Boost while in Park/Neutral?

[DieselViking]

This may be a dumb question, in fact it may be a "Duh, you're a moron type thing", but I'm learning new things about these turbo-diesels everyday since I grew up around gassers, and I've always believed it's better to ask questions even if you feel stupid. Haha.
In my quest to find my vibration problem, my brother and I found that while in either park or neutral, if you rev my truck you get around 10-15 psi on the boost gauge, and you can see my intercooler boots expanding and contracting noticeably. Is this normal? I thought it was only normal to build boost while in Drive, under load? It's easy to make it read 10 psi when you rev it, if you really rev the t*ts off it to like 4000 I had it spike 15 and almost 20. I was thinking maybe my idle vibration problem had something to do with the VGT. On my stepdad's '04, the intercooler boots barely move when you rev it. On mine it builds boost and you can see the boots expand noticeably.

Otherwise, aside from the idle vibration and 1500 rpm moan, the truck runs normal.

Is this normal?

[cchase]

well the boots i dunno for sure but they are rubber for a reason i suspect... and heck yeah you can build boost while you rev it, the engine runs the same it just doesnt goo, hold the brake build boost then when its high let go, you'll have some fun. but building boost in N or P is normal.

[DieselViking]

Really? I read a couple other threads where guys were saying that when they rev it, no matter how high in neutral or park it won't build anything, maybe 3-5 at the most? Hmm.

[forddieseltweek]

I cant build boost unless Im driving it....

[cchase]

hmm, I could be talking out of my a** but i swear I could, or my gauge is going haywire.

[heloman27]

That is strange, if I rev mine it does not boost without load, in park it does not boost.

[goodriddance]

mine doesn't build boost in neutral/park, gotta have it under a load

[AFBLUE]

It sounds to me like an over active wastegate. Does the truck ever overboost when you are on it really hard driving? Like a steep section of the highway? I am just guessing but it sounds like the wastegate is stuck closed. I wouldnt know what its really supposed to do because my 95 7.3 doesnt have a wastegate.

[goodriddance]

Originally Posted by afbluesv1k

It sounds to me like an over active wastegate. Does the truck ever overboost when you are on it really hard driving? Like a steep section of the highway? I am just guessing but it sounds like the wastegate is stuck closed. I wouldnt know what its really supposed to do because my 95 7.3 doesnt have a wastegate.

the 6.0's don't have waste gates

[DieselViking]

Hmm. No conclusive answers? So what is normal? Zero psi revving in park or neutral w/o load? Or some boost? If it's boosting with no load does that mean the VGT is sticking? I could swear when I first bought my truck it didn't build any boost in park or neutral, even when I revved to 4100 rpm?