I recently purchased a 2004 LS430 with 50,000. Great, great car after owning 5 BMW's. I have replaced all fluids with the exception of the transmission. The manual says replace the timing belt after 108 months.

Thoughts?

 

The 3UZ-FE engine is an "interference engine" much like, for example, the engine in a Ferrari 328 or similar. If the camshafts (there are a total of 4 - double-overhead each bank of cylinders) are not timed with the stroke of the pistons, the valves will be struck by the pistons destroying the engine. This could / would occur if the timing belt snapped while the engine was running. On the one hand, that is the risk. On the other, you can read CL members' actual experiences, change intervals & opinions on this topic on existing threads. Personally, I don't subscribe to the 9-year old change interval for the timing belt. I first changed my '01 after 10+ years and 183K miles (2 x the manual recommendation) on the clock. My '06 has 65K miles and I'm not even considering changing it in 2015. If the '01 survived 183K miles and 10+ years, a belt used a fraction as much will last many years beyond 10. But, I'm sure others have more conservative views.

 

Wheezer, this time dimension to belt change has been debated ad nauseam on this forum and there are many, many opinions. My own opinion is similar to Toms' and is to ignore the time period and keep an eye on the water pump. If you notice it leaking, even ever so slightly, get the belt and pump replaced pronto. Leaky pumps can seize and that is probably the most common reason for a belt failure. Otherwise, replace both at 90k. My 2002 LS has 64k miles and original belt. I am not even concerned unless I notice pump leakage.

I might add that your coolant does wear out and yours should have been changed several times by now. If not, your pump may not be lubricated properly.

 

Prolly gotta change the fluid anyway soon, if yur gonna keep the car a while and can get it done for like 600-650 bucks with a pump, all new belts I would get it done if yur gonna keep it. New Engine is "bank" "ca ching" but ya prolly yur safe.

 

600-650 bucks is like a routine visit for a BMW 700 series

 

Yeah, well I just bought a 2001 with 115k miles. As in, just got it 1 mo ago. I took it in a week ago for a timing belt change because I wasn't sure if it had been done yet. Within the last 10 feet of driving (super bad luck) the timing belt skipped and I, at the least, am looking at some valves and a head job. Just replace it, don't mess with the timing belt on these interference engines.

 

No worries about the belt. Especially with it being a Southern car. Probably garaged as well. I would do it at 90k or in the next 3 - 4 years. Do your plugs at the same time. They will be ready.

You are at a perfect mileage to do your transmission service. The Lexus recommended service on the transmission everywhere else in the world besides North America is 60k. Don't get me started why only North American devision invented the term "lifetime fluid"... Just have it done properly at the dealer or a good shop. Your transmission will thank you. Cleaning the throttle body and maf sensor is super easy and will also improve your performance and overall refinement of the engine. This really should be done every 15k - 30k considering how simple it is. Do it yourself when cleaning the engine bay.

 

So, the mechanic took the heads off and confirmed the damage?? If the belt did indeed 'skip', it might have been a bad tensioner. I would like to see photos and an analysis of exactly what component(s) failed.

 

am curious as well. TB failures are almost unheard of on this forum. Over on the LX470 forum they've had a couple and that engine is similar to ours; however, upon failure nobody reported engine damage. Which led to a debate as to whether these engines are truly interference engines.
personally i wouldn't hesitate to take it to 120k, or leaking water pump, whichever comes first.

 

Not sure exactly what component of the timing belt assembly failed first, but it did serious damage to the belt which caused the timing to skip. Only the drivers side head is off now and there are a few bent valves, but so far pistons/cylinders look OK. The other head should come off today or tomorrow to get the final extent of the damage.

 

ouch, that is tough to see Devlyyn. certainly looks like it just deteriorated.

 

I bought my 2002 used at about 40,000 and had the timing belt and water pump replaced at 123,000. Water pump was working fine and the belt looked almost brand new. No cracks in the belt, no visible wear to speak of, and maybe just the smallest amount of stretching if I recall correctly.

Still, with consequences (and cost) of a TB failure so high in these engines, I wouldn't tempt fate too much. I think 90K is probably too conservative. I will change my tensioner the next time I get the service done.

 

I bought my 04 LS430 with around 80K on it several years ago. Has 122k on it now. I still haven't changed the belt. Planning on digging into it when it's a little warmer.

 

All this Timing Belt talk made me order an Aisin TKT-021 kit. Will get my TB+WP service done this month at the Toyota Dealer.
I'll hold all old parts and maybe post a pic with the new part vs. old part, to see what wear is like after 100K miles.

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Changed mine at 10 years and 102k miles. Had them keep it so I could look. No cracks, ripples, anything. You could tell it had been used but I didn't see any signs of it "about to go bad." I could have easily gone way further, but I hear the 3-uZ is like a $12k motor, and the piece of mind is worth it.

If you dig up my threads started you can find the thread. I posted several pics of the belt.

Does anyone actually know how much a 3UZ would actually cost, new? Someone once said $18k on another forums.