I have a 2003 g35 coupe. It makes a really horrible sound when i first turn it on in the morning or after its been sitting for a few hours. Any ideas what the problem might be. I have posted a video on facebook and you can listen to the sound check it out. let me know what you think.

http://www.facebook.com/video/video....ideo_processed http://www.facebook.com/video/video....ideo_processed

 

it sounds like dry start to me. FRAM oil filters or others which have bad drain back valve will allow oil to drain back into pan. when you start there is no oil pressure to connecting rods until oil filter is then pressurized. change OIL to 10W30 with new filter immediately. harm may have already happened. you will know after oil change.
Since the mfg recommends 10-30 but still many people will use 0-30 which is too thin of a viscosity for this engine. My opinion. go to www.bobistheoilguy.com for more opinions.

 

I have been told different things. First i was told the timing chain. then i took to a shop where they said it was the timing chain tensioners. They had my car for a few days and replaced the tensioners. They put synthetic oil 5w30. I still have the same noise. I have to take it back to them. I will let them know to use a different filter and oil. Thanks for the response. Hope it gets fixed. that noise is just terrible.

I have also been told the valves arent good.

 

did you ever find a solution to this?? I have the same problem and they recommended replacing my tensioners as well.. still rattles like that on a cold start. I am sick of it already!! Thanks!!

 

i have an 04 g35 coupe. same problem with you guys. rattle sound on cold start. any solutions to this problem? need help. thanks guys!

 

my 2005 G35 Coupe has been making a horrible rattle sound on cold starts. After many trip to the mechanic and having the timing chain tensioners replaced, I have finally found out what is wrong with it (as I suspected all along). The VVT Sprocket is cracked in half. I don't know why these mechanics arent looking at these things!! I have seen several threads where people are being told it is the tensioners, it more than likely is not the tensioners. The sprockets are clearly visible if they even are looking at the chain in the first place.

 

Wow, you would think they would notice that. Probably just looking for reasons to charge more money. Glad you got it figured out.

 

I had the same problem, and for me the fluent flush fixed it

 

I have this problem too. I just bought an 05 G35 with approx. 134k on it. I was told it was timing chains/tensioners as well. I have a 2 year extended warranty on engine and transmission. When I took it back to the dealership the techs looked at it and "said" nothing was wrong, I know there is obviously. But I'm going to change over to a heavier weight oil since they used 5w30 last time and go from there.