Help! My 03 Ram 5.7 Hemi is running bad.

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OAFSquirrel

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2003
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Hemi 5.7
Hey everyone!


I've got an 03 Ram 1500 5.7 4x4 Quad Cab SLT. It has 238,000 miles. (300 miles on complete block rebuild). Heres what happened...


About 10 months ago I put dual exhaust from cat back on the truck. Then did a cold air intake.


About 8 months ago, I was driving through a neighborhood in the rain. And my truck made a bang sound and died at the stop sign. I started it back up and it drove rough. Had to 2 foot it to get home. (No CEL!)


Took it to a dealership for a diagnostic and they said i needed a catalytic converter and a new engine (high miles).... i took it home and did a back pressure test and pre-cat was ~1psi. Post cat was the same. Then I did an exhaust manifold temperature test revealed about 150°F bank 1 and ~400°F bank 2 I believe.


I decided to pull the head and had a broken #7 exhaust spring and bent pushrod. I rebuilt the head with new valve seals, springs, retainers. Replaced the lifters and pushrods as well. Put it together and found out I missed the hole for #5 intake pushrod... oops. Luckily it just slipped out and was still true (straight). My LTFT was -33% and STFT was -4% to -8%. Truck ran rough especially from idle to 2k rpm. Above 2k rpm was -12% LTFT. Compression test showed all within 10 psi after I fixed the pushrod. (NO CEL!)


I decided to rebuild the engine. (Master rebuild kit). I replaced the whole intake manifold, TB, ECT sensor, MAP sensor, both O2 sensors (b1s1&b1s2), IAT sensor, and PCV. (NO CEL!)


***Here's my problem:


*The truck still runs -11% to -14% LTFT and +3% to +4% STFT.


*MAP is showing 14"HG at idle, 21"HG at 2k RPM, 26"HG at WOT@4k rpm and deceleration from 4k rpm is 3-7"HG


*idle is rough with odd smelling exhaust cant tell if its oil or extremely rich (there is smoke coming out only when sitting at idle)


*very sluggish acceleration, 2k rpm or less has violent shake while driving


Any help of what to check next is extremely helpful.


Currently only 1 CEL code (evap "very small leak")
 

MADDOG

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Sounds like a flat or damaged cam lobe to me.
 
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OAFSquirrel

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Thanks for the quick reply MADDOG.

When I rebuilt the motor, there was no damage visible or physically "feelable" on the lobes themselves. They were still smooth.
 
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OAFSquirrel

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In the morning, I can post a picture of the live data from my autel MX808. The truck is rather loud with the cherry bomb muffler.
 

Redtruck-VA

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From your description I'm going to guess you hydro-locked the motor. Fuel trims are directly associated with O2s. I would use only dealer sensors or stick the old ones back in. I have had incredible poor luck with replacement sensors.
 

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