I recently purchased a 2005 GTO with 191k miles. Do I need to change the timing chain at 200k or is it designed to last longer. The owner changed the water pump but didn't change the timing chain while they were in there.
I tried looking at forums and they said it went for the life of the motor or when you rebuild it. Just needing some verification on it.
Still a long way to go to change the TC when doing a water pump. Agree with the first reply. If you're going to pull the front cover, change the cam and oil pump too.
IMHO at that mileage, if it ain't broke, don't fix it, and don't mod it either. I would just run it stock. However, if you must modify it:
i would think about your goals with the engine, and how it's been treated for the past 191k miles. if you don't know, assume the worst with a GTO. with a high mileage LS, if you're going to tear into it and mod it, i would check more than the timing chain. cam bearings should be examined. lifters and trays should be definitely be replaced if your putting in a new cam.
If the engine was taken care of, it should still be a good basis for modification. there seem to be plenty of examples of people with higher mileage LS engines that have had success with tearing it open to swap a cam, and a few that haven't.
I'm a guy who likes to replace rather than inspect. If you intend to DD this car, just drive it as is and put a sheet of cardboard under it when you park if leaks start.
If it were me and I intended to make this car fast, I'd buy/build a short/long block. Then, I'd sell everything I took out to recoup some money.
However, I am me, and I bought an '05 earlier this year with 160K on the clock. When cold, I heard lifter noise. So I took it down to a short block to replace lifters with new LS7 (OEM). While I was in there, I did the timing chain, oil pump, front seal, etc. I'm a firm believer in the "while you're in there"...
So in conclusion, I'd just run it as is. Think about this: if you hop timing and smack a piston, you'll be wanting a new motor anyway because, well, it has 190K miles anyway. Would you really be upset about ruining a "perfectly good" 190K mile shortblock? Or would you be grateful for a legitimate reason to replace your 190K mile motor?