Fairly new to Diesels and especially turbos but have enough mechanic knowledge to come close to a problem. So I have a 2008 F-450, engine was replaced just before I bought it with a factory crate engine. It has 13,000 on it and is still under the 3 yr engine warranty.

Problem: When the boost starts, it make a sound like an air compressor leak and gets louder until about 10 psi boost and then starts to whistle. The whistling just gets louder and higher pitched as the boost goes up. It sounds like a fire truck if is vary the throttle. If I let off the throttle and let the boost drop below 10 then the whistle stops. If I gently accelerate I can keep it from whistling but still get the air leak sound. Any ideas? Do I take it to a dealer?

 

Check all your intercooler boots and clamps and make sure they are tight. Also check where the intake mounts on to the turbo and make sure all intake clamps are tight as well.

 

Also check for missing, broken exaust manifold bolts . Just had a 550 with a high pitch whistle . It was a broken manifold bolt .

 

You guys are awesome. Found the leak. It was the lower down pipe boot right in the front of the truck where it connects to the bottom of the intercooler. Now I just have to find a parts store that has one or go to the dealer in the morning.

Thank you for your help.

 

When you put new boot on make sure to clean where it mounts on intercooler and hot side pipe with brake cleaner to make sure there's no oil residue. Also when you put it together...spray some hair spray on parts that go together...it'll act as glue and help keep it from popping off under higher boost numbers.

 

Will do. I am about to drive to the dealer to get the part. Thank you for timely advise.

 

Update. Installed new boot, $65 from the dealer, and it drives quite (normal sound) and has power again. Towed the boat to the lake and all is well.