Engine noise has increased?

At idle my truck makes a scratching noises at acceleration it goes to a tapping noises I have no ideal were it is coming from it sounds like it could be coming from the engine

There was no change in the noise but it dose sound like it could be coming from the passenger side or underneath the engine

This problem just started on my way to work it is a squealing noise under the hood that also sounds like it is coming through the defrost vents on the top of the dash but I can also hear it outside. Any suggestions?

Thanks for your time

Thank-you very much for letting me know, hopefully I can figure it out!

Noises problem
1999 Chevy Silverado V8 Two Wheel Drive Automatic

Kind of sounds like the noise could be a fan blade knocking, but I checked while the engine was off and fan was not touching anything. What else could this be?

I recently had to fill my radiator and overflow tank, I was leaking water but couldnt find the source. It hasnt leaked for a few days, but levels are holding fine after only filling it that one time. The only other work done on it was replaceing the AC system over a year ago. Just today a humming noise started in front by the fan belt. At just an Idle, its and while driving it sounds like humming that gets louder then softer. Water levels remain the same, no signs of leaking. Any suggestions?

Have you checked the belt tensioner to make sure it is not going bad? Could be that or a bearing in the idler or alt. Or water pump. Could be the fan clutch. Just a few things you could check. Another possibility could be the transmission. They start to "hum" when low on fluid and change pitch with RPM's sometimes sounds like it is coming from the front of the engine. Good luck.

1997 chevy truck with 350. It is 6 degrees outside, I started mty truck for the first time since yesterday. When it first starts, there is an errr noise for about 1 second then it doesn't do it until I go to start up the next day. Any ideas?

So I have a 1994 Chevy K1500 that has been a great truck but is now having some issues that worry me. It recently got cold here in Nevada and since then my truck has been idling really rough and has lost a good bit of power. Along with that it now ticks really loud when under a load. It does it around 40-50mph at about 2,000 rpm but never when in park or neutral no matter how much I rev it. I just did an oil change on it and followed my mechanics advice on using a heavier weight oil (10W-30) as opposed to the usual 5W-30 that the oil cap says. I thought it was the valves ticking but everything I've read suggests that if that was the cause it would be constant and not just when I'm driving. The pattern seems to stay exactly in line with the rpms though so I'm at a loss. Anybody have an idea of what it could be and how much it's going to cost? Thank you.

Thank you. I'll try that and see what they look like. Could it possibly be the spark plugs? I pulled one just a little while ago and they looked pretty black.

I replaced the plugs, wires, distributor cap and rotor. Also, did an oil change with a new filter and now it's gotten worse. I've had a dramatic loss in oil pressure while driving and idling. So I parked it and haven't driven since. But when I first started the truck the oil pressure is at about 50-60 psi, then once I started driving and it warmed up it dropped down to about 10-15 when idling and sat at about 30 while driving. The ticking was still no where to be found in park or neutral and still only did it at around 2,000 rpm. The truck runs really rough now too. It feels like it's bogged down idling and wants to die and accelerates very slowly and cruises rough as well. I've pretty much exhausted my abilities as an amateur and I'm sure it's something internal at this point due to the change in oil pressure. It's also puffing little bits of blue smoke out of the exhaust when it idles. Thank you for all your help this far also. Any other advice would be much appreciated.