2000/5 speed/58k miles.

I bought the car a year ago with 37k and for many thousands of miles I've had this same issue. I want to get it possibly resolved now because in 1800 miles my powertrain warranty is up!

I can best describe the issue as such:

When in 3rd gear accelerating between 2500-3500 RPM I get a rattling from the front of the car. This rattling is NEVER in 1st or 2nd gears and is rarely (but sometimes) in 4th and 5th gear. The rattling manifests itself best in 3rd gear when accelerating up a hill, or on to the highway. If I accelerate onto the highway up a hill that's when the problem is easiest to notice.

More times than not the rattling does not happen, but sometimes the car gets in a mood where it wants to rattle (seems to have nothing to do with engine temp or how long I've been driving). MrsSkoorb tells me that the problem is getting worse, since she drives the car quite a bit, and whenever I'm driving I seem to be swamped with a lot of traffic, so it's hard to replicate.

The rattling is not particularly loud, but otherwise it's difficult to describe. Any ideas are appreciated, because taking it into nissan service right now I presume I'd be quite possibly unable to replicate it, unless the car is in one of its moods. BTW It comes from the front somewhere

If you are sure of what this is what do you project repair costs to be (if any, since it's under warranty)? How should I approach nissan service?

 

No ideas?

Since it generally only wants to happen around the same speed normally and in the same gear (for the most part). I'm thinking now that it's probably something loose somewhere that likes to just hit the right frequency when I'm a) At the 2500-3500 RPM range, and B) At a certain speed...too little and it doesn't go off, too much and it does.

But then it also does prefer it when I'm going up hills.

BTW the rattling is kind of a light or small sound as opposed to a large object.

 

OK the sound is definitely from the front right of the car and sounds almost like it's coming from the wheel well, though admittedly identifying this while going at 40 from the driver's seat is hard

 

Free bump.

 

is it pinging?... if it is, it sounds like it given the conditions... 3rd gear, going up a hill... engine under load.

 

I wouldn't really call it pinging - it sounds a bit like cards stuck in the spokes of a bicycle as its wheel turns. Of course the sound has a much higher frequency since the engine and/or wheels and/or transmission are spinning much faster.

 

Bumpers!!!

 

Like UMD said Sounds like pinging/engine knock, just because you say it happens under load.

 

I won't say it's not pinging/engine knock because I've never had that before to know what it sounds like...but I Just don't see it being that. It feels perfect, and it's always in this particular RPM range (2500-low 3000s).

Speaking with my wife we now agree that it's the same sound our 93 sentra has done since we bought that car (at 140k and it's now at 170k). Also, the maxima has been doing this since we bought it at 37k. Thing is now it's a bit worse. I'm starting to wonder if it's the timing chain. It's always been a slight sound on the sentra...and I can't always replicate it on the maxima, but it's definitely the same sound. It's DEFINITELY coming from the right of the engine bay (perhaps even the wheel well).

I'm running out of powertrain in a hurry, but I just don't know if I can demonstrate it to a mechanic or know what they'd do about it. I'm going to jack it up and look for possible looseness underneath, but I think it may be something internal...

The car's power is still top-notch if that's any use.

 

slight spark knock should not cause power loss... that is why you find the car still as powerful

 

It's a seriously _rattling_ sound though. Again, I don't know what "knocking" would sound like but I presume it wouldn't sound like rattling would it...? I have a new set of plugs waiting to go in, but I have this exact same sound on the sentra, even after it had new plugs put in...

 

detonation/pinging/spark knock... best way to describe the sound would be to liken it to shaking up a tin can full of marbles...

 

Hmm...I'd originally have described my sound as a playing card against bicycle spokes, but I think I could describe it as what you mentioned. My wife thinks that a tin can full of marbles is a good approximation of our sound.

I was just reading my haynes and it listed one issue as "pinging/knocking while accelerating or going up hills". I'm really really hoping that that is what this sound is.

I appreciate your help a lot btw and any other ideas!

In regards to my next step, first thing tomorrow morning I'm going to change all the spark plugs. I picked up a set of OEMs from nissan on thursday (they are pre-spaced for my car, right?), so I'll stick them in and see if I can get this problem resolved that way. If I can it would be very much sweetness I will update this thread either way, so that somebody in the future may benefit from it!

 

Well I switched out all spark plugs yesterday with OEM plugs. One of the 6 was a bit worn, but otherwise they looked ok for the most part. The rattling sound is still here though I'll probably jack the car up tonight, though I don't know if I'll be able to see anything or not...

 

Have you been using premium gas? Premium gas will help get rid of knocking. If you have then I don't know what to tell you...

 

Yeah I'm big on premium gas, and most of it around here is 93. I'm really thinking it must be something to do with a loose piece of metal somewhere, and when the engine moves (as they tend to do when you give them throttle) it's freeing up the room that lets this piece of metal loose, then that combined with wind and RPM is letting it rattle. It's really a bastardly little thing

 

*UPDATE* The nissan dealer said that he was able to replicate the problem and said that it was valve tapping caused by faulty ignition coils. The ICs on the 2000 max have been known to go bad and there is a TSB out for them (I never had a chance to get it done a while back). Replacement cost is 6 X $70/piece (even I can do the labor, which somehow they claim would take them 2 hours, but I could do it in like 30 minutes or less!). However, he claims that if I leave this, it won't cause damage (it is slowly getting more frequent). I don't like the idea of valves tapping - and sometimes it's pretty loud - but if indeed it won't cause problems, then I have no problem with saving $400 and having it rattle every once in a while.

Any ideas on his claim that it won't get worse?

Also I had them change out my oil pressure sending unit and it was covered under powertrain (59,200 on the odo haha!).

 

If there's a 60k powertrain and a TSB, why does the dealer want you to pay?

 

Powertrain doesn't cover coils according to this dealer, and another one I called.

 

I would call Nissan and double check. It seems like they're part of the engine to me.