My engine has been making some knocking noise every so often. It happens especially when I accelerate from a stop and when I turn the engine off. The knocking is synchronized with engine RPMs. So for example, when I turn the engine off, it will go knock-knock-knock--knock---knock----knock-----knock, getting slower and slower until the engine stops. Free revving usually sounds normal, but intermittently the knock/tapping can be heard.

I fear that this could be the dreaded rod knock in which case I would need a new engine. But I bought the car private party (stupid, stupid decision) and there is no warranty on the car.

What are my options? Do I take it to the dealer for a diagnosis? Do I take it to a regular mechanic? Is there any DIY tests I can run myself? I'm just trying to avoid having to spend a fortune, especially if it's just a diagnosis.

I'd appreciate any advice. Thanks.

 

Unfortunately that doesn't sound good. Typically most dealerships will charge you 1 hour of labor for diagnostics. Depending on their rate, about $125-150 or so. An independent shop's rate may be half that. Or some might make an initial diagnosis like this for free. However the dealership will credit the diagnostic fee toward the cost of the repair if you have them do the work.

 

Also, if you think it's a knocking rod, Google "VQ rod knock" and check out the videos and listen to what it sounds like.

 

You should have paid a Infiniti dealer their one hour labor rate to check out the vehicle prior to purchasing from a private seller.

Just my $.02

Telcoman

 

I disagree. An Infiniti dealership has a vested financial interest in you buying the car. Not impartial. An independent inspection service who does pre purchase inspections is a better option IMO. They aren't looking to encourage you to buy a particular brand so as to make money on service down the road. But he's already got the car now, so this is getting off the point. Now he needs to know what's wrong with his car and what it'll take to fix it.

 

What BB said^^.. I had some work done and the hourly rate for Infiniti diagnostics is $125.00.. But they cut me a break when I allowed them to do the repairs as well