FYI
A interference motor means that if the timing belt/chain breaks the valves will more than likely hit the piston and cause more damage.

A non-interference motor means that when the timing belt/chain breaks the valves will clear the piston and no damage will occur.

Is the GS400/430 a interference or non-interference motor?

My car was built in 9/97 and only has ~56K. I wonder if I should move up the maintenance schedule. My dad did the 30K at 24K when it was 4 years old. I did most of the 60k(didn't do the plugs) at 48k when it was 8 years old.

Anyone know if the timing belt is Kevlar reinforced like some of the newer timing belts.

My sister broke the timing belt in her Dodge Avenger 2.0 DOCH twice. Both times bending valves and both times it happened before the scheduled replacement time for the belt.

 

GS4 is definitely intereference (don't know about the GS3).

This is a great thread. Thanks guys. It's interesting, because in all the 90k service threads I've read during my research, no one ever seems to mention replacing the pulleys. If it weren't for Sewell Lexus, I wouldn't have even known that those were something to think about replacing.

 

Same here on the California coast. When I contacted Carson Toyota about the timing belt on my first GS400, they recommended these pulleys. I never once thought they were just trying to make money.

A lot of us have a cavalier approach when it comes to the quality of Toyota parts. I KNOW they are good, but I don't push the envelope. I drive from San Dtego to San Francisco twice amonth, in cold weather and hot. I want the car to perform and not break down on the road in between either place.

40,000 miles per year is not uncommon, so peace of mind is important to me. I do the work on one end or the other, but I have never broken down on that lonely 1000 mile roundtrip in 35 years.

I like to do good maintenance, and it pays off in no unscheduled breakdowns when I need my car the most. So spend it now, or spend it when you least expect it.

This is a great place to air your opinions. All are welcome.

 

I'd like to share a story with you that we have at our shop.
98 GS400 with 121k miles. Client coming in for the timing belt replacement. We advised her to change out the water pump and pullies while we were there. She declined the work. Five months later, we received a call from Mrs. XX saying that her water pump went out. It overheated the engine and damaged the entire block. She was on her way to Florida. If she could took our advised and replace the suggested items then it wouldn't cost her $10k. The 10k was for engine replacement, rental car, the fly back to dallas and for shipping to ship it back to dallas. Lexus is a great company and their parts are great. But parts do fail, When will the water pump fail? You don't really know. Replace the water pump as suggested according to lexus.

 

I changed mind with koyo. Its look the same as the dealer part even the part number on it, Just different box. But the price can not compare.......70>>>27

 

If you are not sure what are you doing so i would say dont do it because VVT-i parts is not friendly. If you made mistake it cost a lot of money

 

I agree,
And THANKS JPI for your story. It just reinforces the old theory I have of paying NOW instead of paying later. 10 grand is a lot of money for an engine and all the associated expenses with this repair. Plus you LOSE YOUR TIME! There is nothing you can do to get that back. This is very inconvenient.

When I was down to the water pump after taking off the timing belt, it was not even debatable if I was going to change it or not. I had the time then, and I fixed it right, as most of us do.

The car in question was a 98 GS. This was the first year of this engine in the GS, so it had been on the road a long time. The way the lady reacted to spending a few extra dollars spoke volumes to me about how well she possibly had taken care of the car. How much else had she scrimped on in the belief that "Lexus makes good cars?" You gotta MAINTAIN them to KEEP them reliable.

I think that the red coolant Toyota has for this engine is top-notch. It still needs to be done every 60,000 miles to keep the cooling system in shape. She could have possibly had deteriorated, worn out coolant, which contributed to the demise of that pump. Maybe JPI didn't put in any coolant when they did the timing belt, and she went on her merry way. This is most unfortunate. Hopefully she won't blame Toyota / Lexus, and call the car a piece of junk. She kept it and fixed it, so that is a good thing. It is amazing how we have 10 grand for a new engine, but not 100-120 bucks plus labor for a new pump.

Once again, I think that the pump should be able to go further if properly maintained, but HOW MUCH further is the question.

Perhaps I was wrong in the assumption that a leaking pump will dump coolant on the timing belt. I stand corrected. Since I drive so many miles up and down California all year long, I would not want to have an overheated engine on the road. Much of the 1UZFE engine is aluminum, and severe damage will definitely occur if it gets too hot.

This lady may have also driven for awhile on this hot engine causing further damage before she figured out that the car was hot. Seems like she melted a few parts.

This gets me to wondering if we have a system in place like the majority of the newer cars that will drop our engines down to 4 cylinders and use the other cylinders to cool the engine down, and then cycle the other 4 cylinders?

This "LIMP HOME" feature is common on all Cadillac Northstars since 1995, as well as all the Ford Modular V8's of 4.6L and 5.4L variations. I may check into this.

JPI, you are pretty knowledgeable about such things. Do you know if we have that or not?

Thanks, and I will be watching for a reply.

 

Coolant level was ok when the vehicle left the shop. Look like it hasn't been flush out for a while. Again, Coolant flush was declined!
Unforturnately, We don't have the special feature like Cadillac do. But Lexus do something which I think really neat. We have a little stainless steel pipe come off the head, This pipe will blow up when coolant temp get to a certain temp and the car would shut off by itself.
JP Importz