Boost leak question?

[Lord Tauk]

Factory boost - sorry, no aftermarket gauges yet. I ditched whatever type of reuseable filter that was in there and went with Purolators drop in.

I'll take a look at all the clamps tomorrow. Sound has pretty much been there since I've had the truck, about two months.

 

[dpantazis]

keep in mind that the air is a COMPRESSIBLE fluid and whats in the COMPRESSOR wheel has to go SOMEWHERE when the pressure is taken off (GD pay attention in your fluids class!).

so if you are spooled up under load, and then the truck shifts, there is a drop in the RPM's. which means, that the compressor and impeller will slow down. whatever air is in the system already compressed will seek the path of least resitance. the motor is not taking the air in, and the air will rush out to fill the intercooler and the pipes. or something along these lines (brain freeze right now)

dennis

so at that point when the RPM's drop.

 

[Lord Tauk]

Good information.

However, that sound I'm hearing is not at shifts, it's WOT or close to WOT - when the boost builds up a good ways, just listen to the incab movie I made.

 

[Got Diesel]

I am am paying attention Dennis. Dont' worry. And here is what I got from his video, when he was approaching max boost, the pitch changed. This tells me that that something has happened. I think that this is the point when air starts to leak past whatever could be leaking.

And Lord Tauk you will not hear a boost leak just revving up the engine, because it only builds about 3psi maybe 4psi. However when watching that video listen to when you let off the throttle. The air escapes through the intake and you can hear that. With an open air element it is really pronounced.

 

[Lord Tauk]

Interesting enough though, my intercooler piping boots aren't oily at all. The pipes have alittle bit of slack in them, which I thought was normal, they appear to be tight.

The intake plenum to the manifold boots (orange ones) I haven't really looked real close at those, as stated, the clamps could be a little loose causing them to leak under more than a few pounds of boost? I hope they aren't too much of a pain to get to.

Sounds like the place to look then. Thanks for the help guys.

 

[CSIPSD]

Take a wrench to them and get them tight! Your leaking past one of them

 

[Lord Tauk]

Alright guys, an update. It was a leak, the drivers side plenum to manifold, the upper clamp wasn't even tight. Fresh oil spotted, I tightened her up and she's sounding like a turbo now. Thanks!

 

[Got Diesel]

Thought so, glad we could help.

 

[Crazy Cowboy]

Cool thread! I have the same issue on the Excursion I just got... driven a few lightly modded/chipped Powerstrokes before and never heard this air-leak (sounds like a punctured tire almost) sound before. Plus, when I get on the highway as it builds boost I hear the leak kinda sputter. No exhaust smoke, the truck's taken care of with oil changes and all so I am going to check out the couplers tomorrow!

Thanks guys, looks like this will be a new forum for me to hang out at A LOT

Dan
www.ExoticVette.com

 

[Got Diesel]

Welcome to SDD. It is a great place to hang out and learn a few things.