Lexus IS Forum banner

1 - 12 of 12 Posts

·
Registered
Joined
·
20,481 Posts
Discussion Starter #1
When the RPM falls back down to around 2500 after revving it up, the engine makes a metallic noise like something's dragging. Anyone know what the problem could be??? Thanks.
 

·
Registered
Joined
·
260 Posts
the car have some engine noise(metalli sound) when accelerate.. i have tried so hard to pinpoint what caused it, so far i couldn't and this is bothering me..
 

·
Registered
Joined
·
12,157 Posts
how about a sound clip, it is very hard to imagine what you are describing and where it is coming from.

------------------
"the gene pool could
use some chlorine!"
http://www.shitonhonda.com"-Funny Site!
 

·
Registered
Joined
·
20,481 Posts
Discussion Starter #4
I don't know what noise IS300#1's makes but mine sounds like the noise you get when you put a piece of paper in a fan. Hard to explain but it makes the noise when I let go of the accelerator. I'm taking it to my dealer friday- let those goofy bastards look at it.
 

·
Registered
Joined
·
260 Posts
i have tried to hear/find that noise when the car parked, opened hood, step on gas... can't find anything, sound normal, only heard that when under acceleration on the road, sounds like metal rip against metal sound, but not so loud. i can't even know how to tell the dealer about this when the 5,000miles service comes.. besides this, there is a rattle noise from the front passenger side everytime on the rough road at this cold weather(radio off).
do anyone have this rattle noise from the passenger side on rough road? or just the weather problem?
 

·
Registered
Joined
·
20,481 Posts
Discussion Starter #6
I brought my car to the dealer and they are saying that the catalytic converter has corroded inside and has started to clog up. Anyone know how and why this happens?? I've had my car for only two months. The gave me an ES for a loaner. Is it me or is this car alot smoother than the IS. Alot slower though and FWD- handles like [email protected]#. Now I know how it feels to drive an Acura.
 

·
Registered
Joined
·
257 Posts
i believe the converter might have corroded from buildup of carbon and other exhaust by-products. If i'm not mistaken, the exhaust manifold is extremeley convoluted...all kinks and turns. i think lexus/toyota did this to reduce the power output although it kills the gas millage too.

Enough already with people ragging on FWD. Seriously, can you REALLY feel the difference in normal driving? Have you really taken a RWD car vs. a FWD car out on the track? You jump in and push a FWD car much harder without fear of "lossing it" than a RWD car from the start. Especially in the rain. (look at the type-r's kicking butt) The RWD car will be faster...buts that's ONLY if you've mastered the limit of adhesion for traction. IE you can drive at the limit and not spin out like a damn fool.

(i have a RWD RX7...i'm not just spouting off)
 

·
Registered
Joined
·
77 Posts
Originally posted by PMD911:
When the RPM falls back down to around 2500 after revving it up, the engine makes a metallic noise like something's dragging. Anyone know what the problem could be??? Thanks.
From your description, it sounds to me like the valve train. I once owned a Mazda that made a sound like you're describing after revving.

Is it louder with the engine cold than fully warmed up?



------------------
99 M3
01 CL Type-S
 

·
Registered
Joined
·
20,481 Posts
Discussion Starter #9
Why would by-products buildup in only two months (length of time I owned my car)?? Could anything else be effected by this? Thanks.

Originally posted by RotaryBzzz:
i believe the converter might have corroded from buildup of carbon and other exhaust by-products. If i'm not mistaken, the exhaust manifold is extremeley convoluted...all kinks and turns. i think lexus/toyota did this to reduce the power output although it kills the gas millage too.

Enough already with people ragging on FWD. Seriously, can you REALLY feel the difference in normal driving? Have you really taken a RWD car vs. a FWD car out on the track? You jump in and push a FWD car much harder without fear of "lossing it" than a RWD car from the start. Especially in the rain. (look at the type-r's kicking butt) The RWD car will be faster...buts that's ONLY if you've mastered the limit of adhesion for traction. IE you can drive at the limit and not spin out like a damn fool.

(i have a RWD RX7...i'm not just spouting off)
 

·
Registered
Joined
·
257 Posts
it could be in the construction process of the converter "brick". A catalyst works by having a great surface area upon which unspent hydrocarbons (HC), nitric oxides (NO) and carbon monoxide settle. The converter lowers the activation energy for change of a CO and HC into something less *reactive* (and polluting) like CO2 and H20. I believe that right now, we are seeing the first generation of ceramic-based catalytic converters w/ imbedded metals. Reading a recent article in grassroots motorsports, their "project miata" had a converter failure with a new, hi-performance, hi-flow converter. As failure can occur in ANY product whether it be OEM Lexus or OEM Acura(cough-cough
), something like a converter failure can occur in a low-milage canister, especially if the converter is never warmed-up properly to operating temperatures (ie lots of start-go-stop shut-down) and allow the conversion process to occur. Bascially you have a improper buildup of reactive substances in the converter that will destroy the "catalyst" within the canister. I.e. possibly poorly designed converter goes bad faster...breaks down internally and viola! rattles in the converter and *stinky* exhuast. Just my idea....
 

·
Registered
Joined
·
257 Posts
Oh yah, one more thing that might make this idea float. I remember seeing a post from someone who took the air-to-gas ratio in the exhuast. I think it was in the performance section from a Toyomoto dyno run. It showed the IS300 running rather "rich" (an unusual amount of unburned gas-HC- in the exhaust) which is kinda not good. Eck! Lexus should've just smoothed out the damn exhaust manifold and made more power! What's the use of having unburned gas in the exhuast?!? Hope you are reading this Lexus USA!!!
 
1 - 12 of 12 Posts
Top