Grinding Noise on Cold Start

[Mayor McCheese]

I'm trying to diagnose a grinding noise that I experience when I start my truck after it has been sitting for a while, usually overnight. This happens almost every time I start the truck, regardless of the ambient temperature. From searching around in these forums, I'm thinking it might either be a bad bearing in the water pump, or the starter solenoid isn't disengaging. There doesn't seem to be any impact on performance, and it doesn't happen after the truck has been running and I shut if off and start it again.

Here is a video of the noise. You can hear it right as I star the truck, and then it kicks in and out a couple times over the usual ticking noise (broken exhaust manifold bolt head... typical Hemi stuff...)

 

[NJMOPAR]

Loose heat shield on driver's side?
Try grabbing it on a cold start and see if the sound changes.

 

[Nick_rp]

I had a similar noise before and it was the exhaust clamp just after the cat. Only did it when cold. I imagine when it heated up, it closed the gap enough to keep it still

 

[ram1500rsm]

Yep sound like an exhaust leak. Get a long fuel hose and use it as a stethoscope. You should be able to pinpoint where the leak is fairly quick.
Good luck.

 

[Nick_rp]

Yep sound like an exhaust leak. Get a long fuel hose and use it as a stethoscope. You should be able to pinpoint where the leak is fairly quick.
Good luck.

This is the 2nd time ive heard use a fuel hose today. Never heard that before. Now i need to try it

 

[srv1]

Mechanics stethoscope at harbor freight for 5 bucks.I use mine alot,it works great.

 

[Mayor McCheese]

Thanks for the input guys! I tried holding the heat shield on the driver's side on start up, and checked the clamps around the cat, and neither seem to be the culprit. I'll have to try the stethoscope/fuel hose idea to see if I can pinpoint it. I had my tractor mechanic brother take a look, and he thinks it might be the starter solenoid. That's more of a pain to remove and bench test if that's the case though.

 

[NJMOPAR]

A starter hanging up from a bad solenoid would make a horrible grinding sound, not the rattling I hear. If you've ever tried starting a vehicle that's already running you know that sound.
Still think it's exhaust related. Solenoids don't unjam after warming up, they're either stuck or not.

 

[Nick_rp]

^ yea a grinding bendix has a very distinct sound and unmistakable. Its not the starter

 

[indept]

Definitely sounds like a bad bearing, alternator water pump, belt tensioner, belt idler pulley????