alaincuadot

First of all I apologize for my terrible English. I speak SPANISH. Hi all, I have a 1996 Nissan Maxima, which I bought with a bad engine, I changed it a few months ago. After a while I felt that the car makes like a noise that is like you are giving me strokes under carriage, the sounds are bass I compare them with the sound of a rubber hammer, so, sometimes it feels like the car is going to be off but it never happens. It does so only when I'm stopped at a light, never when I'm accelerating, ie running. I tried to put it in neutral to see if it comes from the transmission but it continues doing it. Sometimes it does it few times, sometimes it does 15 to 20. Simple, as if I were giving blows with a rubber mallet under the seats, in the front of the car.

I've carried two mechanics, they put computer, they had problems with the Knock sensor and put it back brand new, had problems with the Mass Air Flow sensor and put it back brand new too, but the problem remains the same. Something important, when I start the car and the engine is still cold no noise at all. Only when it is hot.

More than a real loud noise is something you feel beneath the cars, itīs more like knocks than noise.

If someone can suggest something? I'd appreciate it. Thank you all.

asand1

iTrader: (1)

Sounds like it is backfiring, Possibly from a lean condition or bad coil(s). Is the check engine light on? The knock sensor will often wrongly show a code. Were there other codes? The actual codes would be helpful.

alaincuadot

No, nothing like backfiring. Sounds like a (Golpe en espaņol), like a hit, strike, punch, knock, I donīt know how to exactly describe it in english. The chek engine light is OFF. The knock sensor was changed. Iīm going to try to get the codes because I donīt have the computer. Thanks a lot....

alaincuadot

No one can help ?????

asand1

iTrader: (1)

Does it sound like the engine knocking? or suspension banging around? Try to find a you tube video with a similar noise and post a link.

njmaxseltd

iTrader: (19)

Engine knock, on a failing engine, starts to appear when the engine reaches operating temp.

JvG

Does the engine vibrate back and forth a lot when it is in neutral?


I am thinking that the engine mounts could be bad.


Other members chime in please...

alaincuadot

There is no problem with the engine, the mounts were placed new on February 2014, qhen I changed the engine. I canīt find a video in youtube with it, anyway it does not sound so loud to be able to hear, is more a feeling, something you feel beneath the car, and it is only when I stop in a light..... no sound when it is moving