spence288

iTrader: (1)

My 02 generates a rattling noise around 3000 rpm. It is definitely coming from the engine. In some ways if sounds like a ping caused by low octane but that is not the problem. Maybe similar to unadjusted valves for those of you that remember adjusting them.

I have taken it to the dealer and they told me that it is normal. They said it was injector noise and they checked 3 other cars and mine was in the middle as far as how loud it was. It is loudest when it is cold. It much quiter after driving about 1/2 hour.

Anyone have any ideas...it bothers me since to sounds like something is ratting around in there.
Thanks

Pearlpower

iTrader: (2)

Hmmm, rattling and pinging are two different things. But if the dealer says it is injector noise, well these V8's can have loud injector noise. But....First thing I would do is change oil to something else. What are you running currently?

Also some injector cleaner such as Techron is xlnt. Runs about $11.00 for a 20oz bottle from Kragen Auto since your in California. Not the fuel system cleaner, but the Techron Injector cleaner.
Lee

spence288

iTrader: (1)

Thanks for the ideas...
Doubt its the oil since it gets quieter with heat. running 5-30 now

have tossed in the injector cleaner...no help there.

Pearlpower

iTrader: (2)

spence288,

Well a few things get quieter when the car gets hotter.
One would be the valves but since these cars do not have hydraulic tappets, that is out.
Other is a leak such as an exhaust leak. Those will always start out loud and get quieter once warmed up as the metal expands. That said ,all 3 of my V8 Lexus's and V8 Tundra make a tapping sound of some sort and I have never been able to trace it to any abnormality in the engine.
Lee

spence288

iTrader: (1)

Thanks for the thoughts. Exhaust leak crossed my mind too.
It just isn't quite the right sound. It's more like something is just lose and rattling around in there. Very strange. One other intersting point oi sthat it does not make the noise unless you are driving. Reving the engine to 3000 rmps and holding it there produces no noise. Can't image there is something in the tranny. Any ideas?
thx

JCtx

You know, maybe they're not the same noises, but all 4 of my V8 Lexii (SC400, LS400, GS400 and now SC430) have a very annoying engine noise but when HOT. This thing is most noticeable if you park on the left side of your garage, as the sound bounces against the wall. You can also hear it if you're next to the engine. Sounds like a rattling sound, and it starts doing it when fully warmed up. I'm sure it must be an accessory, like the A/C, power steering, or alternator. Definitely not Lexus like.
You didn't mention how many miles on your car, but these engines require valve adjustment at 60K miles. Now all manufacturers claim their cars go 100K miles without a 'tune up', but if you read the fine print on valve adjustments in Honda/Acuras and Toyota/Lexii, they say 'unless noisy'. Hondas are a piece of cake, since they're SOHC, with threaded adjusters, but I think Lexus has shim under buckets, like motorcycles, which require cam removal if out of spec. And once in there, you might as well change the stupid belts too (why the heck not use chains and hydraulic tappets like BMW and everybody else? Jeez).