Timing Belt Sleuth

[awilliams]

Hello All,

I just purchased a Lexus from an independent dealer this past weekend. The car has been well taken car of both inside and out. Here are the details...

* 2004 Lexus GS 300

* 129,423 miles

Looking at the service records from the Lexus dealership (in Riverside, CA), it doesn't look like the timing belt has been replaced yet. The last record of service ended on 11/23/2010 (at 95,164 miles). Looking at the CarFax, it passed emissions test at 113,256 miles and later was put up for sale by the same Lexus dealership at 128,798 miles.

I called the Lexus support number and asked if they would contact the previous owner on my behalf to see if the timing belt had in fact been replaced and by which repair shop, but that was a dead end.

I removed the top timing belt cover to take a peak at the belt to see if there was any major signs of wear and if there was still wording on the flat part of the belt. I know this is not a good way to determine if the belt has been replaced or not. Just thought I would check. One thing that I noticed is that someone painted the "O" marks on both cam pullys/sprockets white that indicates TDC. Also the flat side of the timing belt texture is really dull and sort of abrasive to the touch and the manufacturer and part# labeling on the timing belt looks really good. No signs of fading.

Which leads to my question........

I'm wondering if the marks were painted when the engine was first built before factory installation or if it was done by a mechanic (if the timing belt was replaced)? Could these painted markings indicate that the timing belt was actually replaced? Is it standard procedure for the factory to paint the TDC marks on the cam pullys?

I'm a bit reluctant to drive the car alot until I get the timing belt replaced so I thought I would do some research regarding the markings but haven't found anything definitive. I was hoping one of you die-hard Lexus enthusiasts could shed some light on this. ;)

Thanks

[2JayZ]

Not sure about the timing paint marks being factory applied but I'm sure someone here does and will chime in soon.

In the meantime you may wish to take a look at the condition of the water pump. No good mechanic, shop, or Lexus Service Department does a timing belt service without replacing the water pump. So if it looks new, or newer, that could be a sign the belt was replaced.

[bonesnj]

Hi All First time Lexus GS400 owner! first time posting too,

I Bought my Lex with 200K owner said she changed belt I checked, The belt it looked new with Gates writing on it, teeth also look mint I also checked Water Pump it looks diferent "newer" then rest of metal sorounding it.

Belt was nice and tight.