Jmai22

i was told that this is because of the metal expanding and changing shape. and it was from the cat. i was wondering if anyone else has this problem or is it just me. is there anything i can do to fix it. its kinda embarrasing when i park in my friends garage and you hear this ticking noise.

also when i pop the hood the engine seems much more hotter than other car hood that i have opened. is a gs a hot running car?

link13

All of the first gen GS3s that I've ever been around make this noise and so do the SC3s along with assorted other Lexus vehicles. It's either the cats or the heat shields near the cats and I would have to say I doubt there's a fix. It doesn't bother me too much that mine does it.

blue wax

all metals cooling down, make that noise, this has nothing to do with lexus whatsoever............

yezzzzzzzzz

geees300

dude
i have the same irritating noise that i live with but not all the time. start supplying ear plugs instead...lol

Sovero1

I have the same noise. From what I was told this is pretty normal, esp. as the exaust system is getting older.

I am not sure if this is true or not, but if cat converters really do contain coal, it could be that very hot coal is bouncing around the cat while settling/cooling down.

If the above theory is correct, the only way to eliminatethe noise is to replace the cat with a new one.

Ed

mooretorque

they don't......they do have platinum, rhodium and some other rae metals on which the various pollutants are adsorbed for speedy chemical reactions (note: catalysts do not change the endpoints of a given reaction, just the speed at which it proceeds to completion, chemically speaking)

jmai, all metals expand when heated and contract as they cool..differential rates of cooling by both different parts of a metal surface and by the differing rates of heat loss by dissimilar metals lead to those ticking sounds...........cadillac even utilizes that in one of the catera commercials, where as the car speeds up, begins to turn orange from air friction, then stops at a stop sign, the color fades as the car "cools" and you hear the characteristic ticking.......what a wad of crud........

the point is, this is normal, and it occured the first day you drove the car, and will every time you drive it.........just basic physics