joeydingo

I recently had some minor service on my 99 GS4 with 68k and the service guy recommended that I have the timing belt changed as the powertrain warranty expires at 70k. I know the factory recommendation is 90k for the timing belt, but my question is whether anyone has seen the belts break prior to that mileage on the Lexus V8 engines?

I'm kind of a maintenance fanatic, but certainly don't want to go replacing a belt that has no realistic chance of breaking before the factory recommended change point. On the other hand, I'm wondering whether this might be a case of "better safe than sorry" when I read about the damage that can occur when a belt goes on an intereference engine..................

RTIS250

iTrader: (9)

In all reality, ive seen belts go to 120k+ miles. At 68k, i wouldnt recommend replacing it. Just wait until 90k. Even at 90k, when i recommend belts due to "age and milage", the belts dont look to terrible.

gserep1

Hello,
Don't waste your money. This is a scare-tactic. I have never heard of a belt breaking before it was due to be changed at 90,000 miles...even with people hot-rodding the car regularly. The belt has a fudge factor built in. In all the Toyota belts I have changed, I found the belt in better condition than I thought, and I know they could have gone further.

The only problem with the GS engines is that the water pump is turned by the belt, and if the pump goes, it will either spill hot collant onthe belt if a seal goes, or if the bearings seize, the cams will instantly go out of time, and could bend valves. So change at 90,000 miles, even though it could go HUNDREDS of thousands of miles in my opinion. Keep the proper antifreeze in and change it regularly, and you should have no failures in between change intervals. Coolant change, and maintaining proper PH balance in the cooling system is the key to long water pump life. Rust and corrosion in the system is because the alkaline balance was disturbed, and the radiator as well as all other parts iof the system have been compromised.

I changed my timing belt last year on my first 99 GS4 along with water pump, bearings, tensioner, and thermostat, and everything looked in great shape before I started. There is so much to remove to get to the belt, that is it cheap insurance to change it while inside the engine.

Drive it to 90,000 miles with confidence. In fact, I should have driven my spark plugs to 120,000 miles or more before changing them. They were not worn out at 90,000 miles..... In fact, I still HAVE my old plugs, and could use them again if I needed to.

PERRYinLA

Well put, and may I add that the older V8's of the early to mid 1990's are non-interference, meaning the valves won't bend/break even if the belt snaps. All that will happen is you will need a tow. If you can live with that (and I sure can- that's why I have AAA), then you can go well into the 6-digit mileage range with the original belt.

techsc400

iTrader: (6)

Does anyone know that 95 V8 engine (95 SC400) is non-interference or not? for sure?

Well put, and may I add that the older V8's of the early to mid 1990's are non-interference, meaning the valves won't bend/break even if the belt snaps. All that will happen is you will need a tow. If you can live with that (and I sure can- that's why I have AAA), then you can go well into the 6-digit mileage range with the original belt.

VVT-i

The 95 SC400 is a non-interference engine. The SC400 got the upgrade engine from the LS400 in 1996, the 1995 LS400 got the 2nd gen 1UZ first.

techsc400

iTrader: (6)

Great!. My 95 SC4 hits 75K miles. I plan to change the spark plugs(iridium, so I do not have to change it for long) and clean the TB on 80K since it is recommended at 60K.
But, I will drive over 6 digits and change the timing belt, water pump, etc.

Pearlpower

iTrader: (2)

These timings belts are HUGE. I have seen one go over 170k on the first belt!
However, it was missing some teeth and the owner was very lucky it did not go.
I change mine every 75-80K miles due to my driving and now my increased HP.
Lee

techsc400

iTrader: (6)

I meant by cleaning the TB (Throttle Body).. I also meant by 6 digits as (until 100Kmiles).
I will change the Timing Belt when it hits the 100K miles. I know that it is recommended at 90K.
Since it has a NON-interference engine, I will put 10K more miles. Make it as 100K miles interval.
Easy to remember!

disc108

I just changed my timing belt on my gs3 at 94K miles and it looked fine

gcrim21

Service representative at Sewell Lexus in Dallas said no reason to change the timing belt until 100,000 miles unless the vehicle has been driven under 'extreme' conditions....heat, hard driving, etc.. Also told me to never flush the transmission fluid, only drain it every 30,000 and 'top it off' unless the fluid turns purple (opaque).
He also recommended replacing the water pump, bearings, tensioner, and thermostat while everything for changing the belt had to be removed and would be less expensive in the long run.
Another thing is he said ..... in the 'official' service manual, the irridium spark plugs did not need replacing until 120,000.

GCrim21