I recently did an EGR cleaning on my totally stock '08. Now I feel that I'm hearing a whistling noise...goes along with the rpm increase as I gradually accelerate. It sounds much like a big truck's turbo, or like some of the played-with kid's trucks (especially Powerstrokes) that I hear running around town. I can't say for sure that I didn't have the sound before. Maybe I did and just wasn't tuned into it. I've gone over every hose/pipe/etc. joint that I had apart during the EGR cleaning and they're all tight. I had a leak at the rear of the EGR cooler once before. That made a squealing sound when the engine brake was working...this is nothing like that was. The truck runs great, although the fuel mileage sucks. I never did see this 2 mpg increase that everyone says happens at break in after 15k-50k miles. My best mileage was when the truck had 10k on it...

Any ideas on what I might be hearing? Or if it really means anything? There weren't inter-cooler cgrack issues on the '08's were there? If so, how would I get the dealer to check it?

 

You can check for boost leaks quite easily by using a 4" ( if I remember correctly) PVC cap and secure it into the rubber inlet hose on the front of the turbo with the factory hose clamp. I drilled and tapped a 1/4" NPT thread and stuck a quick connect and gauge in the cap. Hook up an air compressor, fill it to a reasonable pressure, 20 psi maybe, and watch for the pressure to bleed down. Assuming your engine isn't losing compression from bad rings or valves, you should see a steady pressure that doesn't drop off over time. If the pressure drops you probably have a leak in your piping, after cooler, or worn engine parts.

 

Since the squealing started after you had the EGR off I'm wondering if the problem could be the gaskets that go between the EGR and its mounting. I always keep a new set in the truck just in case.

 

Thanks for the idea! I'll give that a shot over Christmas shutdown. The truck only has 60k on it, so I'm hoping that wear isn't an issue.

 

If you hear air leaking out of your exhaust don't panic, I just rethought the process. There's a good chance you will have some leakage as some of the intake valves will be open during the test, I seem to recall barring the engine over to the point of minimum loss and a spray bottle of soapy water to find the leaks did a nice job. Good luck!

 

My truck does the same thing, I can hear that same type of noise when I accelerate. Sounds like turbo whistle to me, Ive checked everything also and cant find a leak, at least in the intake part of it.