the throttle, I will hear a metallic rattle noise that sounds like it's coming from the front of the car/engine bay area. It only happens when I first hit the throttle, and only is there for a second, then gone.

Any ideas what this could be?

I also have what I believe is an exhaust leak causing a tick sound from the driver side. I think it's exhaust leak because the pattern of ticking is in direct proportion to the rpm's.

Any help/ideas would be appreciated.

Thanks!
Click to expand...

I get the exact same noise when on the throttle...someone on LVC said it may be the torque converter:( :( as I understand it ...you have to do almost the same thing to replace the torque converter as you do to install a new tranny...and as I further understand it...if you get the torque converter replaced it will only "hold you over" for a few months/thousand miles until you have to replace the tranny completely...only thing is it (torque converter) is about $1,300.00 less:eek: :eek: :eek:
 
Hmmm... time for a higher stall then.

TC makes a little sense because it only happens while in Drive. I hope it's not though. That may be a LONG day to replace.
 
i don't think the noise he's describing is the transmission. it sounds like either too much spark timing or bad cats as stated above. i have the same symptoms under full throttle only. the media is probably starting to come apart. i have jumped under the car after being on the highway for an hour and nothing is glowing red so its not blocked, but this might be something you can check too. i reduced my timing back to stock and the sound was dramatically less noticable, but it was still there to some extent. cats are cheaper than transmission converters. i'm going to probably start there. i'm also doing coils and plugs to fix a misfire, which may or may not help this noise issue (the noise does not occur during the misfire as it only seems to miss at idle, and with light throttle in 5th).
 
Well, the TCI streetfighter converter runs about 500-550. Is that more expensive than cats?

But I will check out the cats. I should also tune back to stock to see if that changes anything. I pulled out 2 degrees from each rpm range, and the sound is still there.
 
1bad4.6l said:
could be a cat bang on them with youre fist or bang on the exhaust farther down youll be able to tell if the catalyst material has started to break up.
Click to expand...

I literally thought you mean a feline at first... I'm an idiot.
 
Hmm... if that's the issue, they will just be removed. No inspections in MN, so I'm good to go. I'll have to go out underneath and take a look once it stops raining :mad:

That sucks about getting pulled over for tint. What % was on there again? I don't remember it being dark enough to be pulled over for. I know it was darker than mine though.
 
pektel said:
Hmm... if that's the issue, they will just be removed. No inspections in MN, so I'm good to go. I'll have to go out underneath and take a look once it stops raining :mad:

That sucks about getting pulled over for tint. What % was on there again? I don't remember it being dark enough to be pulled over for. I know it was darker than mine though.
Click to expand...

When I had the tint done 3 years ago it was for 35%. The cop tested my window and said it was 32%. He also gave me a warning for my license plate frame. The car will stay as is. There will be no removing of tint or frame.:D
 
Thanks for the info. Is the water pump on the drivers side?
 
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