new turbo, bad boost stock, great with tune

[dclifford]

2003 f250 6.0 150k.

I had a new turbo installed and when i picked the truck up the truck was not producing power as before with the bad turbo (the truck ran fantastic with the original turbo but when i purchased it looked like a screw of nut when through it). took it back and the shop said it tested as a bad turbo and replaced it. The truck ran better but it has never been the same..... unless I run it with a bully dog gt tuner then it has bonkers power!! But without the tuner there is very little power tons of lag and power is only produced successfully at 3000-3500 rpm. I have cleaned out the maps tube, and a new egr valve. The truck is operable and i drive it 200 miles per day, I just want to get this figured out. And perhaps de-tune the truck as i want it to last a good while. Thanks for the input.

[HAM_RADIO_MAN]

There is a turbo re-learn that might need to be done for your 03. Use the search button and I am sure you can find it. If I can locate it soon I will post it up. Do you have any trouble codes?

[dazdillenger]

Does it make any new noises? Like a shop vac?

[dclifford]

The only codes are, 7 glow plugs( loose connection) and the egr which has been replaced. I have tried the turbo relearn process. It only makes the vaccuum noise (as if the motor is gasping for air) when the tune download is uninstalled. When installed, regardless of setting it runs good.

I did forget to mention with the old turbo I was able to power brake and build boost/power. Now while power breaking I must roll 15-30ft while the throttle is mashed to get a power brake result.

[Lilpooh]

Check your up-pipe and y-pipe flex joints for cracks, also the y-pipe to turbo connection. Look for soot at these places, you may have an exhaust leak between the exhaust manifold and turbo.

[dazdillenger]

There is little doubt, you have a leak. From the sounds of it, a cracked or damaged y-pipe or collector. It also can't hurt to clean your Exhaust Backpressure sensor.

Put your tune on the smokiest setting, and put something over the exhaust pipe-there should be soot around the leaks.

[dclifford]

Will check this out. Thanks guys.

[dclifford]

Found one exhaust stud broke. Is this enough to cause such a severe lag?

[dazdillenger]

Which bolt? If it's a manifold bolt, no. If it;s a up-pipe bolt, possibly, but doubtful. I'd bet the y-pipe isn't seated properly to the turbo.

[dclifford]

Driver side closest to the fire wall. I checkedfor soot in the vicinity of the y pipe/ turbo do I need to uninstall and reinstall. Tell y'all what I am beginning to not like putting the vehicle in the shop. This was the first time and likely the last. Just want it done right.

Is there a trick or process for checking the y pipe seat? I looked for soot didn't see any.