Someone asked me if I could help them diagnose a strange noise on their G that only seems to happen on cold starts. It's hard to describe the noise. It's almost like a scrape or something straining. It lasts for about a second. It seems to come from the engine. I don't know what it is. I only heard it once and was inside the car with them, not outside trying to pinpoint it. Is anyone more experienced familiar with something like this or have experienced it on the VQ37 or even the VQ35? Your insights on where to start diagnosing it are appreciated.

 

Does it sound like a belt scraping?

 

Doesn't sound quite like that to me. Sounds possibly internal. Not certain only heard it once from inside the car. if possible when I next see him I'll try to have the hood u and listen directly as he starts it. Maybe try to record it.

 

Has the starter been replaced recently? Incorrect installation of a started will make this noise on many cars. Also inspect the engine bay and see if there is anything out of whack. Maybe have someone start the car with the hood open while someone is standing there to try to pinpoint the noise. There is just too many things it could be without knowing specifically what part of the engine its coming from

 

Does it happen during, immediately after, or after the cranking?

 

I'll check on starter replacement but I doubt it.

Happens immediately after cranking, at the end as the engine starts up. I'll see if I can get a recording if possible.

 

Could be the starter solenoid

 

I would think the A/C compressor clutch.

 

Belt I would go with Sam

 

Its a really high pitch noise, only goes on cold starts, loud as *** for a split second then quiets immediatly, yep definitly the belt. Nothing to worry about its jus condensation. It should go away on its own with regular vehicle use, drive it daily is what I mean. If not change the belt cause that would **** me off every start. I would imagine the vehicle has the belt to be checked or replaced on the next maintainace schedual. Try a anti squeek belt spray to verify I never used the sprAy b4 but it should stop the weird noise on start up I think. Hope this helps...

 

Timing chain tensioner? I know mine is gone. When I crank sometimes I'll hear a scratching noise. The tensioner can be serviced without taking the engine out, it can be found behind a service "port" in the timing chain cover.


This is off of a 350z, same concept