Hey y'all, just got finished with a new engine install in my truck. Runs and drives great (like a new truck)

But I've got a weird, random whistle that I can't identify. Have checked a lot of different culprits but can't identify it. Would love to hear thoughts from anyone who might know where to look next.

Attached a video to hear what it sounds like. It's a lot worse at startup and then barely noticeable when driving (practically non-existent when in gear).

 

Wow, that's weird. Does it sound like maybe a vacuum leak whistle? I can sure hear SOMETHING in the clip..... but, I have no clue what could possibly make that type of sound.... Metal on metal interference somewhere maybe??

 

Working with a mechanic friend of mine we checked all the vacuum lines and no leaks. Totally unique in terms of sounds...

I'm hoping that it's just something with the new engine that is working itself out, so hopefully with more then 7 miles on it it'll work itself out.

 

Try using a 3 foot section of garden hose to try and isolate where the noise is coming from. Stick one end to your ear, and move the other end around the engine. The noise will get louder as you get closer to the source. Just watch the hose doesn't get grabbed by something turning..... That's no fun.

 

Step 0 - with the engine COLD, remove the serp belt, and start it, letting it run no more than 10 seconds or so.

See if the sound's there then.

If it isn't, it's mechanical off the accessory drive; time to start spinning things.

If it IS, then time to start running vacuum lines and caps. (Could be a small split in a cap for that matter!)

I know your mechanic friend says it's not a vacuum leak, but it sure sounds like one!

RwP

 

How old is the fan and fan clutch? It doesn't quite sound like a fan, but I've heard some weird sounds from them. It's definitely rotational in origin. What about the water pump and alternator? Does turning the a/c on make any difference?