Vitaly78

Hi, I just bought a 2001 Lexus RX 300 AWD and there is constant knocking/ticking type of the noise that just wont go away. Plus, the car has rough idle at stops. Is it really fuel injector problem or engine??? Can anyone help out with this issue since the Lexus service people say its a normar noise and wont do anything about it. Thanks!!

HarrierAWD

Might be clogged-up fuel injectors. Use a bottle of fuel injector cleaner. If things don't improve, take it to another Lexus dealer.

Lil4X

ANYTIME a dealer makes a statement like that, turn around and RUN! See another Lexus dealer for a second opinion. "They all do that." ranks right up there with "The check's in the mail." on my chart of most common lies.

That ticking sound probably indicates a stuck injector, and is not normal. Usually the noise is accompanied by a rough idle and/or a misfire under acceleration. Most of the time a good commercial injector cleaner will clear the problem. Techron by Chevron is one (it's also an additive to their fuel blend). Don't be tempted to "overdose" by adding more than the recommended amount of cleaner to your tank - it can destroy the rubber components of the fuel system.

A better treatment can be done at your local shop, directing a concentrated cleaner directly into the injectors as the engine is running. A third method of cleaning - expensive, but the best - is having a shop (with the proper equipment) remove the injectors and "backflush" them with a cleaning compound to wash particles of rust, rubber and gunk out of each injector.

Here's a good discussion on cleaning injectors: http://www.babcox.com/editorial/ic/ic30336.htm

Good luck!

Vitaly78

Thanks for feedback!

LexusSexus

Hopefully this doesnt apply but my 99 Lexus was running rough, idling rough and even stalling on me. I thought for sure it was an injector but the oil light came on as well. Turned out to be a "sludged" engine that required an engine replacment under warranty.