07 4.0 timing

[Megaton]

anyone know if the timing on a 4.0 can be checked with a timing light?  I've had a major drop in power and my mechanic says it could be the timing. 

[hawairish]

I'm inclined to say yes since there's instructions in the FSM to do it on the 3.5L; same process as you'd expect with the #1 coil.  However, even if you know the timing, I feel like the nature of the VQ prevents you from making any sort of adjustments.

 

Notably, a decent OBDII scan tool can return the timing advance value if it supports Live Data views.  I've been face down in my scanner dealing with BS on my R50 lately and have been monitoring that, among many other things.

[Slartibartfast]

 If the computer is pulling timing, it's probably got a reason. I would start with the scanner, live data and codes.

 

Only other thing I can think of is if it's jumped timing. I wouldn't expect a chain to do that, but I do remember reading about some chain guide issues on the 4.0. I don't know the VQ, but the 2UZ-FE in my dad's Yota ran poorly with the belt one tooth off, and not at all two teeth off. (A mouse found its way into the timing cover, and had a Very Bad Time inside.) Threw a cam sensor code IIRC.

 

[hawairish]

Now that you mention it, there were timing chain guide issues in early 2nd Gen Xterras, but not sure if it bled into Frontiers and Pathfinders, but seemingly plausible. The guides wore prematurely and caused rattle noises. Don’t recall seeing much about them manifesting into timing issues, since the noise was fairly obvious of an issue. 
 

Personally, I go the scanner route.  Mine supports live data, but also shows pending codes. Presuming they all do. 

[Slartibartfast]

Yeah, I haven't heard of it happening, but figured it might be worth mentioning. My cheap OBDII scanner shows live data (no graphing or anything special) and pending codes. 

 

 

[adamzan]

21 hours ago, hawairish said:

Now that you mention it, there were timing chain guide issues in early 2nd Gen Xterras, but not sure if it bled into Frontiers and Pathfinders, but seemingly plausible. The guides wore prematurely and caused rattle noises. Don’t recall seeing much about them manifesting into timing issues, since the noise was fairly obvious of an issue. 
 

Personally, I go the scanner route.  Mine supports live data, but also shows pending codes. Presuming they all do. 

It did happen to the pathfinders for sure. My grandparents neighbour had an 08 and we had to do the timing set on it, and it had around 80,000km on it.

 

My father has a 2012 X that he bought new had had to have the timing chain and guides replaced on it at 180,000km... The timing belt on his old 2000 r50 lasted longer haha.

Edited August 27, 2023 by adamzan

[Megaton]

Thanks for the info. My mechanic is a former Honda mechanic and he doesn't know to much about Nissan. This should help him.

[Megaton]

Finally got to the bottom of the problem. It wasn't exactly the timing, however, the tensioners were at their limits. It was clogged catalytic converters.