Engine/Transmission (1998.5 - 2002) I think that I'm losing Boost.....

[Motorhead]

I hear a slight hiss when I have the window down and accellerating. I towed my car trailer today up some hills and It seemed to come in at 14 psi and above. I can only get 23psi with the HY turbo. I have an Edge EZ set on the second level and DDIIs. I think that I did see 26 before. What is the best way to find where the leaks are? I removed the intake horn when I put in the injectors. Do those gaskets blow out at the grid heater? Should I see more than 23psi with the HY? Any help appreciated

 

[krs]

You don't describe the hills or whether your trailer was loaded, but on the face of it 23 lbs. ain't bad. Boost goes up in relation to engine loading and with your power you may not have been giving your engine much work.



Could the noise you hear be the normal turbine whine? It can be hard to hear the turbo with stock air intake and the windows up, but not so hard with windows down.

 

[OL RATLR]

losing power

Put a turnbuckle on waste gate and have fun. Oo.

 

[LSMITH]

Chris, did you disable the wastegate and see what that did? 26 is too low and 23 is WAY too low. You should pull 32 in a flash, 35 or more if you load the truck. The only way to find a leak that only leaks at pressure is to pressure test the system, which is fairly easy if you have a compressor. Buy a PVC cap and install it in the first boot off the turbo on the charge side. Hook up a REGULATED air source, start at about 5 psi and work up to 25 fixing any leaks you may find.



You also could just pull all the boots off and clean them with alcohol, inspect them and then re-install them.

 

[willyslover]

also check for exhaust leaks, blown out gaskets, ect.

check end play of the turbo. . it might be binding up and on it's way out. . probably not but worth a check

 

[Mad Bomber]

Boost

One way you can tell if you have a leak is runnin down the freeway,you should hold 3 or 4 lbs of boost. , with the cruise control on. If it seems to surge and the boost falls to zero then builds it and then falls. One thing to check is the boost clamps on the rubber boots,they should be toqued to 95 inch lbs. Eric

 

[Greg Boardman-RIP]

I had the same symptoms. After hearing the hiss with window down I started to investigate. Drivers side lower intercooler boot was leaking. Had small hole in it from rubbing on inner fender well.

 

[Motorhead]

Howard, should I see that much boost with the HY?? Thanks for the things to ck. I have a compressor and if I have to, I'll try that.

 

[LSMITH]

Chris, yes the HY will still move plenty of air, with 2's and the EZ 30 is the absolute minimum I would look for... .

 

[Motorhead]

Howard, 30 psi with the waste gate working or disabled? My SPA shows a max of 24. Do you think that the HX 35 off of a '02 HO would help with EGTs?

 

[krs]

I get 35 out of the stock turbo using an EZ with boost elbow and 275s but ONLY under a heavy load in a too high gear. There's a steep (about 20%?) section of road near here that I use to road test and that's enoiugh to get max effort even with the truck unloaded,

Most of the time it seldom pulls more than 25 with occasional flashes of 30.

 

[Motorhead]

KRS, Do you have the Hy 35 or the HX 35? If you are a stick then you have the HX 35. If you have a pre 2000 automatic, I think that you have the HX 35. Chris

 

[krs]

I was referring to the 2001 6sp. but both of our trucks give much the same boost with ekbows. The 1997 is an auto hy35

with a TST plate but stock injectors.



Sorry - my sig. didn't post in that last.



--hmmm, didn't post this time either even though I made sure the box is checked. Anyway, see profile.

 

[Motorhead]

THX!!