Boost Leak

[nboeger4]

I have been going back and forth with dp and I have concluded that I have to have a boost leak somewhere. Here is how the truck is running.

70mph 1000 degrees 6psi 2000rmp 80hp eco

65mph 1200 degrees 14psi WOT 80hp eco

75mph 900 degrees 5psi 2100rpm 80hp eco

75mph 900 degrees 5psi 2100rpm 80hp tow

Its running on the hot side and not putting out much boost. When I watch my boost it stays pretty steady. So what do you guys think it is? Is it a boost leak? Or a weak turbo that needs to be rebuilt? I'm not really sure on this matter. Let me know a good place for parts or rebuilds if that's what you guys think it is. Thanks

[mcbadwish]

I would check the wastgate then start checkin for boost leaks

[nboeger4]

What's the best way to check the wastegate?

[mcbadwish]

I havent done A 7.3 but the cummins and detroits I work on I unbolt the diaphram can and pull it push it and make sure there is a nice metalic clack when it closes.

[audiocontr]

Do you hear a wooshing sound under boost? like air is escaping? Take off your intercooler boots, clean them and put them back on. Simple and effective to trouble shoot. Loosen and twist the boots under the spider, then tighten again. Check your boost levels

Honestly, its your up pipes though. Replace them.

[nboeger4]

^^^No I can't hear any woosh sound either. But the truck is so loud as you all know its kinda hard to hear.


well i unplugged the red wastegate line today and was hitting 25 psi of boost at WOT...???

i looked under the truck with a horrible flash light and it kinda looked like there was black soot on the downpipe on the inside right next to the up pipe on the passenger side. and the drivers side looked kinda black. but im going to get under the truck tomorrow for more investigation.

Does anyone know the shop time on replacing the up pipes?? I'm thinking I might just have a shop do this one. Ive been real busy lately and I know those bolts arn't going to want to come out easy.

[audiocontr]

Hmmm. Sounds like your wastegate now. When your on the gas at about 50% throttle, does boost raise to around 20lbs almost instantly or do you really have to get on it to see 20+ psi? If it's the later, I vote up pipes.

Check the wastegate though as it's easier. Have to search the forum for more info.

The up pipes took me all day on Thursday. If I was to ever do it again, I would just cut the pipes and bolts out. You'll need a 3" cutting disk and a small sawzall. Replace with the bellowed pipes. I was able to do it with the exhaust in, easier with it out.

[nboeger4]

Just tested. 25mph about 2000 rpm. Hit it from 50 percent ish to WOT and it hit 20 plus psi pretty quick.

[audiocontr]

Sorry, I wasn't very clear. How about slight throttle to 50-60%? it should go from 0 to about 20 pretty quick. If it's around 10, but takes WOT in order to hit 20, it's the pipes.

[Dietoremain]

wow you have a big boost leak, i hit 1000-1100 pulling heavy on a grade on on my 80 tow tune.. can hit 1100 WOT on my 120r tune but ya...