runyun

iTrader: (11)

Ya, after I posted, I realized my response may have came across harsh.
But you have to admit - how can you claim to be a mechanic and say you have a NOX sensor?
Sorry, couldn't resist

wheelz00

It's cool just in a rush any way try nos octane booster it should work

amwendwa

I posted about this about 2 years ago. I've brought it up with my service advisors numerous times and we could never pin point the problem. Actually I'm going in next Friday to try and isolate the cause and will ask them to tighten the exhaust shield. I will let you guys know of the outcome.

redjeeper

I had this same rattle that sounded like it was coming from several different places in the engine bay. It almost sounded like a paper bag was stuck in the fans. It turned out to be a cracked flexplate on the transmission and cost me $700 to fix. I will post a pic of the broken part later tonight when I get home.

smelkony

I had the exuast heat shield removed on my sc300 thinging they were rattling, but the same noise is still there when i slightly accelerate. I hear it more with the a/c off, stereo off, and windows closed.

tonylani

Can you post a pic? Why was it not covered under warranty? I've got a similar rattling noise when I accelerate.

antbo

iTrader: (1)

i needed to bump this post up cause im also havin this problem. i just bought a 99 gs300 and it has the same problem. its seems no one posted after, or if anyone fixed the problem. help please. its driving me nuts!! same with that noise you can here from inside the car at low rpm's. sounds like water or somethin. that craps annoyin to.

spyder357

Has anyone found a solution to this problem? I too have the same problem, when the needle is just under 2k rpm's and I accelerate it rattles.

Please email with any solution you might have.

Freshtoe

I had Steve at LMS check out the sound, and he said that he thought it might be coming from the catalytic converter area... So I think I'm going to have to take it to lexus in a week or so. First I have to take off my heat shield and cold air intake. Lexus would blame the problems on the performance parts, I'm sure.

Anyhow, so Steve was saying that if it is part of the 'Emissions' system, there is a warranty on that under 100,000 miles.

I'll let you guys know more as this happens.

Also, this seems rather common in the 99 year of the GS so far... how odd...

antbo

iTrader: (1)

let us know ASAP! im a little near to 100k

Freshtoe

I went into lexus and they said that the noise was coming from my catalytic converter. I am currently in the process of getting lexus to cover this as an appeal to the warranty. I believe that as long as you are under warranty, you might be able to get this fixed due to the 'emissions' warranty.

Anyhow, they have diagnosed this, and it seems to be the problem.

As for exhaust shields, any qualified tech should be able to fix that. I watched them do it, and they even tightened a shield for me. Either way, this rattling is much louder than any shield could cause.

I'm still waiting on the outcome, but in the meantime, its worth the trip to the dealership to find out if they can fix your problem.

I'll post more when I get more info...

Grush

I had a similar rattle in my '01 GS300. I think it's important to distinguish between a hearing metallic rattle and pinging. The pinging has always been a problem, and Lexus advised that it's the gas, especially in CA. An octane booster could hellp in this case. However, the sound like a metallic rattle/vibration turned out to be a broken heat shield that attaches under the Mass Air Flow assembly (between the air filter box and the throttle body ). It's a thin, tin shield that broke off at it's connection point. I strapped it back securely with a plastic zip tie. Rattle fixed.

I still have pinging upon acceleration. I occassionally hear a sound like fluid with bubbles behind the dash (like air bubbles whirring past the heater core). However, the rattling metallic vibration from the front was fixed. Hope this helps. Now to try some octane booster!

redgs400

I've noticed this rattle primarily when I'm leaving work, and as previously noted, only for the first block or so. It seems to be coming from the direction of the dashboard.

I have had a previous problem with bubbles in my coolant. I can best describe the noise as sounding like a bunch of loose BB's in my transmission--hence why my original complaint to my Lexus dealership that I suspected a tranny problem. A road test with a tech' and he concluded that it was likely bubbles in the coolant. BTW it took them several HOURS to properly bleed the cooling system to fix that problem.

But... this rattle is NOT bubbles in the cooling system--at least it's not the same sound.

Freshtoe

I just got my car back, and it sounds perfect.

Lexus gave me the parts in ''Goodwill' , so instead of a 1400 dollar bill, I only paid for labor, roughly 336 dollars.

Hopefully some of you have cars that are still under the Emissions warranty, but mine was not, and they still fixed it.

Thanks Lexus of Westminster for fixing my car!

(Now that the 'loud annoying rattling sound' has been solved, it time to get a muffler system!)

blindsk8er

So what was it that they fixed?