nate_88

Just as the title asks, where do the typical boost leaks take place? I would assume they would take place in the rubber boots and possibly the wastegate, but would they occur anywhere else? My acceleration dropped off a noticeable amount, I'm laying down smoke like crazy even with light throttle, and the turbo doesn't build boost as fast and doesn't build as much (lost about 5 psi). I could hear the leak from inside the cab as I was driving over here, and it sounds like there's some sort of air leak coming from the passenger side when the truck shuts off as well, and it's not the air box. I'm living in Salt Lake City for 2 months away from home, so I don't have access to any tools really, except for a socket set and screwdrivers. If I have to, I'll go to an auto parts store and buy the parts I need. How could I go about finding the leak?

JohnX

Check all the boot around the turbo, to the intercooler, from the intercooler. Check the boost signal line to your gauge. Check the Intercooler itself. Check the gasket around the air horn. Check the wastegate boost signal line and the AFC boost signal line.

Boost leak can occur anywhere there is boost.

winkdemon

cooler boots , intake gasket, intercooler , loose clamps , bad turbo, you using any oil ? all of this stuff i have had to fix more then one time on my trucks ,
hope that helps

nate_88

Should I just pull all the boots off and check each one? I'm not sure where the AFC is on these trucks or what they are. When it comes to the gasket around the intake horn, or anywhere that boost runs for that matter, would soapy water and letting it idle to find where it bubbles work? Sorry for all of the questions, just trying to get my acceleration back . Thanks for the help guys

JohnX

No AFC on a 24 valve, sorry.

Try the soapy water and look for bubbles....but a stethoscope works better. These trucks are pretty load, but if you can hear the air leak from in the cab, you should be able to find it by sound.

JohnX

Oh yeah...I wouldn't remove the boots unless you find a problem.

Tate

Soapy water on a idling truck will only find a real big leak. There is no boost at idle, so if a leak doesn't occur till 5 psi, you won't find the leak. Don't forget to check the elbow off the compressor housing. It is a v-band flange with an o-ring inside. That can also go bad. The intake gasket under the fuel lines is a commonly overlooked leak point. There have been occasions when people install an aftermarket lift pump/filter setup, the remove the old stock filter, and don't put the screws back in the head and tighten them all the way. The gasket will blow out right there. Same goes for the bolts that hold the fuel line clamps to the head. All the bolts closest to the valve cover are through holes into the intake, another leak point.

JasonblkZ06

You wont be able to hear anything with the truck running. Buy a fernco plumbing coupler that matches your turbo inlet size at HD or Lowes and a pvc pipe cap and clamp that in the coupler. Before that - take the cap and drill and tap for 1/8npt hose barb fitting and screw that fitting into the cap. then use an air compressor to hook up to and pressurize the intake system to about what boost levels you run. Keep pressing the air gun lever as you listen and find all of the leaks. There will be more than 1 and start with the biggest ones first so you can hear the next size down better after the larger ones are fixed.

JohnX

Sounds like a nice idea, but if valves are on overlap you won't be able to get much pressure I would think. Have you done it this way to look for leaks? Did your compressor have any trouble keeping up?

That really is a great idea.

Homestead

A few minutes and a few bucks at Home Depot will build you one of these pictured below. You'll find your leak real quick. I added a few things like the air hose and a pressure guage because I had them but they are not needed. Just charge it up and look/listen for a leak.

Jeff

Tate

Back off any intake valves that are not loose before doing it. Since the valve cover will be off, you be more likely to hear if air is hissing past a valve seal.

graphitecumnz

a real popular place to find a bad boot is the lower boot on the inlet (passenger) side of the intercooler... that boot is dangerously close to the inner fender and has been known to develop a tear... a hammer can be used to massage the fender out of the way.

ldornak

Mine was on the drivers side lower boot. I used pliers in place of a hammer. The metal was easy to bend out of the way.

ldornak

I could never find the correct size fernco at HD or Lowes. They were either way too big or too small.

nate_88

How do I back off the intake valves? I haven't messed with those before so I'm not too sure how to do it.