How JustAnswer Works:
  • Ask an Expert
    Experts are full of valuable knowledge and are ready to help with any question. Credentials confirmed by a Fortune 500 verification firm.
  • Get a Professional Answer
    Via email, text message, or notification as you wait on our site. Ask follow up questions if you need to.
  • 100% Satisfaction Guarantee
    Rate the answer you receive.
Ask Chris(aka-Moose) Your Own Question
Chris(aka-Moose), Nissan Technician
Category: Nissan
Satisfied Customers: 621
Experience:  16 years of experience
Type Your Nissan Question Here...
Chris(aka-Moose) is online now
A new question is answered every 9 seconds

Developed a knock yesterday morning. At startup everything

Customer Question

Developed a knock yesterday morning. At startup everything is quiet and smooth. from 1000 to 2300rpm quiet underload, from 2300 to 3500rpm knocking(not a heat sheild rattle) unless I drop off the throttle then quiet. On cruise control at highway speed about 2000rpm a very light knock that is harmonic in nature
JA: While using the cruise control can you accelerate or decelerate? Have you checked the fuses?
Customer: (louder then quieter) if I turn on air conditioning it gets better but doesn't go away.
JA: What is the model of your '00 Nissan?
Customer: 2008 nissan frontier 4.0L 4x4 crewcab lwb SE
JA: Are you hoping to fix this yourself? What have you tried so far?
Customer: I haven't tried anything yet. I gingerly got it home yesterday and am developing a plan of attack now.
JA: Anything else you think the mechanic should know?
Customer: The knock is between 2000 - 3500rpm under load and not under zero throttle.
Submitted: 1 year ago.
Category: Nissan
Expert:  Jay replied 1 year ago.

Hello my name is ***** ***** thank you for your question

Since this is a noise, it is very hard to determine what it could be since I can not hear it. I have seen octane ping, exhaust heat shields and all sorts of things make noise under acceleration.

If you are stopped and you hold the brake while in gear and give the truck a little gas so it revs and tries to move when on the brake can you duplicate the noise?