Engine tapping noise
I have a 2003 Altima with the 2.5. At 25k miles I started to notice this tapping noise coming through the passenger firewall. Symptom exactly as you described and actually if you pay attention, it does not really go away even when the engine is warm/hot,just much lighter. Tapping/ticking away as you lighly accelerate from stop or low speed. Once the RPM picks up, it is covered up.
The tapping is more pronounce now that I have 35k miles. It almost sound like you have a mini-diesel engine when idling or at low RPM. You know that something is definitely wrong but it is not yet as annoying as bad lifters in engines with hydraulic engine.
I will say many customers notice that but are in continuous denial or the dealer send them off.
As far as I know and my diagnosis is that it is from the injectors. One thing for sure, it is a deteriorating situation. Something is wearing out prematurely inside the small injectors, causing the valve to stick, slap or whatever at open and closing. When something wears like this at this low miles while no engine maker will ever expect something like this NOT lasting the life of the vehicle (I will not even say engine) at this state and age, the problem is serious & troublesome. There is an inherent materials, manufacturing or design problem somewhere!!!
It has a high potential of eventaully violating the emission control standards when the fuel delivery cannot be consistently controlled, engine wear accelerate if gas leaks into the cylinder, the 2.5 has to be continue to power the new products plus so many on the road, but I think their biggest scare is emission and also news getting out to the market.
Nissan should be scrambling to figure out what to do. I think it is Denso's (Nippondenso) so called direct injection system. Do they know. OF course.
The engine is the heart of the car and your brand cannot succeed without a
couple of successful/good engine.
Only fools will not know that their heart is making noise, a real retard if he/she will say that there is no noise, and not a fool to keep quiet while working on it but will eventually be a fool to not eventually solve the problem for all the engines out there.
What I have done is to get the dealer to DOCUMENT that they hear what I hear, recognize the sypmtons and will fix it under warranty when they have a solution. I will be a gentleman to Nissan for now.
Dealer technicians these days are not mostly not seasoned mechanics especially Nissan since the Nissan dealership rebuilding is only 3-4 years old!!!
There older Nissan folks probably all jumped ship to other brands during those slump years. These are the younger guys these days in general and many are hired not for the sense and experience on mechanical stuff since gear heads are hard to find these days but for their lack of phobia on electronic controlled stuff and therefore can follow the manual & bulletins, which are selective info Nissan will pass on to dealers. What they know is mostly what they can read. Manuals cannot foresee and contain these these non-std problems. I find them see no evil and hear no evel until the beast is really belly up or a pice of bone sticking out of its body - really broken.
I do not know if Nissan has admitted to dealers and asked them to buy time or dealers are simply not capable of going beyond the book therefor innocently continue to say to everybody "I DON'T HEAR A THING and THE LITTLE tapping is NORMAL.
Will the engineers in Japan guarding the Infinite products or the Nissan chairman Ghosn allow himself to call this tapping normal and typical of a NISSAN 2.5L engine? and gamble the hard earned turn around to the injector tapping.
Hey KMOS: if you do not find a satisfactory treatment, communicate to Ghosn. There is a wish, no one can block you.
Last edited by kibatheloanwolf; 04-17-2009 at 01:04 PM.