Possible exhaust leak

[cramblda]

Sometime in the last couple of months, I noticed a subtle, but slight change in the sound of the engine on startup. Normal engine startup is smooth and instant. Now there is a very, very slight hesitation and a "slightly off sound", a little like "lope" from an aggressive camshaft in a hot rod engine. The engine seems to sound normal after startup.

I recorded this sound clip linked below, hoping it may be more helpful. Around 5 seconds in, is a good example. Unfortunately, the sound didn't come through as clear as I would like. There seems to be a lot of "airy" background noise, that is not present when hearing the engine run directly.

https://soundcloud.com/david-cramble...ti-qx56-engine

I have seen references to exhaust manifold cracks in the Armada, QX, Titan, etc - but none for this late (2008) of a model year. The truck has 120K miles on it now. I recently had new NGK Laser Platinum (factory spec) plugs installed. The sound existed both before and after the new plugs.

 

[marctronixx]

just because its not been on an internet forum, does not mean it does not exist!

if the sound goes away once it warms up, its possibly cats and/or manifolds...OR maybe even the timing chain (huge thread on this already).

if you are not the original owner, the car could have been through hell prior to your purchase..

 

[cramblda]

just because its not been on an internet forum, does not mean it does not exist!

if the sound goes away once it warms up, its possibly cats and/or manifolds...OR maybe even the timing chain (huge thread on this already).

if you are not the original owner, the car could have been through hell prior to your purchase..

Yeah, that's why I made the post. I was hoping someone else may have already been through this and had some helpful information.

The sound goes away immediately after startup. However, we've all but confirmed it's a leak in the drivers side manifold or down pipe before the cat. We've probably caught the leak very early, so there is no noticeable sound after the car is running at this point.

I could be wrong, but I believe the timing chain issue is on 2011 and newer models. This is a 2008.

We're the second owner, but we have had the vehicle for 3 years and 50,000 miles. We also have detailed service records from the dealer for the first owner period. This truck has had very few issues.

 

[marctronixx]

its manifolds and cats then. i did not pay attention to your year. my bag.

search nissan armada and cats/manifolds. same car.

______________________________

 

[roughyear]

Strange... I thought once there is a leak in the exhaust, the sound stays and stays.. never thought it would quiet down after it warms up

 

[marctronixx]

in the manifolds on the nissan rides, this is indeed true (cant speak for other brands as ive been mostly with nissan over a decade plus and have read lots of data). tons of folks over the interwebs who will attest to this.