Manifold gaskets Is the upper maifold only one gasket to change? There are 4 gaskets. How many are there in the lower.

This is a vacuum leak causing the oxygen sensors to throw codes or its both sensors or you have an exhaust leak before the sensorsyou say you changed the intake manifold gasket did you change upper plenum and the lower intake or just the top? Ok let's try this take fuel injection cleaner and spray around the intake upper and lower while in drive foot on the brake if the idle changes the leak is there do the same for all vacuum lines

REMOVE UPER INTAKE 97 EXPLORER V6 4.0 - YouTube

? 12:22
https://www.youtube.com/watch?v=ugExJ0wkP8A
Jun 11, 2013 - Uploaded by Sum Guy
REMOVE UPER INTAKE 97 EXPLORER V6 4.0 ... I was told that all I have to do is remove the fan belt to get access to it ... FordExplorer 2000 intake manifold gasket upper lower P0174 by froggy - Duration: 36:54. by froggy 36,588 views ... Ford Explorer 4.0L SOHC Rough Idle P0171 P0174 Lean Codes ...

Putting the lower intake on my 1997 Ford Explorer 4.0 OHV ...

? 5:23
https://www.youtube.com/watch?v=qKE1vPxqPHs
Jun 27, 2010 - Uploaded by origionaldz
Putting the lower intake on my 1997 Ford Explorer 4.0 OHV sport .... I do have a 2000 5.0 ... @michaelheiland123654 To dothis job, you have to remove the alternator, unbolt the AC compressor, remove upper intake manifold, remove fuel rail,remove all injectors, ... Do you have the SOHC or OHV version?

1999 Ford Explorer 4.0L -need assistance on removing upper intake ...

www.automotiveforums.com > ... > Ford > Explorer ' Explorer Sport Trac

Sep 20, 2011 - 1999 Ford Explorer 4.0L -need assistance on removing upper intake ...Are you sure you have the OHV/pushrod engine and not the SOHC engine? ... Do youhave the upper intake manifold loose, you just are unable to ... the lower intake gasket, valve cover gaskets, Injector o-rings, plugs and wires. Thanks ...

How to replace upper intake manifold gaskets - Ford Explorer

This is going to be a pain, due to the age and rust. I assume when you say upper exhaust gasket. You are referring to the manifold to head gasket. If so you need to soak the stud/nuts with PB Blaster lube then back out the nuts, to remove the manifold. For the lower gaskets I assume you are referring to the donut gaskets where the pipes meet, I am pretty sure this model does not use donut gaskets.

3.8L Engine (most common) Upper Intake Manifold To Remove:

1. Drain the cooling system.
2. Remove or disconnect the following:
   • Negative battery cable.
   • Fuel injector sight shield.
   • Air cleaner intake duct.
   • Right spark plug wires from the ignition control module and reposition.
3. Relieve the fuel pressure.
4. Remove or disconnect the following:
   • Fuel rail assembly.
   • Brake booster hose from the vacuum source manifold in the upper intake manifold.
   • Exhaust Gas Recirculation Valve (EGR) wiring harness heat shield nut, bolt and the EGR heat shield.
   • Throttle body support bracket upper bolt.
5. Disconnect the electrical connectors from the following:
   • EVAP purge solenoid
   • Throttle Position (T/P) sensor
   • Idle Air Control (IAC) valve
   • Manifold Absolute Pressure (MAP) sensor
   • Mass Air Flow (MAF) sensor
   • EVAP purge solenoid vacuum line from the throttle body.
   • Accelerator and the cruise control cables with the bracket from the throttle body.
6. Remove or disconnect the following:
   • Upper intake manifold bolts and stud.
   • Clean the upper intake manifold bolt threads.
7. Remove or disconnect the following:
   • Upper intake manifold by lifting the back of the intake and sliding the manifold forward from the throttle body support bracket.
   • Upper-to-lower intake manifold carrier gasket from the upper intake manifold.
8. If the upper intake manifold is being replaced, remove the following:
   • Throttle body assembly.
   • Manifold Absolute Pressure (MAP) sensor.
   • Positive Crankcase Ventilation (PCV) valve.
   • Vacuum source manifold.

Upper intake manifold bolt torque sequence (3.8L engine)

To Install:

1. If the manifold was replaced, install or connect the following:
   • Vacuum source manifold.
   • Positive Crankcase Ventilation (PCV) valve.
   • Manifold Absolute Pressure (MAP) sensor.
   • Throttle body assembly.
   • Upper-to-lower intake manifold carrier gasket to the upper intake manifold.
2. Carefully place the upper intake manifold onto the lower intake manifold. Ensure that the alignment pins in the upper intake manifold align with the holes in the lower intake manifold. NOTE: Apply thread lock compound, to the bolt threads before assembly.
   
3. Install or connect the following:
   • Upper intake manifold. Tighten the upper intake manifold bolts in sequence to 89 in lbs (10 Nm)
   • Accelerator and the cruise control cables with the bracket to the throttle body.
   • EVAP purge solenoid vacuum line to the throttle body.
4. Connect the electrical connectors to the following:
   • Mass Air Flow (MAF) sensor
   • Manifold Absolute Pressure (MAP) sensor
   • Idle Air Control (IAC) valve
   • Throttle Position (T/P) sensor
   • EVAP purge solenoid
5. Install or connect the following:
   • Throttle body upper support bracket bolt. Tighten the bolt to 89 in lbs (10 Nm)
   • EGR valve wiring harness heat shield, nut and the bolt. Tighten the nut and the bolt to 89 in lbs (10 Nm)
   • Brake booster hose to the vacuum source manifold.
   • Fuel rail assembly.
   • Right spark plug wires.
   • Air cleaner intake duct.
   • Fuel injector sight shield.
6. Connect the negative battery cable.
7. Fill the cooling system.
8. Inspect for fluid or vacuum leaks.

Lower Intake Manifold (W/O Supercharger) To Remove:

1. Remove or disconnect the following:
   • Upper intake manifold.
   • Generator brace.
   • Drive belt tensioner with the mounting bracket and the heater water bypass inlet pipe.
   • Exhaust gas recirculation EGR outlet pipe bolt from the lower intake manifold.
   • Radiator inlet hose from the water outlet housing.
   • ECT sensor electrical connector.
   • Right upper engine mount strut bracket.
   • Generator brace bracket bolts.
   • Generator brace bracket.
   • Lower intake manifold bolts.
   • Lower intake manifold.
   • Lower intake manifold seals.
   • Lower intake manifold gaskets.
2. If replacing the lower intake manifold, Remove or disconnect:
   • Water outlet housing bolt and stud
   • Water outlet housing
   • Gasket and the thermostat.
   • ECT sensor.
3. Inspect the flatness of inlet flanges.
4. Clean the intake manifold mating surfaces.
5. Clean the intake manifold bolts and bolt holes of adhesive compound.

To Install:

1. If removed, install the ECT sensor.
   • Tighten the ECT sensor to 18 ft. lbs. (25 Nm)
2. If removed, install the thermostat, the gasket, and the water outlet housing.
3. If removed, install the water outlet housing bolt and the stud.
   • Tighten the bolt and stud to 20 ft. lbs. (27 Nm)
4. Install or connect the following:
   • Lower intake manifold gaskets. NOTE: Apply sealer GM P/N 12346286 (Canadian P/N 10953472) or equivalent to the ends of the intake manifold seals.
     
   • Lower intake manifold seals.
   • Lower intake manifold.
   • Lower intake manifold bolts.
   NOTE: Apply thread lock compound GM P/N 12345382 (Canadian P/N 10953489) or equivalent to the two hidden bolts and ensure they are installed.
   
5. Tighten the lower intake manifold bolts in sequence to 11 ft. lbs. (15 Nm)
   
   
6. Install or connect the following:
   • Generator brace bracket.
   • Generator brace bracket bolts. Tighten the bolts to 37 ft. lbs. (50 Nm)
   • Right upper engine mount strut bracket.
   • ECT sensor electrical connector.
   • Radiator inlet hose to the water outlet housing.
   • EGR outlet pipe to the lower intake manifold.
   • EGR outlet pipe bolt to the lower intake manifold. Tighten the bolt to 21 ft. lbs. (29 Nm)
   • Drive belt tensioner.
   • Generator brace.
   • Upper intake manifold.
7. Inspect for leaks.

Lower Intake Manifold (W/ Supercharger) To Remove:

1. Disconnect the negative battery cable.
2. Drain the cooling system.
3. Remove the supercharger.
4. Remove the thermostat housing.
5. Remove the EGR pipe at the intake manifold.
6. Disconnect the electrical connection at the temperature sensor.
7. Remove the intake manifold and gaskets.

NOTE: The coolant bypass tube will release from the intake manifold when the manifold is removed.
To Install:

1. Clean the gasket sealing surfaces.
2. Install the intake manifold gaskets.
3. Align the coolant bypass tube with the opening in the intake manifold and install the manifold. Tighten the bolts to 11 lb ft (15 Nm).
4. Install the electrical connector to the temperature sensor.
5. Install the EGR pipe to the intake manifold.
6. Install the thermostat housing.
7. Install the supercharger.
8. Fill the cooling system.
9. Connect the negative battery cable.

There are several areas to check for possible exhaust leaks. i will list them below.

1. Exhaust manifold gaskets - This will be the most common area. There is a gasket that separates the block from the exhaust manifold. these gaskets can fail, thus, causing a exhaust leak at the manifold.

2. Lower manifold gasket(donut gasket) - This will be a possible leak spot as well. This small circular gasket is placed in between the upper exhaust pie and the lower side of the manifold. It basically separates the pipe from the exhaust manifold.

3. Exhaust pipe - The entire pipe can rust overtime, thus, creating small holes along the pipe structure. These holes will cause the exhaust to leak ,thus, filling the vehicle will moderate fumes and causing louder than normal engine sounds during revving.

4. Muffler - This component can also deteriorate to the point that it cannot filter out the noise. It will also cause leaks as well.

You will find the leak in one or all of the areas stated above in the list.

Head gasket, if you have a V6 or a V8, can't tell which one is at fault, so both will might as well be changed.
If the leak near the maifold is oil, the valve cover gaskets are leaking.
When head gaskets are changed, all the necessary gaskets come in the gasket kit.

Code P0302 is misfire cylinder Number 2
Could be spark plug, wire or coil

P0171 & P0174 Running Lean
Vaccum leak Possible intake leak or PCV system leak.

3.8L Engine

NOTE The 3.8L (VIN K) non-supercharged engine uses a two-piece intake manifold consisting of an upper air plenum which mounts the throttle body and a lower intake manifold assembly which houses the fuel injectors. The 3.8L (VIN 1) supercharged engine uses a similar lower intake manifold. The supercharger serves as the upper manifold.
Lower Manifold

NOTE Two bolts which fasten the lower intake manifold to the cylinder head are accessible only after the upper intake manifold is removed. These bolts are located in the right front and left rear corners of the lower intake manifold. Remove the upper intake manifold to service the lower intake.
The 3.8L (VIN 1) supercharged engine uses a manifold similar to the 3.8L (VIN K), but the supercharger serves as the upper manifold.

1. Disconnect the negative battery cable.
2. On 3.8L (VIN 1) engines, remove the supercharger assembly. Please see the procedure in this section.
3. Remove the upper intake manifold using the procedure above.
4. Remove the EGR outlet pipe from the intake manifold.
5. Detach the engine coolant temperature sensor wiring harness from the sensor.
6. Remove the lower intake manifold bolts and carefully lift off the manifold.

To install:


Fig. Lower intake manifold bolt torque sequence-3.8L (VIN K) engine

1. Clean all parts well with degreaser, especially the gasket seal surfaces on the upper and lower manifold pieces and between the lower manifold and the cylinder heads..
2. Install new gaskets to the cylinder heads and new seals to the engine block. Carefully lower the manifold into place. Apply thread-locking compound to the bolt threads. Make sure to install the two hidden bolts in the lower intake manifold. Hand start all bolts, then torque evenly to 11 ft. lbs. (15 Nm). Follow the toque sequence, starting in the center, then working outwards in a circle.
3. Install the remaining components in the reverse order of the removal process.

Upper Intake Manifold (Plenum)

1. Disconnect the negative battery cable.
2. On 3.8L (VIN 1) engines, remove the supercharger assembly. Please see the procedure in this section.
3. Tag for identification, then remove the right side spark plug wires.
4. Disconnect the ignition wires from the fuel rail.
5. Remove the fuel rail. Please see Section 5.
6. Remove the cable bracket from the intake manifold.
7. Remove the throttle body.

NOTE Two bolts which fasten the lower intake manifold to the cylinder head are accessible are accessible only after the upper intake manifold is removed. These bolts are located in the right front and left rear corners of the lower intake manifold.

1. Remove the upper intake manifold bolts and carefully lift the upper intake manifold from the engine.

Fig. Upper intake manifold and bolt torque sequence-3.8L (VIN K) engine
To install:

1. Clean all parts well with degreaser, especially the gasket seal surfaces on the upper and lower manifold pieces.
2. Install new gaskets to the cylinder heads and new seals to the engine block. Carefully lower the manifold into place. Make sure to install the two hidden bolts in the lower intake manifold. Hand start all bolts, then torque evenly to 89 inch lbs. (10 Nm). Follow the torque sequence, starting in the center, then working outwards in a circle.
3. Install the remaining components in the reverse order of the removal process.

It will smoke for a little while the new gasket is settling in.