[tofferr]

Hello. I am reading through the CVT and alternator threads now... but I'm not sure which one fits my problem more.

About 200 miles ago, I started hearing a noise that sounded a bit like engine knocking. It seemed most pronounced during acceleration. Transmission? Both the driver and the passenger thought it was coming from the opposite side of the engine compartment, so, it was probably coming from the middle.

Today, after getting a new tank of gas and car wash (after a 40 minute highway speed run) I started having more significant problems. When I pushed the accelerator, it wouldn't go unless I kept pushing and getting higher RPMs. This made pulling into the garage tricky (since I didn't want to launch through the back door).

What does this sound like to you? Anything I should look into at home before taking to the dealer?

Thanks,
Chris

 

[Eric L.]

Sounds like an electronic throttle control problem. Best take it to the dealer.

 

[GripperDon]

tofferr, What year is your MO?

 

[tofferr]

tofferr, What year is your MO?

2003, Purchased 11/2003. 16,000 miles. Just came out of a $200 checkup at about 15,500 miles.

 

[GripperDon]

Then I sure agree re. the throttle sensor.

 

[tofferr]

I took it to the dealer today. They said it was the throttle. They said a new one has been ordered, and they'll put it in when it comes in. This is covered under warranty.

They said they could not reproduce the "knocking" noise. I would also describe it as sounding a bit like a diesel engine. Oh well.

Thanks,
Chris

 

[Gonzo]

As we all know... one issue at a time with these Nissan dealers. They can't handle much more.

See what happens after the dealer replaces the throttle.

 

[GripperDon]

Have them check the knock detector.

 

[tofferr]

An update… the dealer had heard of problems with the Murano throttle and replaced that for free. After that work, the throttle was fine. However, the weird noise was still there. After a few weeks of driving on it, I have refined my description.

This noise is definitely related to the speed, rather than the RPMs – the frequency of the beat/pitch increases exactly with speed. It can be heard anywhere from <10 mph through 80 mph, though it is most pronounced between 35 and 50 mph. The oddest part (to me) is that it is much more noticeable during acceleration. It can be clearly noticeable accelerating through 50 mph, then if I come of the gas I can’t place it anymore.

This should help to place what component is causing this noise, no?

Also, in the last week I have started to have throttle problems again. It is not as big a problem as before – yet. Specifically, it lurches oddly. The most likely way to induce this lurch is to get up to highway speed… then come off the gas and coast for a bit. Say you coast down to 60 mph (from 80 mph)… when you press the accelerator just a bit (say to go up to 65 mph) this odd lurch happens. It also happened at least once when my foot was steady as can be on the pedal. This sounds like a throttle problem again, no?

Thanks,
Chris

 

[GripperDon]

Check this out


"The MO is in the shop to get a new tranny and guess what!?!

It was not the tranny at all after all. They're changing it anyway (it is my friend who is the mechanic).

The problem was coming from a parking brake bracket located just under the front of the AWD driveshaft. The cable was a little loose so the bracket was rubbing on the shaft making a tick tick noise because it was meeting the solder at every turn of the shaft.

What a mess for close to nothing. Close to nothing because the paint layer was already gone from the shaft and sooner or later either the parking break cable would have failed or there would have been vibrations coming from the worned & unbalanced driveshaft."

This noise is related to speed, not RPM MAYBE IT"S WHAT YOU HAVE. search the Tick-Tick noise.

 

[Trev]

Your description of it being noticeable only when accelerating sounds like the knock sensor isn't working properly. Are you running premium fuel?

I had this problem with a Ford and it took a few trips to the dealer to get sorted.

 

[tofferr]

Gripper, thanks... that could be it.

Trev, I agree the acceleration part sounds like knocking... but the noise is far to consistent (in my opinion) for it to be knocking. Also, it varies with MPH not RPM.

Thanks,
Chris

 

[tofferr]

My throttle problems returned again today. And the other speed related noise has been ever present. Luckily enough, I was near the dealer, with some extra time, when service was still open. I took a tech for a ride.

Contrary to anecdote my Mo faithfully reproduced for the tech all the problems she’d ever shown me. The highlights were extreme lurching at takeoff sometimes, and at other times an inability to pull away from a stop (if I was on a gentle incline, it might take 30-40 seconds for things to catch, and take off).

The tech decided that I needed a new Tranny. The service guy was nice enough to spring for a rental car – even though they normally don’t offer that.

Is there anything I need to know about a tranny replacement? I’ll keep you guys updated here.

Thanks,
Chris

 

[Dalite]

This is way off in left field, but.... Have they checked the "purity" of the DC coming from the alternator?

Based on my understanding of the "fly by wire" throttle system (and my understanding is limited), and the short lifespan of the replaced part that you have experienced.

Also coupled with the knocking noise being linked to speed. Could it be possible that the alternator is still putting out a pure enough signal to keep the ignition system going, but a dirty enough signal to keep it from running properly, thereby causing component failure and noise?

It still sounds like the trans replacement may be the best way to be sure, and I imagine they will do the necessary checks on the charging system before turning it back over to you....

 

[tofferr]

Interesting idea. Would tha be consistent with trouble accelerating from a stop, but not at other times?

Thanks,
Chris

 

[tofferr]

Here's my update...

On Jan 25 I dropped off my Mo with the above symptoms. On Feb 11 they had finished their extensive testing and started to install a new transmission and transmission control unit. They say that work will be done on about Feb 16. If that is true they'll have had the vehicle for 3 weeks and 1 day. They did pay for the rental (though I choose to pay $5 a day more for a better car (better in this case is a friggin Corolla)).

Does this seem normal to you? Should I make any demands of my dealer? I'm planning on just picking up the Mo and saying thank you... but I'm not sure if maybe this has taken so long that I might be entitled to something more.

BTW, the largest part of the extensive testing seems to have been this... Nissan Warranty wanted a pressure reading from a line leading to the Mo's transmission. My dealer tells me that in all other Nissans this pressure is supposed to be 150 psi... in my Mo it is supposed to be 750 psi... so he had to have a machine shop make a special part for them to make this reading. Once he had this reading then Nissan Warranty was willing to go ahead and swap out the tranny. Does this sound right to anyone?

Thanks,
Chris

 

[GripperDon]

Sounds reasonable to me. GRIP