1998 Gs 400 Engine Noise

[rfcbuf]

My 1998 Gs 400 with 60K miles has for the 2nd time in 2 years made a loud engine knocking or valve knocking noise when cold strarting the engine. First time it happened Lexus dealer said it was a piece of carbon stuck in valve and that is why the noise disappeared soon after driving. Same thing happened today. Noise at start-up followed by quiet engine after short warm-up. Is this a common occurance for a car like mine used mostly for short trips? Has the engine been harmed if the noise only occured so infrequently?

[TurboGS300]

Are you using premium fuel? I doubt any damage has been done. Short trips are one of the worst things for a car. As the engine never gets hot enough to burn all the carbon and other deposits off. I recommend you take you car on a vacation or do more frequent maintenance :D Are you using synthetic oil? Maybe you should start.

[deadmilenko]

Synthetic oil is difinitely they way to go if you plan on having your car around for awhile. It will pay off in the long run. I run full synthetic oil in every vehicle that I own. Full synthetic oil, brake fluid, pwr steering fluid, trany fluid ect.........

How cold was it outside when you started your car up? Did you let it warn up before you drove it? Letting your fluids in your Lexus warm up for 5 minutes or so is great for your engine before you drive it especially in the winter, if you have the time to do it. If not you should get ready 5 minutes earlier your car will love you for it. Or get a remote starter, so you can start it from the convenience of your home with out even going outside in the cold.

[VGR]

Are you using a Toyota oil filter?. Has the engine oil been changed at least every 6 months regardless of mileage? If your answer is Yes to both questions then the noise may not actually be coming from inside the engine, but from some reciprocating accessory or part attached to the engine.