Ford Mustang Forum banner

1 - 12 of 12 Posts

·
Registered
Joined
·
13 Posts
Discussion Starter #1
Hey everyone,

I have inherited the care of a 1999 4.6l gt (150,000). It runs great, lots of power, and no oil leaks. Its my girlfriends car and she drives it very soft. For the past few months we have been hearing a chirping sound from the engine at idle when it is warm (about 15 min of driving). I have stuck my ear everywhere and I am positive it is coming from underneath the throttle body (slightly to the front and to the passenger side). Just to make sure I applied the old soap to the belt trick and there is no change. I have an idea as to what it is, but I wanted some second opinions before I jump in. There have been no codes thrown as a result of this. Any insights would be.greatly appreciated.

I would consider myself an intermediate level mechanic. I can do more than change an alternator and spark plugs, but I am not going to open up an engine ;).

Thanks in advance for the help
 

·
Registered
Joined
·
804 Posts
Is it a rhythmic chirping? How frequent? Could you post a video?
 

·
Registered
Joined
·
491 Posts
Remove the belt completely and run it for a few min to see if the noise goes away. If it does then it could still be the belt and/or a pully. From what you describe it sounds like it might be the water pump.
 

·
Registered
Joined
·
1,575 Posts
Remove the belt completely and run it for a few min to see if the noise goes away. If it does then it could still be the belt and/or a pully. From what you describe it sounds like it might be the water pump.
Don't run it too long without the belt.. Your spark plugs will quickly drain the battery when the alternator doesn't make the power for them. Also, be careful not to overheat the engine. Run it a few minutes tops if you are going to take off the belt.

Another thought; could it be the tensioners/guides for the timing chain that causes it? Since the frequency is related to the speed of the engine.
 

·
Registered
Joined
·
13 Posts
Discussion Starter #6
Alright, I will run the car without the belt after my G-friend gets to her house tonight. I did not think of the water pump, although I am confident thats something I could do. It just seems like the noise is coming from farther back than the belt area.

Thanks for the advice, Ill post tonight to tell you all how it went.
 

·
Registered
Joined
·
5,329 Posts
The first thing that comes to mind is the chain tensioners/guides, but hopefully it will be more like a belt driven...
 

·
Registered
Joined
·
13 Posts
Discussion Starter #8
The first thing that comes to mind is the chain tensioners/guides, but hopefully it will be more like a belt driven...
I looked up problems with the timing chain online and the sounds are different. It is a high pitched screeching chirp... eek eek eek eek eek instead of a tapping sound that the videos had in them. It sounds like a belt noise but from under the throttle body... I know this is not much to go on, but there you go :)

Whata bout the Cam Sensor, could that cause something like this?

I will still check the belts and pulleys tonight.

Thanks
 

·
Registered
Joined
·
1,575 Posts
I looked up problems with the timing chain online and the sounds are different. It is a high pitched screeching chirp... eek eek eek eek eek instead of a tapping sound that the videos had in them. It sounds like a belt noise but from under the throttle body... I know this is not much to go on, but there you go :)

Whata bout the Cam Sensor, could that cause something like this?

I will still check the belts and pulleys tonight.

Thanks
Well, it seems really unlikely, but what if it is related to a spring or a valve? Maybe it's not getting a sufficient flow of oil and therefore makes metal-to-metal contact? It does sound a little absurd, lol. Just throwing things out there. :bigthumbsup
 

·
Registered
Joined
·
13 Posts
Discussion Starter #10
Again, thanks for the suggestions. I was not able to.check it out tonight becausee when mtg friend came over there was no noise. I guess I should have mentioned that it is intermittent huh :). I am going to take her car this weekend and carry a half inch wrench with me. when it starts Ill pull over and test it.

I don't think this has anything to do with it bit full disclosure: last week I replaced the intake manifold (the plastic thermostat housing or whatever you want to call it was cracked and leaking). When I did it I also replaced all the plugs, cleaned the coils, and changed the air filter. It was making the sound before this, but now it it easier to hear (the engine runs smoother now though so I chalk it up to beojg able to hear it better instead of other bbeing louder). Anyway, Ill past the results when I get to remove the belt.:bigthumbsup
 

·
Registered
Joined
·
5,329 Posts
What weight oil are you running? A problem with the cam pedestals could cause such a noise, at least in theory. Or a vacuum leak, even a bad motor mount might.
 

·
Registered
Joined
·
13 Posts
Discussion Starter #12
Hey everyone. Thanks for all of the advice. I removed the belt and ran the engine and the chirping was still there. So, I began thinking about the lifters and perhaps not getting enough oil as was suggested. Well, I didn't want to remove the headers so I added some Lucas oil stabilizer and it stopped almost instantly.

Here's the thing. I know the Lucas oil treatment has mixed reviews because it could foam and cchanges the viscosity of the oil. What I am going to do is run it to the end of this oil change about 1200 miles, and then see if it makes a noise with only regular oil we use high mileage synthetic, whatever the engine calls for).

Any comments of experiences with Lucas products?
 
1 - 12 of 12 Posts
Top