OEM Cadillac DeVille Intake Manifold

Cadillac DeVille Intake Manifold Parts and Q&A

• Intake Plenum
  12555840
  Q: How to replace the intake manifold on Cadillac DeVille?

  A:

  Start by removing 2 nuts that hold the Intake Manifold sight shield then remove the shield from the engine. Disconnect all wiring connections between coil module devices from camshaft surface covers and remove pcv valves from the camshaft housing along with the pcv fresh air tube while also separating the vacuum tubes from the air solenoid as well as removing the fuel regulator vacuum tube. Start by disconnecting the quick-connect fittings at the Fuel Rail for fuel inlet and return and then remove the rear lift bracket retaining nut. Disassemble the engine coolant heater system by removing its 2 pushnuts and placing the wire aside for future use. The surge tank pipe should be carefully moved out of the way from the Fuel Rail studs before disconnecting the 8 electrical connectors from the 8 Fuel Injectors. Four bolts secure the Fuel Rail to its position on the Intake Manifold. Removal of these bolts allows lifting the complete assembly of Fuel Rail and injectors from the Intake Manifold. Start by unclamping the plenum duct at the rear of the Intake Manifold then remove the 10 bolts securing the Intake Manifold to each Cylinder Head before gently lifting upward from the front of the Intake Manifold. You must check the Intake Manifold for cleanliness before applying a thin layer of grease to the rubber plenum duct's inner edge and removing debris from the Cylinder Head or Intake Manifold. Reposition the Intake Manifold with PCV Valve hose tightly attached to its front fitting and ultimately position the manifold before tightening the 10 bolts that secure it to cylinder heads. Support instructs to feed manifold rear portion into plenum duct before allowing manifold front to sink onto cylinder heads. Start installation of the 10 bolts that attach the Intake Manifold to the cylinder heads by tightening the center bolt first followed by an outward circular pattern to a torque setting of 10 nm on each. Tighten the plenum duct clamp at 2.25 nm after making sure it fully attaches to the Intake Manifold rear. Push the complete Fuel Rail assembly together with its attached injectors into their designated Intake Manifold places before bolting and torquing them to 10 nm. First connect the 8 electrical connectors to each Fuel Injector while placing surge tank pipes onto Fuel Rail studs and positioning engine coolant heater wire to Fuel Rail studs for vehicles with this feature. Install the 2 pushnuts and secure the Fuel Rail bracket retaining nut to the rear lift bracket while tightening it to 10 nm. Attach the quick connect fittings to the Fuel Rail before connecting the vacuum tubes to the air solenoid and fuel regulator vacuum tube. Complete the series of connections by attaching the pcv fresh air tube to the camshaft cover and the PCV Valve to the same location as well as the coil module connectors to the coil modules on each camshaft cover. Follow these steps to detect fuel leaks: turn the ignition to on for two seconds followed by off for ten seconds and then switch it back to on. Position the Intake Manifold sight shield to the engine and complete the installation by using two sight shield nuts that should be tightened to 3 nm torque.
• Intake Manifold
  19330172
  Q: How to service and repair the intake manifold on Cadillac DeVille?

  A:

  In order to serve and repair the Intake Manifold, start by removing two nuts off the Intake Manifold sight shield and then remove the sight shield from the engine. Unplug the coil harness at the camshaft covers, the pcv dirty air tube, the pcv fresh air tube, the fuel regulator canister, and the vacuum to the air solenoid. Unscrew the fuel inlet and return quick-connect fittings at the Fuel Rail as well as the Fuel Rail bracket retaining nut in the rear lift bracket. Take off the 2 pushnuts holding the engine coolant heater wire in place and store it to one side if available. Remove the 4 bolts that secure the Fuel Rail to the Intake Manifold and lift the entire Fuel Rail and injector assembly from the Intake Manifold and pull the 8 Fuel Injectors, at first disconnect the 8 electrical connectors from the 8 fuel injectors. Lease the plenum duct clamp at the rear of the Intake Manifold and remove the 10 bolt holding the Intake Manifold to the cylinder heads, then lift it with an upward movement at the front. Clean and inspect the Intake Manifold and rub a bit of light grease at the inner edge of the rubber plenum duct and clean the spot at the Cylinder Head or at the Intake Manifold. Replace the new gaskets onto the Intake Manifold after making sure the PCV Valve Hose is well put into the fitting at the front of the Intake Manifold before placing it. Mount the rear end of the Intake Manifold into the plenum duct, and insert the front into the cylinder heads. Loosely install the 10 bolts that secure the Intake Manifold to the cylinder heads, and tighten them in order to 10nm. Make sure that the plenum duct is well connected to the rear of the Intake Manifold and fasten the plenum duct clamp to 2.25 nm. Lube the intakes' fuel injectors bores with light mineral oil gm p-n 9981704, cleaners oil engine or equal, then replace the whole Fuel Rail installment of the engine inductor by pushing it in place. Mount the 4 bolts that secure Fuel Rail to the Intake Manifold and torque tightened at 10 nm. Attach the 8 electrical connectors to the fuel injectors, mount the engine coolant heater wire onto the Fuel Rail studs if so equipped, and install the 2 pushnuts. Install the Fuel Rail bracket retaining nut and tighten it to 10 nm, and then install quick connect fittings on the Fuel Rail. Ask someone to hold the vacuum tubes at the air solenoid, fuel regulator vacuum tube, pcv fresh air tube and pcv dirty air tube at the camshaft cover before attaching them to their respective connections along with the coil harness connectors. Turn on the ignition switch for 2 seconds, then switch to off for 10 minutes, and switch to on to observe for fuel leakages. Lastly, position the Intake Manifold sight shield to the engine and the 2 sight shield nuts having tightened them to 3 nm.