Is the 3.4 an interference motor?? I was reading on another site where someone said it is. When should you get the timing belt replaced?

 

Don't wait till it's to late. If that belt breaks so does your wallet. Replace the belt every 60K or so. It's called insurance.

 

I don't think any of Toyota's engines are interference motors. Now Hondas, that's another story.

 

The 20R, 22R, 22RE are interference engines.
When the timing chain breaks, it can destroy your engine with a hole in the side of it.

The 3.0 & 3.4 are non interference engines meaning that if the timing belt breaks, the engine stops.
No damage to other internal parts.

 

I think 22r and 22re are interference motors.

I think it's:

timing CHAIN=interference,
timing BELT=no interference

Not 100% sure though.

 

Isn't the new 4.7L V8 an interference as well? I think someone mentioned that???

 

toyota's with belts are not interferance motors, as belts are designed to break, chains are not

from the 16r to the 22re are all interferance motors, not sure about earlier.

 

How about the 5VZ-FE V6/3.4L? Which is it?

 

Yeah that's what I meant. Since chains don't break that often, i didn't think of those.

 

OK, so the 3.4's aren't interference. How about the belts?? When should you change them?? When I bought my truck it didn't have an owners manual with it. I was told 90K once and I've heard others say 60K. I am Ready to hit 80 thousand and was going to get it done here soon. Am I overdue?

 

I did some extensive checking back early in the year on this very question about the 4.7 V8., prior to getting a 2003 V8 Limited Runner. I checked with my mechanic, the Gates rubber company and several other sources and the answer I found was: The 4.7 litre V8 is an NON INTERFERENCE ENGINE.

 

Service Manual: Replacing the timing belt on the 2UZ-FE (4.7 liter V8) page 14-109:

"Notice: If the timing belt is disengaged, having the crankshaft pulley at the wrong angle can cause the piston head and valve head to come into contact with each other when you remove the camshaft timing pulley and camshaft, causing damage. So always set the crankshaft pulley at the correct angle".

 

Nope they aren't interferance motors.... they reccomend every 60k for the belt. The water pumps usually go about every (2) belt changes (120-150k), so inspect that while your at it. I went to about 80k in the wifes Tacoma before I changed hers. It's all hand tools except for the tensioner, that takes a Toyota tool to make the job waaay easier. If it hasn't broken then your not really that overdue for one, are you? Not a big deal... couldn't hurt to have it done though.... and no it won't kill your motor if it breaks, but it WILL leave you where it breaks.

 

The manual says 60k for inspection on the belt in my 3.4, Ive talked to 2 service managers and many toyota guys and everyone said 90k is a better one to aim for and to go ahead and get the water pump changed then also. Mines at 52k now and I plan on changing the belt and pump at 90k.

 

if you have a 3.4 and you are getting a new timing belt, spend now and do a waterpump at the same time. Chances are its already seeping inside the cover.

MJ

 

This is incorrect.


Interference has nothing to do with it being a belt or a chain. For example, the 2.7L Tacoma/4Runner/T100 motor has a timing chain, and it is non-interference.

An interference engine is one where the valves,when open, will touch the pistons at TDC such as when the camshaft timing is out of sync. This could occur if the timing belt or chain breaks, is incorrectly timed or someone is moving the cam or crank with the engine not fully assembled. A non-interference engine won't do this.

 

here is a good pic



http://www.gates.com/img/brochures/interfer.jpg

 

Right, it has to do with design philosophy.

 

I believe Toyota recommends 90k for 1998 and up models. I did mine at 60k anyway.