I was once listening on the radio and they were talking about the tensioner on the nissan. They said that there is a plastic on it or around it that break fastr, so it should be replace around 60k. What do you think about this? Sorry I didn't mean to high jack the thread.

 

That's a load of crap in my opinion, probably propagated by a money-grubbing mechanic that wants to perform a wallet biopsy on you. I haven't heard of a single person with a timing chain tensioner failure at that premature of a millage interval on a VQ35 motor.

Usually you start hearing about those sorts of things (at least based on other Nissan motor designs) at around the 100-120K mile mark at the very least. This was a problem with some of the earlier KA motors where the synthetic/plastic chain guides would wear out and cause a rattling sound when you started the motor up. The rattle would go away after oil pressure built up, but there were some cases where the bits of debris from the chain guide would plug up the oil pickup and cause oil starvation to the top of the motor. Again.... this was on KA engines, not VQ's and I haven't heard of this being any kind of a problematic trend on a modern VQ motor.

If you hear unusual rattling then there is probably a cause for concern. If it is the timing chain guides, you run the risk of the chain skipping teeth and doing catastrophic damage to the motor, and could risk the possibility of the chain wearing through one of the walls within the motor and causing coolant to spill into the oil or vice/versa. It very well could be something else though.

 

heard about the plastic piece breaking not sure if I should start there I just find it hard to get outta the car while im driving to listen closer lol it only rattles under load but sounds fine if it revs up in nuetral

 

This is correct. In specific, the upper valve chain guides are the biggest culprits due to the plastic guides wearing out because they are thin. But the main tensioner also has a few issues, particularly the plastic guide that fits on it - it sometimes (more often than you'd hope considering how many videos there are on it) has a retention clip break off causing the guide it's self to slide downward on the metal tensioner.

 

My moms boyfriend keeps telling me the 2003 Coupe has a timing belt not chain... Is he right or wrong? Everything I have googled says that the 2003 G35 Coupe has a chain and not a belt but he insists, someone please clarify?

 

As was mentioned to you in the other thread you posted in, the G35s use timing chains. There are however belts for the accessories (a/c, alternator, etc.)

 

All VQ35DE engines are equipped with 3 heavy duty chains, the primary, and the ones that link the cams together on each bank.. Typically they are good for the life of the engine, they do NOT need to be replaced every 60-100k like a timing belt. I would only replace them if you were experiencing cam timing codes and had ruled out the actuators/sensors.

Or if you had the front of the engine disassembled for other reasons and there was 100k+ on it.

However the TENSIONER should probably be replaced at around 100k miles.