Intercooler plumbing air leaks

[c5dura]

While I was at the dealer yesterday to take care of a few warranty items, I took one of the techs for a drive with me to demonstrate the whistling noise my duramax makes during hard acceleration.

He immediately suspected the connectors on the blue intercooler hoses. So we pulled into a bay and him and the other duramax tech repositioned all the hoses and made sure all the clamps were nice and tight (I think there are a total of 8).

So we went for another drive (basically another 1/8 mile run on the dealer parking lot in between all the new cars :D , and the noise appeared to be gone. So I leave the dealership and head back to work thinking I finally got rid of that noise. Just to make sure, as I go over the Blue Ridge Mountains, I turn off the A/C and radio, and got WOT and soon hit 96 and hold that for a minute or two.

Well, there is still a small air-leak in the system somewhere as the same noise is still there, although much less pronounced than before.

I'm thinking I'll pull all the blue hoses off and clean the contact surfaces on the blue hoses and the aluminum pieces and put everything back together again.

Has anyone else had this problem and is there some type of sealant you can use to ensure a tight seal? (any sealant would have to be flexible enough to allow removing the hoses at a later date for service, etc)

[hoot]

Turbo chargers make high pitched whines.

The turbine wheel spin in excess of 100,000 rpms at times.

Ever notice the singing a big rig does next to you on the highway? That's the turbo.

What you are asking is like a jet pilot telling the mechanic the engines whine.

You will never get rid of all of the the high pitched noise unles you remove the turbocharger.

[c5dura]

The noise I'm talking about isn't coming from the turbo. I'm quite familiar with that noise and I actually like it and can control the pitch of it with the gas pedal. Yep, I hear the same thing on big rigs all the time (although they are much louder than my turbo, although back when I ran the K&N Aircharger, mine was pretty loud as well).

This is a different whistle like noise that doesn't change in pitch the same way the turbo does. Prior to my ditch incident, and subsequent flushing of my intercooler, I never had this second whistle noise. It only began after all the intercooler plumbing was removed and re-installed.

C5dura

[Kennedy]

Check, but do not overtorque the clamp on the center section of the turbo. This can make some odd "rushing" noises.

Remember, you are holding back a nearly equal, and sometimes greater amount of exhaust psi as well.

Before you ask the TQ spec, I'll say "just about that tight" so if you find a spec, please share.

[ 07-15-2003, 07:59 AM: Message edited by: kennedy ]

[hoot]

If it's not the hoses you could have a crack in the intercooler.