[bandhog]

I have had engine noise for a little over a week now. The funny thing is the engine noise is there only after the engin gets warmed up. Its a light ticking noise and does not get any louder if I'm in gear. On restart after the engine is warm, there is a different noise starting up...Anyone had similar problems with their MO?

I had the dealer checked it and I'm taking it back in on Tuesday to have work done to it...hopefully it gets resolved.

 

[Trev]

Tough diagnosing a noise. Does the ticking increase as you rev the engine in neutral ?(possible valve, top end issue).

What does the second noise sound like on start up?

 

[Gonzo]

Noise fuel injector?

 

[bandhog]

noise does not increase when I rev the engine..and the noise is more noticeable inside the car. maybe coming from somewhere near the walls of the engine compartment but I don't know..Taking my Mo in sometime this week to have them replace parts that Nissan thing is causing the problem.

 

[photog]

i had a similar problem, had it in a few times to be fixed. found out it was something with the fuel rails under the car, they were apparently vibrating. also, had the fuel pump replaced. problem solved. noise sounded like it was coming from engine, but this is what it was.

 

[bandhog]

That was it. The fuel line was vibrating. the dealer replaced the damper on both fuel pumps and a seal. Noise is gone. My dealer got it right the first time.

They told me they replaced both fuel pumps also but I don't see that on the service invoice, so I doubt they did.

 

[GripperDon]

Didn't even know we had two fuel pumps. I know of the turbine type pump in the tank, Where is the other one.

I also know we have electronically controlled Engine Mounts with a "Hard" and "Soft" Condition Depending upon if engine is at idle or not.

But this is the first I have heard about the two pumps, Neato!

 

[bandhog]

My service consultant said one on each side.

But it was interesting to hear that we got two fuel pumps on the MO.

 

[GripperDon]

I checked the service manual and it shows a main and a sub level fuel level sensors but only one fuel pump a single supply line and a single evap return line. Maybe the dealer saw the two line and thinks thay are both supply, either that or has as TOO much fuel himself.

 

[Eric L.]

Grip is right. I think your dealer inhaled too many gasoline fumes. My FSM also shows just one fuel pump. Its possible the actual fuel pump comes in two separate assemblies, hence two parts.

 

[Gonzo]

Didn't even know we had two fuel pumps. I know of the turbine type pump in the tank, Where is the other one.

I also know we have electronically controlled Engine Mounts with a "Hard" and "Soft" Condition Depending upon if engine is at idle or not.

But this is the first I have heard about the two pumps, Neato!

How do those things work anyhow?

 

[GripperDon]

Engine Mounts (4 mounts per vehicle)
1 Electronically Controlled Liquid Filled, 3 Static

Basically the solonid control valve is connect via the engine CPU to determine RPM etc. This determines if it should open or close the valve to allow the fluid on the front engine mount to flow back and forth from the main to the supplemental chamber. Thereby making this mount "Softer" or closed "Harder".

You only actually have to regulate the one in the front to effect the whole stems ability to allow more of less engine rock or said another way transmit force pulses into the vehicle structure.

Here is anothers description of a systme "similar" to ours:


Basically it's a hydraulic mount that has two chambers filled with fluid. A large orifice valve and a small orifice valve connect the chambers. The large orifice is a rotary valve while the small orifice is always open. The small orifice makes the mount work like a stiff shock absorber.

When the engine is idling, a vacuum motor turns the large orifice valve to the open position. This allows more fluid to move between the two chambers. This makes the mount softer and absorbs engine idle shake. The Powertrain Control Module (PCM) controls when vacuum is applied to the large orifice valve through a solenoid valve.

Above idle speed, vacuum to the large orifice valve is vented and closes. It goes back to the small orifice operation and becomes stiffer. To check it, apply vacuum to the engine mount with a hand vacuum pump and note the reading. It should remain steady. If it drops the engine mount is bad and needs replacing

 

[Gonzo]

Thanks