Daniel B. or anyone who knows how to fix my problem. The other day I was looking under my hood and I heard a ticking sound. My keys were in the ignition but the car was not running.(the engine was cold) Does anyone have any idea what this might be? Thanks for your help in advance!

-MDM

 

Was it a regular ticking, or irregular? Car/engine cooling down?

 

WAY to vague. Was it the only one time or did it do it continuously? Was it from any particculaer part of the engine. What were you doing? Does the car run okay? You need to fill in the holes.

 

It is important to identify the source of the noise. A four-foot length of small diameter rubber vacuum hose will help you do this. You can buy the hose in any auto parts store. They typically sell it in bulk for about US$0.80 per foot. Put one end of the hose in your ear and the other end near any suspected source of noise. The benefit of the hose is that it isolates the sound from one specific area.

When you have more specific information about the source of this suspicious sound post it on this thread.

 

Daniel, I'll go buy some hose tomorrow and try to pinpoint the noise. I checked on it earlier (engine cool for 5 hours), whenever I put the key in the ignition and turn it to acc, a "ticking" sound is heard somewhere near the center of the car behind the engine block. I'll be more specific tomorrow.

-MDM

 

Are you sure it isn't the fuel pump?

 

This sound is unlikely to be the fuel pump becuase ...

- The fuel pump makes a whirring sound, not a ticking sound.
- The fuel pump is located inside the fuel tank. The sound it makes is more noticeable at the rear of the car than under the hood.
- The fuel pump does not run with the ignition off. With the ignition on but the engine off the fuel pump runs about four seconds and turns off.

 

I agree, but at the end, I always hear a clicking/ticking sound as it shuts off.

True, but you can hear it all around the car. He said, Behind the engine block.

He never specified the length of the noise.


I'm just throwing possiblities out. Hell, it could be anything, from noisy pre-cats to a loose electircal connection.

 

Yes, that is right. Please don't take it as a personal affront if someone disagrees with you. We are all trying to help Max96LSU. It will be instructive for all of us to learn the origin of his mysterious sound. The great strength and value of this forum is how we learn from each other.

 

I'm not, sorry if it appeared that way.

 

Here goes nothing....
I did what you said to do DBM with the hose. I'm not too sure where it's coming from but I pinpointed it down to 2 locations.(yellow circles) The picture I'm using is not of my hood, but it's similar. I don't have the K&N cone.

 

Here goes nothing....
I did what you said to do DBM with the hose. I'm not too sure where it's coming from but I pinpointed it down to 2 locations.(yellow circles) The picture I'm using is not of my hood, but it's similar. I don't have the K&N cone.
So what do you assume it may be?

 

The larger oval, the one nearer to the windshield, looks like the ASCD actuator. ASCD = Automatic Speed Control Device. That's the Nissan name for Cruise Control. There is a good photo of the ASCD actuator in the Haynes repair manual, page 12-16. Haynes calls it a cruise control servo.

The smaller oval looks like the Throttle Position Sensor. There is a good photo of the TPS in the Haynes repair manual, page 6-9.

I tried to recreate your Key On, Engine Off situation but did not hear any clicking under my hood.

You could pull the ASCD fuse temporarily. That's fuse #12, 7.5 amps, in the passenger cabin fuse block. Then listen for the clicking sound. If not heard, that would point toward the ASCD.

One component in the ASCD is an electric motor driven vacuum pump. This part is perfectly silent on my Maxima. However, on the Stanza I formerly owned this pump always made strange sounds as soon as the key was turned on. The ASCD always worked well, so I accepted the strange sounds as normal. Not desirable, but normal.

 

A POLTERGIEST !!!

hehehe, on a serious note though, i think this throttle adjustment is controlled by a small electric motor or atleast it sounds like on, if it's ticking it may be a stripped tooth.