Nissan Repair Questions? Ask a Mechanic for Answers ASAP
Hi there, Thanks for using justanswer.
Could you explain the noise in a littler more detail for me? Does it sound like a chatter from the top end? is it more of a pinging sound? or is there a squealing?
Let me know so i can further assist you.
Hi there. No nothing like that, just a heavy coarseness at around 3-3,500 rpm which reverberates inside the car. It's like having a blown exhaust, but coming from the front. Most noticeable under throttle, trailing throttle reduces the noise considerably at the same speed. I can drive through it, but need to be doing 75mph + for the noise to be the same is if doing under 58mph. If it was the manifold leaking, would it not be noticeable all the time and would not dealers have picked this up. Also can feel slight vibration through steering wheel and body in tune with the harshness of the engine. Regards
Thanks for the detailed response from my info request. You explained the symptoms very well.
Because the vibration and harshness is only at certain speeds (correlating with engine RPM), we can conclude that it's likely to be related to 1 of 2 things.
First and most likely concern would be in regards XXXXX XXXXX exhaust system. Exhaust notes change as exhaust flow and pressures increase and decrease. Similar to when you try to accelerate in a higher gear and get excessive bogging an vibration. An exhaust leak will only increase noise and vibration. I would assume that at the speeds your experiencing the symptoms your at a relatively low RPM because of transmission gear and vehicle speed. Is that correct?
The second thought and less likely culprit would be Engine or transmission mount problems, but generally these are noticeable at idle and acceleration. Cruising speeds usually don't increase harshness in response to a mount that's failing.
So the first thing I would do is check the exhaust for leaks, including the manifold. Verify the heat shileds are tight as well.
Let me know what other questions you have so I can continue to help you.
Thanks for this. Visit to exhaust centre this morning and they say, without looking at car, it can't be the exhaust. It's so frustrating. I may just give up and sell the car on. Appreciate your comments. Paul