I have a 1997 LS400 Coach with 78000 miles. The owners manual syas to change the timing belt at 90K. Since this service is rather expensive ($1500 from local Lexus dealer), and since no damage will occur to the engine should the belt break, what is the problem in just leaving the original belt in until it eventually breaks? Seems the old addage "If it ain't broke, don't fix it".
If you can e-mail me with your comments I would appreciate it.
Thanks, CaptBud
CaptBud330@yahoo.com

 

i know they say that in the event of the timing belt breaking there won't be any damage, but i've seen non interference motors that have sustained damge because the belt broke while they were on the doing highway speeds and because the engine was turning at a greater rpm the valves touched the pistons. i haven't seen it with our engines but i still would'nt take a chance if i could help it. plus if the belt breaks you'll be stranded until the flatbed comes. btw i have seen those belts last up to 135k!

 

Actually, the 1UZ-FE from 1990-1994 is a NON-intereference engine. From 95 on it is an INTERFERENCE engine. Interference means that if the camshafts are not turning and the crankshaft is (IE: broken timing belt/chain) the valves WILL HIT THE PISTONS. The damage if this happens is very bad and can run from very slightly bent valves (new valves and valve job X 32) to the engine being completely destroyed. A buddy of mine had a tensioner fail on his 90 Infiniti Q45... pistons hit valves, connecting rod broke, punched hole through engine :eek:

On a 95 and newer, do the work. On the earlier engines, a belt failure doesn't ruin the engine but does mean a tow truck ride (not always a damage free event!) not to mention the possibility of a very inopportune time of failure (crossing a busy intersection, in the wrong part of town, on way to big meeting, on way to pick up HOT date)

 

I would agree with JBrady. He knows LS very well. I had my changed at 130k. I changed along with powersteering, water pump and few other things.