Hi all.  I'm running into an issue that's got me pretty frustrated, and I'm not making a ton of progress, but I've ruled a lot of stuff out.

 

Problem: 

 

My truck never boosts over 20-21 PSI (and I think it should given my mods), EGT's also seem SLIGHTLY higher than they should be.  Not noticing power issues though.

 

 

History: 

 

When I got the truck a bout a year ago, it only had upgraded (RV275) injectors.  It always boosted up to 19 psi and no more.  I added a Diablosport Power Puck (used), boost fooler (used), and boost elbow (new), and now I get around 20 psi (occasionally 21), and no more.

 

 

What I've done: 

 

- Discovered a cracked exhaust manifold, which I replaced with a 3 piece (no change)

- Got a Boost Tester Cap (http://www.siliconeintakes.com/intake-leak-pressure-tester/intake-pressure-tester-p-49.html), pumped up the system (several times) anywhere from 10psi to 25psi, soapy-sprayed down everything from the turbo, boots, pipes, intake, grid heater, plenum, boost gauge tube outlet on the horn, etc.  I did find a pretty major leak from a boot clamp that was loose and is now tight (no change), other than that everything seems tight and leak free.

- Noticed the gauge in my car was only reading like 6psi when pumped up with the test cap in place at the turbo inlet (compressor regulator was at 25psi).  Tested gauge, which tested good.

 

Other Things/Questions:

 

- My elbow's bleed orifice lets off a good bit of air when I pump up the system, but plugging it with my finger doesn't change much

- I think I'm at the point of suspecting that either I've forgotten something simple/done something wrong in my original testing OR have an issue in my turbo (some sort of wastegate problem?) OR maybe intercooler, which I doubt (manage to spray the bejesus out of it with soapy water and it seems to be holding fine). 

 

Any help would be appreciated.

Edited June 10, 201510 yr by Nates1999

Are you using a adjustable elbow? I've got one here that does not close enough to allow me to bulid boost over 20-22 PSI period. So to verify if the elbow is the cause I would disconnect the wastegate line and plug it. Then go for test drive and watch you boost pressure it might really climb now.

 

While pressurizing the system you should be able to see the wastegate movement.

Thanks!  I'll give that a shot this afternoon.  Yeah it's an adjustable elbow off a seller with lots of history and feedback on ebay.

HX35 or HY35 turbo? 

HX35 or HY35 turbo? 

It's a 99 so it has the hx35. (Plus you can't put a boost elbow in a hy)

 

I like Mike's idea with the plug and test.

HE'S got  A AUTO TK, HE'S A HY35 TURBO   He ant gonna get no more than that. I Crimped my metal line shut and still couldn't break 20psi with edge ez and 50+ DDP'S,, Thats all that 9" rump will handle

 

I DIDNT Know the 99"s had HX35  Thought all Autos had  HY35...MY Bad

Edited June 10, 201510 yr by rburks

i cut the metal line into and used flaring tool and managed to rig a HOMEMADE BOOST ELBO FROM A BRASS AIR TANK CUTOFF,  it actually worked pretty good

Yeah it's an hx35. Good news. Put a clamp on the line and now I get to 29 psi easy (and that was unloaded just ripping on it for one freeway on ramp) so it looks like an elbow issue. Egts are way down on the high end too.

Thanks.

I did notice that after 25psi my turbo sounded a little different than normal. Kind of a little (really little) shrieky. Is that normal?

DID YOU MEAN SCREELING SOUND..... THAT DONT SOUND GOOD....you need to pull your boot hose off Air side of turbo(one that goes to Air filter). check for excessive play from side to side in compressor wheel. if its making a noise you should see evidence of it rubbing the side of housing

if there much metal of course you know your turbo has to be replaced,.." but you'll also need to pipes loose from intercooler and clean flush intercooler and pipes before re-installing turbo. id would remove it if there is much metal shavings in the rubber boot at the neck of intercooler so you could flush it real good

could always make a J-hook like i did. it kept my 02 around 30 psi.

I'll get the elbow squared up.  May just be adjustment.  

 

Now I just noticed I've got a pretty good stream of dried coolant coming out of the head to block connection below the thermostat...  UGH!  Anyone have a set of studs they aren't using?  Guess I know what my next thread will be.

Sorry you'll have to replace the gasket. Studs will not fix a corrosive coolant damage gasket. Way too many people assume coolant will last forever and not need to be flushed.

I know... Just going to go ahead and do studs at the same time.

Studs are not required till boost pressures are exceeding 40-45 PSI. It won't prevent coolant damage on head gaskets. I currently touch 36-37 PSI on stock HX35 and no head studs.

HE'S got  A AUTO TK, HE'S A HY35 TURBO   He ant gonna get no more than that. I Crimped my metal line shut and still couldn't break 20psi with edge ez and 50+ DDP'S,, Thats all that 9" rump will handle

 

I DIDNT Know the 99"s had HX35  Thought all Autos had  HY35...MY Bad

No sir.

The 98.5-2002 manuals had the hx35

The 98.5-2000 autos had the hx35

2001-2002 autos had the hy35

The 01 and 02 also had torque management on the autos. Trust me on this I know I am right.

Well....  I guess it's time for a little closure on this thread.  I'll create another for my newly discovered head gasket challenges.

 

 

Boost leak: 

 

Apparently turned out to be a boost elbow adjustment issue.  After turning in the allen adjuster about 3-4 turns I'm now boosting away.  Thanks a ton for everyone's input.  Lesson learned... my ebay "pre-adjusted" elbow, was not adjusted properly as best I can tell.

 

 

Turbo Noise above 20psi: 

 

I think it's just the sound of it spinning faster than I've ever heard before, because before today I've never heard my truck boost over 21 psi, and now it's doing up to 30.  After pulling the boot on the intake side I checked the turbine, and had very little side to side movement (the kind it's supposed to have), and absolutely no front to back movement that I could tell.  All in all seems to be a pretty tight turbo. 

 

My thanks to all who helped.  I think this thread must have saved me a bit of cash somewhere along the line, so I think it only fair to up my donation a bit.

Turbo will have a high pitch whine like when you start reaching 30-35 PSI.

No sir.

The 98.5-2002 manuals had the hx35

The 98.5-2000 autos had the hx35

2001-2002 autos had the hy35

The 01 and 02 also had torque management on the autos. Trust me on this I know I am right.

 

EDITED:  LIKE I said after reading your POST.......I DIDNT Know the 99"s had HX35  Thought all Autos had  HY35...MY Bad

THANK YOU