Jaricho

I have a 01' GS300 and over all it's been a very good, car no major problems. Recently I noticed that whenever the needle is just under 2k rpms (I think between 1850 rpms and 2k rpms) I can hear rattling sound, but it's only when I'm accelerating. It's most noticeable after a cold start. Does any one else have this problem? Or know what it is? Any help would be greatly appreciated.

twool

I have the same problem. A low RPM makes something rattle. If anyone has a suggestion on how to fix, please let me know!

Freshtoe

my car has the rattling sound too!

I was wondering if the butterfly on the intake manifold was getting loose.

I hope someone figures this out.

very odd...

runyun

iTrader: (11)

Hey guys,
I'm new to this forum...

There could be a lot of things - but sounds like an exhaust shield to me.
That's common with a lot of cars, just go in and tighten all the bolts on the exhaust shield.

Freshtoe

You might be right about that. It sounds like tinny metal rattling around.

I have a feeling that as soon as the metal reaches a higher heat, it ceases to ratlle. I've seen this kind of thing before in other instances... I'll try and tighten things, but it does make you wonder... If I find that its and exhaust shield, I was also thinking that I would try to put a crease in it to help give it some more ridgity, perhaps rattling less?

Anyone else have any ideas?

Jaricho

It might be the exhaust shield but for me the rattling noise only happens when the needle is just under 2k rpms and only when I'm accelerating. Once the needle falls below (if I take my foot off the gas) or rises above (as I continue to push the gas) the rattling stops.

lexusgs4

this morning I noticed the same thing, but it only happens when the engine is cold. After it started warming up no more ratteling. I was wondering if maybe it was something loose under the dash or a motor or tranny mount loose or going bad.

joshoowa

iTrader: (1)

is it coming from the front of ur car or rear.... i had noise from the rear and it was a loose heatshield.... but now i ahve a low rattle noise in the front of my car sounds like its coming from within the dashboard.

Freshtoe

mine feels like its up front...

I kept thinking something was 'dangling' in the air intake...

that's how close that sound was...

still is that way too.

Jaricho

Mine sounds like it's coming from the front of the car. It seems like I'm hearing it through the air vents. If it is a loose heat shield then why is it that it's only happening in a specific range of rpms?

Navaz

If you recently had your car serviced, and if they changed the coolent there may be air bubbles. have that checked out, it should solve the problem.

wheelz00

hey i have a gs 400 and it does the thing i am a mechanic and i think it's the nox sensors there susposed 2 read what type of gas u use most of the time it means cheap gas but i use 93 and it still does it i put 94 in and it stopped a friend of mine has a 400 but he doent drive fast at all and his doesnt make that sound so just try and upgrade ur gas it might work

runyun

iTrader: (11)

It happens because at certain rpm ranges - you car vibrates differently.
Trust me, its as simple as lifting your hood and tightening all your exhaust shield bolts. Usually 10mm bolts (for japanese cars) If its coming from under the body - ck the cat-shield... its a common thing and unless I can listen to it myself, I'd bet on that.




Coolant? Why would coolant cause rattling? Bubbles in your coolant would cause your car to overheat (if you had a lot of bubbles) If you're replying to the guy that said it sounded like it was coming from the air vents, then, I have no clue. But, you shouldn't be able to hear bubbles in your coolant nor should it rattle.




lol, this is the funniest. You're a mechanic? Then you should know there's no such thing as a NOX sensor? lol. NOX is a type of gas released from your exhaust. Check your inspection papers - you'll see NOX listed there. =)
What you're describing sounds like a KNOCK sensor. And they don't "read" what type of gas you use. They feel for unusual vibrations due to misfire,knock,etc. (thus the name, "knock sensor") Those can be caused by low octane - but again, doesn't relate to "rattling" noise.

Navaz

The reson I said to check for bubbles in the coolent is almost everytime I get my coolent changed I get that same sound i first noticed it 5 years ago and since then the fix to the problem was to bleed the lines properly.

jtanoyo1

Hey bro, he might actually have something here....forgive his spellings but he really could be onto something. Bad gas will cause engine knock, long abuse through bad gas will cause the engine knock so severe that you could be standing a few feet away when the car is accelerating and you could hear the strange kkkkkrrrrrrrrrrrr sound like as if some bolts were coming loose and something under the engine falls apart. While they don't exactly "read" what gas you use, they do "read" misfires and bad combustion. The sensor will retard timing accordingly, and usually when it can't retard the timing anymore, the engine will detonate or knock.

Please don't be quick to dismiss his opinion. These guys' "rattling" issue could seriously be engine knocks, especially if it was coming from the front.