3RZ-FE I4 Timing Chain Guides?

So I know there isn't any replacement interval for the timing chain and it doesn't need replacement unless something drastic goes wrong.

However I've heard/read of how timing chains usually have plastic guides that may break causing the chain to stretch. This would causing timing to be off and possibly the chain jump a gear tooth.

Does anyone know if the guides are plastic and what there reliability is? Or if there are any guides at all?

I've read how the 22R engine's plastic guides could break leading to problems I mentioned above and even wear through the cover b/c the stretched chain would hit against it, as well as valve damage from piston slap b/c off timing. The 3RZ isn't an interference engine though so know valve damage could occur but I suppose a stretched chain.

 

I have yet to here that the guides fail prematurely on the 3RZ-FE engine. Typically all chain guides have a metal base with a plastic friction face for the chain to ride on. The 22re was a unique situation where the base was plastic also, the plastic base broke and the guide fell out of position. I have 2 timing chain type Toyota vehicles in the 90,000 mile range with zero issues, my buddy has a 2001 4-cyl Tacoma 4-cyl with 195,000 miles and he has never had any issues either. With proper oil maintenance the chains and guides should last a long while. Hope this helps.

 

this.

IIRC when I replaced my valve cover gasket the timing chain guides were indeed metal w/ a plastic face. They may have even been all metal...can't remember. I do remember clearly though that the guide had almost zero wear and my truck has 175k and has had no problems w/ the motor.

Dont worry about it drive the piss out of it like we all do

 

k thanks for the info, it would make sense to have a non-metallic surface on a metal base for the chain to actually run against so neither the chain nor guide surfaces wear down that much.

 

I too have a 3rz and I'm hearing a rattle/tapping noise when I start the engine. Its only when I turn the key and the engine is trying to crank. After the engine cranks, the noise goes away. Could this be a timing chain or guide issue?

 

My truck has a tick/knock on start up. Nothing to worry about. Timing chain motors are noisy by nature.