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 Matt Your Own Question
Matt, Engineer
Category: Nissan
Satisfied Customers: 20364
Experience:  BEng hons Mech engineering, worked in auto industry for 22 years on engine, transmission and suspension design
Type Your Nissan Question Here...
Matt is online now
A new question is answered every 9 seconds

A cracking sound on the engine exp when I drive at over

Customer Question

A cracking sound on the engine exp when I drive at over 120km/h. At low speeds there is rattling noise and disappears as you accelerate.
JA: How many miles are on the car? What size is the engine?
Customer: Np300 2.4 132000 km now.
JA: Tell me a bit more about what's going on so he can help you best.
Customer: At low speeds a rattling noise initially I thought it was from the gear box. Today as I accelerate trying to go beyond 130km/h A loud cracking sound evidently from the engine was heard.
JA: Are you hoping to fix this yourself?
Customer: What might it be? Wanna the cause first
JA: Is there anything else the Nissan Mechanic should be aware of about your Nissan?
Customer: Just that
JA: OK. Got it. I'm sending you to a secure page on JustAnswer so you can place the $5 fully-refundable deposit now. While you're filling out that form, I'll tell the Nissan Mechanic about your situation and then connect you two.
Submitted: 4 months ago.
Category: Nissan
Customer: replied 4 months ago.
Posted by JustAnswer at customer's request) Hello. I would like to request the following Expert Service(s) from you: Live Phone Call. Let me know if you need more information, or send me the service offer(s) so we can proceed.
Expert:  Matt replied 4 months ago.


I'd start by checking for exhaust leaks before the O2 sensor as if this has been experiencing an exhaust leak then it will have been running very rich as the sensor will see the extra air pulled in as fresh / lean fuelling and be adding fuel to compensate.

this can lead to catalyst failure as the extra fuel can re-light inside and melt the catalyst

The best way to find an exhaust leak is to run the engine from cold and feel around the exhaust joints with your bare hands - you'll have about 30 seconds before it all gets too hot and you should feel any escaping gas blowing over your fingers

Customer: replied 4 months ago.
Can you please stop debiting my bank account. I don't think I got any assistance. If this persists I will report that as fraud.
Expert:  Matt replied 4 months ago.


I see that you're not satisfied with my answer ?

how can I help further?

Related Nissan Questions