81 210 engine bay noise

[Hawaiian620]

Weird sound started today. Gets louder if I give it gas. I've felt around and nothing seems loose and I haven't touched anything that silences the noise. Oil level is good, oil is a few months and less than 1k old. The sound is louder on the valve cover side than it is on the drivers side.

 

No lost of power, engine starts and idles fine.

 

 Below is the video I took. 

 

 https://youtu.be/ZhfLqhFtQ7I

Edited July 15, 2021 by Hawaiian620

[datzenmike]

Not hearing anything on the video. Rattle, tick, tap, knock, ping, ?????

[Hawaiian620]

10 minutes ago, datzenmike said:

Not hearing anything on the video. Rattle, tick, tap, knock, ping, ?????

 

Its the rapid rattle/flutter sound. Kinda like a card in bicycle spokes. 

[datzenmike]

Old ears my son. Can't hear anything like that.

 

So, gets louder?? OR speeds up when revved up? If it really gets louder then something to do with the exhaust as it definitely is louder under load.

 

Are the spark plugs in tight?

[Hawaiian620]

1 hour ago, datzenmike said:

Old ears my son. Can't hear anything like that.

 

So, gets louder?? OR speeds up when revved up? If it really gets louder then something to do with the exhaust as it definitely is louder under load.

 

Are the spark plugs in tight?

Spark plus are fine. After checking this morning, its gets more louder/faster when initially revved then goes away. 

 

From reading the forums and what Mike says, I'm leaning towards maybe a leak in the exhaust near the manifold. 

 

 

 

Edited July 15, 2021 by Hawaiian620
Updated info

[datzenmike]

 

 

What you can do is have someone start the engine when cold. Have your hands under the manifolds and ready to feel around quickly for puffs of exhaust. Practice on a cold engine so you are not fumbling around. You've got up to 10 seconds before the metal becomes warm.

[Hawaiian620]

Sounds good, ill try that this evening. Thanks again for the advice!

[datzenmike]

Back in the day a friend had a V6 Buick that made this whistling sound on cold start up, but quickly went away. I thought I could hear something but only burned my hands feeling around so I had him leave the car overnight. He fired it up cold and I found the leak squeezing our between head and block. Head gasket and intake gasket fixed it.

[Hawaiian620]

Odd noises are the worst. I guess over time someone learns what they all go to haha 

 

I had my wife start the car while I felt around the manifold. I couldn't feel anything or notice any change in sound. I drove it around and you can't hear the sound unless really listening for it. 

 

My plan is to use a score to listen to the valve cover. I just want to make sure its nothing serious. Thats my main concern. 

 

 

[afracer]

Open the valve cover and run it with it off to make sure there's nothing messed up in there. But it does sound like an exhaust leak.

[Hawaiian620]

On 7/17/2021 at 8:03 PM, afracer said:

Open the valve cover and run it with it off to make sure there's nothing messed up in there. But it does sound like an exhaust leak.

 

Will do. I'll be on a trip for a week, so I'll do it when I get back.  I need to replace the wheel bearings and front coilovers on the Titan too. That time of year I guess. 

[thisismatt]

Can't really tell from the video, but I would also guess exhaust 🤷‍♂️

 

What do you mean when you say it goes away after reving? Goes away completely or just at idle?

[Hawaiian620]

1 hour ago, thisismatt said:

Can't really tell from the video, but I would also guess exhaust 🤷‍♂️

 

What do you mean when you say it goes away after reving? Goes away completely or just at idle?

 

At idle you can hear it if you listen for it, when I rev up it gets louder, but at a certain RPM it seems to go away. 

[datzenmike]

I cranked my stereo, can't hear a thing other than normal engine sounds.

 

A rod is noticeable at idle but gets louder under load but softens and can disappear when you let off. Speeds up with the engine. A rod sounds like a sledge hammer on the side of the block. Will start as a very loud tap and progress to a loud knock. It never gets better and always gets worse. If you are careful you can drive if for months like that. Usually not. 

 

Valve clearance is a higher pitch ticking. Never gets louder and softer with load. Speeds up with the engine.

 

Exhaust leak gets louder under load and speeds up with the engine. Usually a bad gasket so it tends to get louder over time as it burns it away.