Hello scotty,
As stated in the title, I have a 2005 Nissan Xterra and one day, out of nowhere, it started to have a weird knocking which I can feel in the footwell. The car has 180000 miles on it. The engine runs all good, the transmission also runs decently, given it has 180000 miles on the clock. I checked the suspension and everything seems fine, nothing out of ordinary. Motor and transmission mounts were checked and are also fine. The knocking can't be heard from the outside, only inside the car. The car has absolutely no problems with starting, idling or driving. Nothing has changed car behavior wise.
situations when it can be heard:
1. While starting the vehicle (faintly).
2. While shutting the vehicle off (faintly).
3. While going over bumps (can be heard very distinctly).
The knocking stops when I'm going on the inclined road, if I don't run over a bump. There is another thing. One day I was working on the car and I dropped a wrench in the engine bay on the passenger side, which I couldn't find, till this day. Happened over 2 weeks ago. knocking started 2 days ago. I really hope that that's the case and nothing serious. When I accelerate the knocking seems to stop. The knocking can be heard and felt only in the driver side footwell and nowhere else.
I bought the car used, from an owner. I don't know which dealership did the guy buy it from in the first place. I'll say it again, car runs fine and shows no other problems. I really can't say what else can I do, or check, or what else to look for to find out what is causing this knocking.
Check for separated engine and transmission mounts. They corrode and fail over time. Check for properly torqued mounting bolts, etc.
Thank you for the answer. I checked every mount and they are all fine. The engine doesn't shake, nor is the knocking noise effected by the engine. When I rev up the engine the noise stays the same, sometimes even stops. I'll check them again just to make sure.
You’ve got to find that wrench and rule it out as being the culprit..
If only it were an easy task. I can not see it anywhere in the engine bay. I have to assume that it somehow ended up above the transmission, got stuck there and now bugs me all day. Only way I can make sure of that is to pull the trans out and that is not a cheap work. If only I had the tools needed for that, Could do it myself.
Sorry for neglecting the post for this long. Been caught up in diagnosing the problem. The update is that, I ended up changing the motor mounts and the trans mount. The wrench that I dropped in the engine bay is gone. It is not there. The knocking, or should I say, kind of rubbing/knocking sound now, still persists, only when I start the car, or turn it off, or drive on bad road conditions (not during the cold start, only after driving for some time). Still can't be heard from outside, only can be heard from the inside of the car, on driver's side. I am starting to believe that it is somehow connected to the suspension parts. The struts are in good condition, so are the control arms. The ball joints are also in good condition. Could it be somehow connected to the sway bar or the sway bar links? maybe the bushings are starting to wear out? I had doubts that it could be the steering column for some time, but the steering feels great and has no problems. I did find out, during the diagnosis that the brake calipers are a bit loose, but can they knock during starting, or turning the car off? I am terribly confused. I have never met this kind of situation in my experience with cars and this is my fifth car now. Can't even find a mechanic that can pinpoint what could it be. Most say that it might be a rock or something stuck in the chassis, but I still don't think that way. I've Been also lurking in numerous forums and can't find a similar problem.
Hello again. I also took a video showing the knocking sound. Here is the Youtube link: https://www.youtube.com/watch?v=lCq0EabOF1o