Hi:
I am just curious.


Thx.

 

Timing Chain as with all the other GR series V6 Toyota/Lexus engines.

 

Anyone know what the 3.3L uses? Belt or Chain?

 

Belt. I had ours replaced at 92K and it looked in perfect shape.

I am guessing it could have easily made it to 105K.

 

wait so the new 3.5 uses a chain? why the heck would they from a belt to a chain?

 

umm less maintenance? Many new cars use chain.

 

Since we are into this topic, anyone know if RX330 V6 engine is interference or non-interference type?

If it is the former then it is very important to change the timing belt per Lexus recommendation as you dont want to wait until the belt breaks and causes engine damage. To me, the used of timing chain in the 2007+ RX350 engine is one of the reasons I opt for it over the RX400h that still use the 3.3 engine with timing belt. I am planning to keep this RX for >100K miles and I do not want to fuss with the timing belt job.

 

The 3.3L is an interference engine, which is why I changed it early.

 

i always thought chains were more troublesome, but then agian, my mechanical knowledge of cars ain't that great. do you have to replace the chain? and if so when?

 

yes, you have to replace the chain. The interval should be in your owner's manual. The old rule of thumb was 60K miles, but I'm pretty sure Toyota, and most modern manufacturers, have a longer recommended interval now.

 

A chain should be able to go at least 150K. I wouldn't push a belt past 105K.

 

I agree with "should". However, I can guarantee you that I would never leave one in my engine for that many miles. Far too risky.

 

Chains almost never need replacing, thats why they went to the chain. Even in years past the only time we ever replaced a timing chain was when we rebuilt the engine and that was because it was cheap and we were right there so it made would have been stupid not to.
Jeff

 

The decision of chain vs belt may have been driven by external factor [not just which is better].

Typically:

Chains have longer life than belts and if you can not provide access to replace the belt then you should use the chain ...[it could be accessibility / external design that could have dictated the choice.]

Chains are more noisy.

Belts are lighter.

Belts require a more precise tensioner.

Chains can operate the pully on either side (belts can only drive on the inside)

As the pully size gets smaller the belts can not have enough teeth to grab onto, as compared to chains.

Chains need lubrication while the belts run dry. This drives the cost up.

Trend had been to move to belts for high revving engines. We can speculate, but what is the real reason? There has been another thread about leak in the timing chain cover, that requires Lexus to pull the engine out.

Salim

 

Does the chain on the Lexus 3.5 engine need lubrication? Is that part of the maintenance?