Death Rattle or something else?

[mbrando1994]

I'm having a very faint rattle/chattering noise suspected to be around the left side of the engine more towards the back, but it could possible be in the front. Definitely more prominent on the left (passenger) side. It doesn't sound severe enough to be a timing chain, and it doesn't sound like the flex plate or TC problem many are noting. I first noticed a fast chattering upon hard accelerations where RPMs exceeded 3000. Once dropping down the chattering stops immediately. Now I noticed today while walking around my car while it was running I notice that faint chattering with it just sitting there. Definitely not as loud as it is at 3000 RPM but it's a distinct sort of chitter/chatter noise that has me worried. I have a bank 2 engine code for the catalytic converter system and that's it. That code has been there since I got the car and many mechanics have told me the only way to clear it is to replace with a genuine ford converter assy. which I think is over 1000? Not too worried about the code, but I'm wondering if it could be a header leak? Maybe something else? I don't have the money for a timing job so I'm hoping to god that's not it.

 

[Number4]

Put your engine size in your info, not the post, though that'd help too.

Assuming you have the 4.0?

Two things that make the noise, you already identified, one of which (timing) will cost you an engine. The 4.0's timing goes quick, don't drive much until you figure it out.

 

[mbrando1994]

Put your engine size in your info, not the post, though that'd help too.

Assuming you have the 4.0?

Two things that make the noise, you already identified, one of which (timing) will cost you an engine. The 4.0's timing goes quick, don't drive much until you figure it out.

Yes I have the 4.0 V6, I will fix that in my info. Here is a link so that you can hear the noise I'm describing. It is much more pronounced on camera than it is in real life. Only very faint, can't even hear it inside the cabin. After further investigation it appears to be coming more from the rear driver side and not the passenger side. I understand the rear chain is on the passenger side and goes down around the jackshaft? The fronts are on the driver side and in the middle but lower down? Could this be fixed by fiddling with or replacing the tensioners? What about the belt tensioner? It seems to be rattling around and moving more than I remember it with the engine running, could that be causing noise? Also, when adjusting the throttle from the engine bay, a slight puff of air can be heard right when the rpms go up, only lasts half a second, could a vacuum leak or something be causing this? It seems to be more pronounced on the drivers side for sure, sounds like it's coming from the area of the cylinders themselves and not the rear of the engine where the chain is

 

[Tech By Trade]

Sounds like regular valve chatter. Death rattle sounds more like a coffee can full of marbles.

 

[imp]

"Definitely more prominent on the left (passenger) side"

Really hard to diagnose if which side is unknown......PASSENGER is RIGHT SIDE.

 

[mbrando1994]

"Definitely more prominent on the left (passenger) side"

Really hard to diagnose if which side is unknown......PASSENGER is RIGHT SIDE.

My apologies. At first it sounded like the passenger side but is definitely louder right above the cylinders on the driver side. It gets louder at 2600 rpm and up but disappears completely when I let off the gas. This faint rattle can also be heard at idle. Not sure if they're related. Either way what can I do? Is it dangerous?

 

[mbrando1994]

Sounds like regular valve chatter. Death rattle sounds more like a coffee can full of marbles.

I'm getting a louder rattle at 2600 rpm and up but goes away entirely when I let off the gas. By regular you mean it's supposed to? I'm worried it's not safe to drive without spending thousands to fix it

 

[imp]

My apologies. At first it sounded like the passenger side but is definitely louder right above the cylinders on the driver side. It gets louder at 2600 rpm and up but disappears completely when I let off the gas. This faint rattle can also be heard at idle. Not sure if they're related. Either way what can I do? Is it dangerous?

@mbrando1994
Wish I could help, but have no field experience with these chain problems. All I can realistically do, is formulate ideas based on the theory involved. Sorry. imp

 

[icepickjazz]

Is the noise more pronounced when the engine is cold?

 

[mbrando1994]

Is the noise more pronounced when the engine is cold?

It seems to be pretty much constant throughout all running time. I picked myself up an auto stethescope today and proded around. The noise is actually loudest on the alternator and belt tensioner (4.0 v6), Some noise can be heard on the head on that side, but no where near as loud as on those two parts...could it just be as simple as replacing those two things? I'd hope. Or is it possible the notorious front chain is going and it's being transferred through those parts? How difficult is it for someone with moderate experience to replace the front chain? I think it can be done without pulling the engine

 

[imp]

It seems to be pretty much constant throughout all running time. I picked myself up an auto stethescope today and proded around. The noise is actually loudest on the alternator and belt tensioner (4.0 v6), Some noise can be heard on the head on that side, but no where near as loud as on those two parts...could it just be as simple as replacing those two things? I'd hope. Or is it possible the notorious front chain is going and it's being transferred through those parts? How difficult is it for someone with moderate experience to replace the front chain? I think it can be done without pulling the engine

@mbrando1994
In my own experience, use of a stethoscope has proven most beneficial. Once with rear axle noise, it saved going into the differential, ruled out noise there, confirmed it in wheel bearing.

In your case, I believe the point of loudest noise is likely the fault area. I cannot imagine chain noise being transmitted to accessory parts. Why not remove the drive belt, start the engine briefly, and see if the noise is then gone? imp

 

[mbrando1994]

@mbrando1994
In my own experience, use of a stethoscope has proven most beneficial. Once with rear axle noise, it saved going into the differential, ruled out noise there, confirmed it in wheel bearing.

In your case, I believe the point of loudest noise is likely the fault area. I cannot imagine chain noise being transmitted to accessory parts. Why not remove the drive belt, start the engine briefly, and see if the noise is then gone? imp

Now I may know a lot about cars but I'm not the best with engines, won't running the engine without the drive belt damage something?

 

[imp]

Now I may know a lot about cars but I'm not the best with engines, won't running the engine without the drive belt damage something?

@mbrando1994
You could answer that question with another. Suppose the God-damned drive belt BROKE as you were driving down the highway. Would that damage anything? Only if the engine overheated, (no water pump working), and you failed to heed whatever warnings were posted.

We use a variety of diagnostic techniques to try to "weed-through" the morass of possibilities responsible for whatever problem, failure, noise, vibration, mis-fire, shake, loss of power, etc., whatever the hell seems wrong, to try to arrive at an educated guess regarding the cause. One of those is starting the engine without it's drive belt operating, and observing results. imp

 

[mbrando1994]

@mbrando1994
You could answer that question with another. Suppose the God-damned drive belt BROKE as you were driving down the highway. Would that damage anything? Only if the engine overheated, (no water pump working), and you failed to heed whatever warnings were posted.

We use a variety of diagnostic techniques to try to "weed-through" the morass of possibilities responsible for whatever problem, failure, noise, vibration, mis-fire, shake, loss of power, etc., whatever the hell seems wrong, to try to arrive at an educated guess regarding the cause. One of those is starting the engine without it's drive belt operating, and observing results. imp

I see, thank you for the insight, I will definitely give that a quick go tomorrow, hopefully I'm just looking at an alt and a belt tensioner for now