Exhaust leak? Turbo Sound?

[knkreb]

Since I now have a truck chassis... this is a whole different deal than the van (bus) from before. The sound of the engine is very different in the cab vs having just a dog house to dampen the noise.

The wastegate was not operational at first, but now I have it locked shut for the moment. I don't have a boost gauge or anything else to verify operation... but I don't *think* I'm building a whole lota boost.

There seems to be sound, almost like an exhaust leak maybe somewhere in the system. Anyone have a quick fire way of pin pointing that? Engine running seems to drown out any small leaky noises. I was thinking of using a shop vac blowing up the tail pipe to see if I could hear anything under hood.....

Clue number two is, with the wastegate locked shut, I went WOT, and never threw a code for over boost.

Clue number three is subjective of course... Is the turbo very noticeable in it's sound in the cab? I could very clearly hear the turbo in bus 1 with it only 12" away from my right foot. But this has that plastic tube thingy projecting out from the turbo inlet, etc.

Bus 1 had a soot trap that was "opened up" for full flow. This also greatly improved the turbo sound.

I noticed the difference tonight as opposed to the first test drive... less smoke on WOT. I had a little blast at the beginning, and shifting. The first test drive was a bit lethargic, and quite a bit of hazy black smoke (not belching of clouds).

So, am I just getting deaf on the turbo sound, and how to check for a leak?

 

[Acesneights1]

The plastic thingy is a sound deadener for the turbo whistle. a 1 3/4 rubber freeze plug eliminates it nicely IIRC. It will sound different than your van because the Vans have a center mount turbo. As far as looking for ex leaks the two best ways are first get a good drop light and look around for black soot. It could be a manifold to head leak. If that reveals nothing wait till the truck is good and cold(overnight, colder the better) and have someone start it and race it up a little right away. when it's blowing a little raw the leaks can be seen better other wise just look for the usual spots. Crossover donuts,DP to manifold, manifold to heads. When you say it didn't code while you had the wastegate held shut, was that in neutral or was that driving down the road ? It will not build enough boost dry revving it but if you wire it shut it will build boost very fast and defuel under load. when I tested mine I never got a code but I did defuel so you may not see a code. Best to put a gauge on it especially if you are going the TM route. Boost gauges are cheap Even my Autometer pro series was under 80$ and that is the best money can buy.

 

[knkreb]

Ah yes... boost gauge... like I was telling my kids tonight when they were complaining about their little reading lights not working in the back seat... "We've only had it for 72hours, can I get a chance to work on it?"

That rough test of boost was under load. And I shouldn't say it didn't "code"... I didn't have defuel OR an SES light... so it tells me we are not tipping the scales yet to overboosting. The puppy chewed up my cable for the code reader... so I'm flyin' blind at the moment.

The bus would do both rather quickly in an overboost situation.