Noises problem on my 2004 g35 coupe

To make this short I have an annoying rattling in my g35. When I take off in first my car rattles until I hit about 3k rpm. It does it as well if im already traveling at speed and have to slow down and if i dont downshift and have to start off again in low rpm it rattles until im in the 2.5k-3k rpm range. It just rattles and its annoying!! could it be some loose part on my exhaust?

 

oh ya it only happens when the car gets warm, on start up it makes no noise

 

Two things it could be, one cheap, one not so cheap:
1) Heat shield. Very cheap, probably just some loose bolt, vibrating with the engine and hitting the exhaust.
2) Cam bearing. Just found out mine was toast today, and yes, every exact symptom you mentioned was happening to my G. Would rattle between 2-3K rpm, after it gets warm, but not when the car is first started. The bad bearing would allow the timing chain to become slack, and the tensioner would try to make up for it, but under those certain rpms, the tensioner would just bounce against the case, causing the rattling noise. Mechanic quoted me $2100. Better luck to you!

*Edit -- Found out it was a broken timing chain tensioner, and the bearing is fine. Still a PITA, but at least you can maybe work on it yourself if that indeed is the problem.

 

Additional note, it will run and drive just fine with the bad bearing, but eventually it will get worse until the cam is so out of line a piston will hit a valve, and we all know the results of that...

 

How much did they charge you to replace the tensioner? and is it easy enough to change it yourself?

 

Ha, they charged me $2100 to replace the tensioners, all three timing belts, and the water pump. I said thanks, but no thanks. Looked online, found some good diagrams and how-to's, but you basically have to pull the whole thing out to do the work. Decided it wasn't worth it on my 165,XXX engine, and will just run her until she dies. Crap, a used engine is only $2,500ish, so when it comes time, I'll just plop in another engine. Below is a useful picture, pm me if you want the instructions. Good luck

 

Oops, sorry. Here's a link instead, with the instructions.
http://www.nissanforums.com/a32-1995...ing-chain.html

 

Yea no thanks! 2100 to do the work I rather buy a new engine.
I heard of people talking about this and no one has DIY! I wonder though if its possible to just take off the front plate cover for where the tensioner sits at ya know. I going to open it up to see if its possible to just do it that way with a “short cut” even though it might not be the best idea. ( I learn from my mistakes…)

And thanks for the link too.

 

Found this. It shows you step by step on how to replace your water pump (and get to your timing chain tensioner). See attached

 

Does it sound like this?
AUDIO LINK
I had a zoomH2N mic taped under the drivers side control arm brace. Pointed towards the exhaust.
It sounds like rattling where the exhaust or the transmisson is.
I have to press the gas pedal at the right angle to hear it for a lenght of time.
I beleive it only makes the sound when the car is warmed up.
Any ideas?
I hope its just crakling of an exhaust?