Low boost 3126e 2002

[walkerv]

I have been working on my service truck again , fixxed a fuel leak found and repaired two small boost leaks . Had a hard start/no start after shutting truck off when road hot ( this is fixxed it was timing speed sensors in the back of front cover)..
So i decided while im doing all this i will put guage on intake and fuel, fuel pressure is perfect. But most i can make is 13 psi boost it should be 20psi. Looked over cac cooler no aparent cracks in the usuall spots , i need to pressure test it to verify but ran out of time .
I suspect the wastgate in turbo is not sealing or is falling apart, i suspect this becuase everyonce in a while while on the road i will get into the throttle and all of a sudden the turbo whine will get what seems like twice as loud , its real noticable when you can hardly hear it to begin with.
The question is this a common problem on a higher mileage 3126e 210 hp at 2200, 605 torque at 1440 , if someone really wants the serial number i will venture out and open the hood . The prefix is CKM. Also i tried pinching off the hose to wastgate that didnt help .

 

[GregsHD]

I'd be digging into the guts of that turbo, probably plumb wore out.

 

[RZucker]

I have seen wastegate flappers "disappear" too.

 

[walkerv]

I have seen wastegate flappers "disappear" too.

I have too on the older 3116 it i think that turbo was designed different maybe not its been awhile since i have seen on in a truck, we have one in the fleet but its rarely there. I pretty much am gonna replace valve cover and base gaskets and run overhead while im there, and look for a cac test kit before i do a turbo . It is running alot better already but its a turd at the same time . This truck has a brake saver on it when i do flex pipe next week im going to look up in there and insure it is open all the way even though it seems to work properly and goes fully open from the outside .

 

[Truck Shop]

Just plug off CAC where the hump boots attach using old hump boots, hook up regulated air and put 20 psi against it and spray with soapy water. Sometimes you can hear it before you see it.

 

[RZucker]

Just plug off CAC where the hump boots attach using old hump boots, hook up regulated air and put 20 psi against it and spray with soapy water. Sometimes you can hear it before you see it.

Twice I have seen Kenworths break a radiator diagonal brace behind the CAC and rub a hole in the backside center.

 

[Truck Shop]

If it's a Freightliner the tubes crack at the sides or the CAC just cracks the tubes right in the middle top.

 

[walkerv]

If it's a Freightliner the tubes crack at the sides or the CAC just cracks the tubes right in the middle top.

Gmc c6500 they break on hotside top corner usually especially if it was in an acident . This one hasnt been . Unfortuently unless i buy a kit for checking cac or at least find some of the pluggs probably not gonna happen rite away, im triing to get two big projects out of the shop so i can totally clean it for an impending company gathering that takes place at the shop.