Say goodbye to that ridiculously restrictive grid heater! Contrary to popular belief, the grid heater is NOT necessary for cold weather startup. The Longhorn Fab Shop Grid Heater Delete Plate for the LBZ and LMM trucks is a great install for Duramax owners. Don't accept the under designed factory grid heater and take a stand. This grid heater delete increases turbo spool up, fuel mileage, reduces EGTs, and allows you to easily port for a boost gauge, nitrous and water/meth. This is a great bolt-in piece that takes your truck to the next level.
At high boost levels there can be over 2 PSI of pressure drop across the stock and restrictive grid heater. A 2 PSI pressure drop means that your engine is seeing 2 PSI less boost than the engine is producing, resulting in a lower horsepower and torque number, higher EGTs, and slow spool times.
For this install, Diesel Tech magazine hooked up with Longhorn Fab Shop and an LB7.
Step 1
Disconnect both batteries.
Step 2
Remove the intake from the truck.
Step 3
Use a TORX T30 to remove the resonator bolt. Loosen the clamp that holds the resonator to the turbo inlet and remove the resonator.
Step 4
Use a TORX T30 to remove the three bolts that secure the wiring harness to the top of the intake tube.
Step 5
Flip open the black cover on top of the grid heater, remove 10mm nut, and remove red power wire.
Step 6
Place the supplied piece of heat shrink tube over the end of the red power wire, leaving about a half-inch overhang on the end. Using a heat source, shrink the tubing around the wire and pinch the half-inch end that is overhanging with a pair of pliers to close it off.
Step 7
Unhook the wire for the MAF sensor, Grid Heater sensor/control and alternator wire.
Step 8
Remove the 10mm bolt that holds the wiring harness tab to the intake tube.
Step 9
Squeeze clamp and remove PCV tube from turbo inlet.
Step 10
Loosen the band clamp for the turbo inlet and remove from turbo.
Step 11
Using a 12mm deep well socket and extension, remove 4x EGR Bolts and 2x Intake Y-Bridge bolts.
Step 12
The 12mm intake tube support bolt (located where the intake tube connects to the intercooler tube) can best be removed with the open end of a wrench just a few turns at a time.
Step 13
Using a flathead screwdriver, pry the boost tube retaining ring up and then gently slide it off using your hands. Be careful not to bend it as you will need to reinstall this.
Step 14
Slide the wiring harness that is on top of the intake tube toward the firewall and pull the intake tube straight up, removing it from the truck.
Step 15
Remove the 2x 12mm nuts and the 2x 6mm socket cap screws to separate the intake from the grid heater.
Step 16
Remove grid heater and replace with the Longhorn Fab Shop Grid Heater Delete, making sure that one metal gasket is on each side before reassembling the intake tube.
Step 17
Reassemble the components back on the truck.
Step 18
Using EFILive:
LBZ: Table C6001 and change P0540 "Intake Air Heater Circuit" to X: Not Reported, No MIL.
LMM: Table C6001 and change P154D - P154C - P154A "Intake Air Heater Feedback Circuit" to X: Not Reported, No MIL and P154B - P0640 - P166B "Intake Air Heater Circuit" to X: Not Reported, No MIL.
If the truck does not have EFILive, the check engine light will illuminate, but will not cause a reduced power code.
Quick Tips:
*Install the intake support bolt before tightening the EGR/Y-Bridge bolts; it will make it easier to line up since that bolt can be hard to start.
*When replacing the turbo inlet, make sure the clamp is as far open as it can be. Take your time and make sure the inlet is sitting flush with the turbo. It helps to have an extra set of hands here to help tighten down the clamp while you hold the turbo inlet in place.
*The PCV tube can be difficult to put back on the turbo inlet because it has a rubber grommet inside the plastic housing. It is often easier to take the grommet out of the PCV tube and place it on the turbo inlet and then slide the PCV tube plastic housing over that with the clamp.