Weird Snapping Sounds

[EvanCole45]

Hello, my truck is an 88 2.9 5 speed and it started making a very weird snapping sound from the back of the engine bay about two weeks ago. After about 5 miles of driving the sound starts but goes away after a few minutes and two weeks ago it was pretty quiet but over time it's gotten louder. The sound hasn't caused any issues and it doesn't seem to effect anything whatsoever. The best way I can describe what it sounds like is slapping a ruler on a desk or a very high voltage electrical shortage. The snapping sound has a frequency of about 1 snap per second and the frequency does not change with engine RPM. It sounds like its coming from the heater box/ distributor area but I can't pin point the location. The most puzzling thing to me is the sound continues for about 10 seconds after the engine is turned off.

What could this possibly be?
Thanks in advance.

 

[Uncle Gump]

I would open the hood in a dark spot at night and fire it up and have a look.

I would also have a spray bottle with water to sprits things down a bit.

 

[EvanCole45]

I would open the hood in a dark spot at night and fire it up and have a look.

I would also have a spray bottle with water to sprits things down a bit.

I've tried that to see if I could see any electrical connections sparking and there was nothing.

 

[rusty ol ranger]

I had a 94 F250 with a 300 that would do that right before the AC clutch failed

 

[EvanCole45]

I had a 94 F250 with a 300 that would do that right before the AC clutch failed

I don’t think it’s that because the A/C is never used. The previous owner went and put hose clamps on all the A/C hoses so there is no Freon left in the system.

 

[Ranger850]

Might be a longshot, but here goes: Check your battery/charging system. My truck did something similar at one point a few years ago. I had just got home from work and as I'm walking away, I heard the sound you described. Turned out it was a bad battery and wasn't charging correctly. replaced that battery with a "WALMART" special for around $60.

 

[Uncle Gump]

I would also consider exhaust leaks... depending on temps they can get better or worse.

 

[Dirtman]

Your sure it's not the normal ticking/pinging noise of the exhaust system as it expands and contracts when heating up and cooling off? That's about the only noise that would continue to happen after the engine is shut off...

 

[EvanCole45]

Your sure it's not the normal ticking/pinging noise of the exhaust system as it expands and contracts when heating up and cooling off? That's about the only noise that would continue to happen after the engine is shut off...

It could be that because part of the exhaust was welded back in after I replaced the clutch a few weeks ago but this noise is very loud and definitely not a sound that a car should be making

 

[EvanCole45]

Might be a longshot, but here goes: Check your battery/charging system. My truck did something similar at one point a few years ago. I had just got home from work and as I'm walking away, I heard the sound you described. Turned out it was a bad battery and wasn't charging correctly. replaced that battery with a "WALMART" special for around $60.

Okay thanks. I’ll try that if I can’t figure anything else out.