was climbing a steep grade on freeway towing around 9k trailer. od button was off. had truck in 60hp to mode. when i laid into it, turbo starting making a differnt noise. kinda a squealing noise off and on. it stopped when i eased off the pedal. do these turbos make noise under heavy load? thanks for reading.

 

I had that happen to me a few times before I figured out mine was. If you recently topped off your coolant, when you build heat from putting the juice to it - the degas cap squeals when it vents.

One other item - you have the loudest turbo with the loudest air intake, and that 6637 is no match for a 38R. I went with the S&B to get my boost and backpressure in balance. I haven't heard anything objectionable since upgrading my intake and leaving the coolant at a lower level.

 

I've heard of the belt squealing under load giving a high pitch squeal. Just a faint lil whistle.

 

Correct me if I'm wrong, but isn't the GT38R is the stock turbo, as opposed to the GTP38R being the ball bearing model? Does it sound like this?

EDIT: I see in your sig it lists the GTP38R. Is this problem with your truck, or is it a different one?

 

I think stock is GTP-38 and the ball bearing model is GTP-38R.

 

You're probably right. I can't keep those numbers straight, lol.

 

GTP38 is stock.

38R is ball bearing.

Stewart

 

Pikachu, did you ever find out what caused that noise? Mine makes the exact same noise on a stock turbo, other than that it doesn't whistle at the end, it is more of a throaty whine.

 

thanks for all the info. is the 6637 the wrong set up? i cant get enough of the turbo whistle.

 

Get an AFE... that'll do ya.

I think of it as 38Roller bearing.

That was some nasty surge up there... hard on the turbo.