I just purchased a 99 LS400 w/ 144k miles for my son. It has a non-Lexus sticker on the engine stating timing belt was changed Dec 2011 at 103k miles. That lines up perfectly with with consistent Lexus oil change service records for both time and mileage. My assumption is that it was taken to an Indie for timing belt change.
- trust but verify! ;-) I know there isn't an exact science by just looking at a timing belt, but we were cleaning the MAF sensor and throttle body anyways, so we pulled the passenger cam cover. My impression is that the belt is in pretty good shape. No cracks, no missing teeth. The belt tension seemed good and the belt felt smooth and supple. Also, no oil or contaminants!
-I've spent my last 750k miles maintaining BMWs, so not much timing belt experience. Does this seem like a 40k timing belt vs 144k? Also, I didn't see any timing markings that seem to be present on a factory belt, maybe aftermarket?

All advice welcome!
Brian

 

Looks ok from the top but how is the nubbed area?

Only 41k miles on the belt but if there's doubt,change it.Especially if you can do it yourself.

 

Unless there are big cracks, or teeth and chunks missing, I wouldn't worry about it. The factory marks ALWAYS seem to wear off pretty quickly from all the belts i have done over the years, and your looks like its still brand spanking new from the pictures... in my opinion.

 

Looks real nice.

 

Thanks Gents!
All of the teeth are there and don't even look that rounded. In the picture, they 'mesh' with the cam gear almost perfectly with no space that might show wear.
Well, I feel better about that! Now, we have to tackle leaking valve cover gaskets and cracked power steering hoses! ;-)

 

Looks good.look for hevy wear marks and cracks!

 

it looks good, no need to change it!
If am in your place i will not change it, after all this is all up to you!

 

that's a textbook picture of a healthy belt!

 

Ok we all know that it basically looks new.