Fastener Tightening Specifications
| Application | Specification | |
|---|---|---|
| Metric | English | |
| Catalytic Converter to the Cylinder Head- First Pass Catalytic Converter to the Cylinder Head- Second Pass | 20 N.m | 15 lb ft |
| 46 N.m | 34 lb ft | |
| Catalytic Converter-Rear to Downpipe | 46 N.m | 34 lb ft |
| Catalytic Converter-Front to Rear Muffler | 46 N.m | 34 lb ft |
| Exhaust Heat Shield Fasteners | 8 N.m | 71 lb in |
Fastener Tightening Specifications
Adhesives, Fluids, Lubricants, and Sealers
| Application | Type of Material | GM Part Number | |
|---|---|---|---|
| United States | Canada | ||
| Anti-Seize | Lubricant | 88862477 | 88862478 |
Adhesives, Fluids, Lubricants, and Sealers
Symptoms - Engine Exhaust
- Review the exhaust system description in order to familiarize yourself with the exhaust system components and the intended function of the components. Refer to «Exhaust System Description»(/cadillac/srx/ii-2012-2016/remont/exhaust/#engine-exhaust-system__exhaust-system-description) .
- All diagnostics on a vehicle should follow a logical process. Strategy Based Diagnostics is a uniform approach for repairing all systems. The diagnostic flow is the place to start when repairs are necessary and may always be used in order to resolve a system problem. For a detailed explanation, refer to «Strategy Based Diagnosis»(/cadillac/srx/ii-2012-2016/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__strategy-based-diagnosis) .
Visual/Physical Inspection
- Inspect for aftermarket or non-OEM devices such as, but not limited to; tailpipe extensions, headers, and exhaust cutouts. Any aftermarket exhaust system devices could affect the operation and proper performance of the exhaust system.
- Verify the exact operating conditions under which the concern exists. Note factors such as engine RPM, engine temperature, engine load, and frequency of concern.
- Inspect the easily accessible or visible system components for obvious damage or conditions which could cause any symptom.
Intermittent
Test the vehicle under the same conditions that the customer reported in order to verify the system is operating as designed.
Symptom List
Refer to a symptom diagnostic procedure from the following list in order to diagnose the symptom
- Loss of power Refer to «Restricted Exhaust»(/cadillac/srx/ii-2012-2016/remont/exhaust/#engine-exhaust-system)
- Poor acceleration Refer to «Restricted Exhaust»(/cadillac/srx/ii-2012-2016/remont/exhaust/#engine-exhaust-system)
- Poor fuel economy Refer to «Restricted Exhaust»(/cadillac/srx/ii-2012-2016/remont/exhaust/#engine-exhaust-system)
- Excessive smoke diesel Refer to «Restricted Exhaust»(/cadillac/srx/ii-2012-2016/remont/exhaust/#engine-exhaust-system)
- Exhaust hissing noise Refer to «Exhaust Leakage»(/cadillac/srx/ii-2012-2016/remont/exhaust/#engine-exhaust-system__exhaust-leakage)
- Exhaust popping noise Refer to «Exhaust Leakage»(/cadillac/srx/ii-2012-2016/remont/exhaust/#engine-exhaust-system__exhaust-leakage)
- Exhaust rattle noise Refer to «Exhaust Noise»(/cadillac/srx/ii-2012-2016/remont/exhaust/#engine-exhaust-system__exhaust-noise)
- Loud exhaust noise Refer to «Exhaust Noise»(/cadillac/srx/ii-2012-2016/remont/exhaust/#engine-exhaust-system__exhaust-noise)
- Exhaust buzz, groan, hum noise Refer to «Exhaust Noise»(/cadillac/srx/ii-2012-2016/remont/exhaust/#engine-exhaust-system__exhaust-noise)
Special Tools
EN 35314-A Exhaust Back Pressure Gauge.
For equivalent regional tools, refer to Special Tools .
Diagnostic Aids
| WARNING | Refer to Hot Exhaust System Warning . |
For dual exhaust systems a quick check of exhaust flow will help determine which side of the exhaust system is restricted. The side that has less exhaust flow is the side that will be suspect, and diagnosis should begin there.
Test Description
The numbers below refer to the step numbers on the diagnostic table.
- 4 The exhaust system has very low back pressure under normal conditions. If the exhaust system is restricted, a significant increase in the exhaust pressure is noticed on the EN 35314-A gauge. Removing the HO2S sensor may set a DTC. When finishing this diagnostic table, be sure to clear all codes.
- 5 This step will isolate the catalytic converter from the remainder of the exhaust system.
- 8 Confirming that the condition has been fixed is essential. If the symptom still exists and the vehicle has a dual exhaust system, proceed to step 2 and repeat diagnostic procedure on the opposite exhaust pipe.
| Step | Action | Value(s) | Yes | No |
|---|---|---|---|---|
| 1 | Did you verify the customers complaint? | Go to Step 2 | ||
| 2 | Did you review the exhaust symptoms diagnostic information and perform the necessary inspections? | Go to Step 3 | Go to Symptoms - Engine Exhaust | |
| 3 | Is the system equipped with dual exhaust? | Go to Diagnostic Aids | Go to Step 4 | |
| 4 | Remove the heated oxygen sensor (HO2S) that is in front of the catalytic converter. Refer to the appropriate procedure. Refer to Heated Oxygen Sensor Replacement - Bank 1 Sensor 1 , or Heated Oxygen Sensor Replacement - Bank 2 Sensor 1 . Install the EN 35314-A Exhaust Back Pressure Gauge in place of the HO2S sensor. Start the engine. Increase and monitor the engine speed at 2,500 RPM. Observe the exhaust system back pressure reading on the gauge. Does the reading exceed the specified value? | 9 kPa (1.25 psi) | Go to Step 5 | Go to Step 8 |
| 5 | Turn the engine OFF and place the ignition in the lock position. Remove the EN 35314-A gauge. Reinstall the HO2S sensor. Refer to Heated Oxygen Sensor Replacement - Bank 1 Sensor 1 , or Heated Oxygen Sensor Replacement - Bank 2 Sensor 1 . Remove the post-catalyst HO2S sensor. Refer to the appropriate procedure. Refer to Heated Oxygen Sensor Replacement - Bank 1 Sensor 2 , or Heated Oxygen Sensor Replacement - Bank 2 Sensor 2 . Install the EN 35314-A gauge in place of the post HO2S sensor. Start the engine. Increase and monitor the engine speed at 2,500 RPM. Observe the exhaust system back pressure reading on the gauge. Does the reading exceed the specified value? | 9 kPa (1.25 psi) | Go to Step 6 | Go to Step 7 |
| 6 | Inspect the exhaust system for the following conditions: Damage in the exhaust pipe Debris in the exhaust pipe Muffler or resonator internal failure Two-layer exhaust pipe separation Did you find and correct the condition? | Go to Step 8 | ||
| 7 | Replace the catalytic converter. Refer to Catalytic Converter Replacement - Left Side (Front) , or Catalytic Converter Replacement - Right Side (Rear) . Did you find and correct the condition? | Go to Step 8 | ||
| 8 | Remove the EN 35314-A gauge. Reinstall the applicable HO2S sensor. Refer to Heated Oxygen Sensor Replacement - Bank 1 Sensor 2 , or Heated Oxygen Sensor Replacement - Bank 2 Sensor 2 . Clear any codes. Road test the vehicle in order to verify the repair. Did you correct the condition? | System OK | Go to Step 2 |
Exhaust Leakage
| Condition | Action |
|---|---|
| WARNING: Refer to Hot Exhaust System Warning . DEFINITION: An exhaust leak may show stains at the area of the leak. The leak may be felt by holding a hand close to the suspected areas or using a smoke pencil. The leak may make a popping or hissing noise.Refer to Symptoms - Engine Exhaust prior to beginning this table. | |
| Misaligned or improperly installed exhaust system components | Align and tighten the exhaust system components to the specifications. Refer to Fastener Tightening Specifications . Ensure the exhaust hangers are in the proper locations and not loose. |
| Exhaust leaks at the following connections: Exhaust manifold to pipe Flanges Pipe clamps | Tighten the components to the specifications. Refer to Fastener Tightening Specifications . |
| Seals or gaskets leaking; Exhaust manifold to cylinder head Exhaust pipes to exhaust manifold Catalytic converter connection | Replace the leaking seal or gasket. Refer to the affected components procedure for service. |
| Irregularities at the mating surfaces on the flange connections | Repair as required or replace the affected component. Refer to the affected components procedure for service. |
| Catalytic Converter cracked or broken | Replace the catalytic converter. Refer to Catalytic Converter Replacement - Left Side (Front) , or Catalytic Converter Replacement - Right Side (Rear) . |
| Exhaust system component connection welds leaking | Replace the leaking component. Refer to the affected component's procedure for service. |
| Muffler or resonator, if equipped, damaged or leaking at the seams | Replace the affected muffler or resonator, if equipped. Refer to Exhaust Muffler Replacement . |
| WARNING |
|---|
| Refer to Hot Exhaust System Warning . |
Exhaust Leakage
Exhaust Noise
| Condition | Action |
|---|---|
| WARNING: Refer to Hot Exhaust System Warning . DEFINITION: An audible or physical noise due to a faulty component or damaged components causing a loose or misaligned exhaust system resulting in a rattle or vibration noise, i.e. buzz, groan, hum.Refer to Symptoms - Engine Exhaust prior to beginning this table. | |
| Popping or hissing noise | Exhaust leak-Refer to Exhaust Leakage . |
| Loud exhaust | Compare to a known good vehicle. Inspect for a damaged or failed muffler or resonator, if equipped. Replace the faulty muffler or resonator (if equipped). Refer to Exhaust Muffler Replacement . |
| External rattle or vibration noise | Inspect for a bent or loose hanger, loose heat shield, or loose clamp. Inspect for a exhaust pipe causing interference. Repair or replace the affected component. Refer to the affected component's service procedure. |
| Internal rattle | Test the components by tapping with a rubber mallet to confirm a rattle. Replace the faulty catalytic converter, resonator, if equipped, or muffler. Refer to Exhaust Muffler Replacement . |
| WARNING |
|---|
| Refer to Hot Exhaust System Warning . |
Exhaust Noise
Removal Procedure
| WARNING | Refer to Exhaust Service Warning . |
| WARNING | Refer to Eye Protection Warning . |
- Raise and support the vehicle. Refer to «Lifting and Jacking the Vehicle»(/cadillac/srx/ii-2012-2016/remont/hoistjack/#general-information) .
- Remove the rear muffler fasteners (1) and discard the exhaust gaskets (2).
- Remove the rear catalytic converter fasteners (1) and discard the exhaust gasket (2).
- Remove the front catalytic converter fasteners (1) and lower the front catalytic converter with the downpipe (3) , to the floor.
- Discard the exhaust gasket (2).
Installation Procedure
- Position the front catalytic converter and the downpipe (3) onto the cylinder head with a NEW gasket (2).
- Loosely tighten the fasteners (1).
- Install the downpipe (4) onto the rear muffler (3) with NEW gaskets (2) and tighten the fasteners (1) to 46 N.m (34 lb ft).
- Install the downpipe (3) onto the rear catalytic converter with a NEW gasket (2) and tighten the fasteners to 46 N.m (34 lb ft).
- Tighten the catalytic converter fasteners (1) in a criss-cross pattern 46 N.m (34 lb ft) to 46 N.m (34 lb ft).
- Lower the vehicle.
- Start the engine and check for exhaust leaks.
Scheme 1
| Callout | Component Name |
|---|---|
| Preliminary Procedure Remove the left side catalytic converter. Refer to Catalytic Converter Replacement - Left Side (Front) . Disconnect the heated oxygen sensors before and after the right catalytic converter. | |
| 1 | Nut (Qty: 4) CAUTION: Refer to Fastener Caution . CAUTION: To prevent damage to the exhaust manifold flange or stud, make sure the flange is fully seated before tightening. Procedure Remove the right exhaust manifold nuts. Remove the right exhaust manifold studs on the right cylinder head (if necessary). Replace the nuts and gasket. Clean and inspect the studs on the engine cylinder head. Replace as necessary. Verify that the studs are fully seated. Stud collar should touch the surface of the engine cylinder head. Tighten nuts in a criss-cross pattern. Tighten First Pass: 20 N.m (15 lb ft) Final Pass: 46 N.m (34 lb ft) |
| 2 | Gasket NOTE: Improperly installed and/or leaking exhaust manifold gaskets may affect vehicle emissions and/or On-Board Diagnostics (OBD) II system performance. |
| 3 | Catalytic Converter |
| CAUTION |
|---|
| Refer to Fastener Caution . |
| CAUTION |
|---|
| To prevent damage to the exhaust manifold flange or stud, make sure the flange is fully seated before tightening. |
| NOTE |
|---|
| Improperly installed and/or leaking exhaust manifold gaskets may affect vehicle emissions and/or On-Board Diagnostics (OBD) II system performance. |
Catalytic Converter Replacement - Right Side (Rear)
| WARNING | Refer to Exhaust Service Warning . |
| WARNING | Refer to Eye Protection Warning . |
- Raise and support the vehicle. Refer to «Lifting and Jacking the Vehicle»(/cadillac/srx/ii-2012-2016/remont/hoistjack/#general-information) .
- Remove the rear muffler fasteners (1) and discard the exhaust gaskets (2).
- With the aid of a second technician, remove the muffler (2) from the exhaust isolators (1) and lower to the floor.
- Install the exhaust muffler (2) into the exhaust isolators (1).
- Install the exhaust muffler (3) into the front catalytic converter (4) with NEW gaskets (2) and tighten the fasteners (1) to 46 N.m (34 lb ft) .
- Lower the vehicle.
- Start the engine and check for exhaust leaks.
Scheme 2
| Callout | Component Name |
|---|---|
| WARNING: Refer to Exhaust Service Warning . WARNING: Refer to Eye Protection Warning . Preliminary Procedure Remove the exhaust muffler. Refer to Exhaust Muffler Replacement . | |
| 1 | Exhaust Heat Shield Fastener (Qty: 6) CAUTION: Refer to Fastener Caution . Tighten 8 N.m (71 lb in) |
| 2 | Exhaust Heat Shield |
| WARNING |
|---|
| Refer to Exhaust Service Warning . |
| WARNING |
|---|
| Refer to Eye Protection Warning . |
| CAUTION |
|---|
| Refer to Fastener Caution . |
Exhaust Heat Shield Replacement (Front)
Scheme 3
| Callout | Component Name |
|---|---|
| WARNING: Refer to Exhaust Service Warning . WARNING: Refer to Eye Protection Warning . Preliminary Procedure Remove the exhaust muffler. Refer to Exhaust Muffler Replacement . | |
| 1 | Exhaust Heat Shield Fastener (Qty: 4) CAUTION: Refer to Fastener Caution . Tighten 8 N.m (71 lb in) |
| 2 | Exhaust Heat Shield |
| WARNING |
|---|
| Refer to Exhaust Service Warning . |
| WARNING |
|---|
| Refer to Eye Protection Warning . |
| CAUTION |
|---|
| Refer to Fastener Caution . |
Exhaust Heat Shield Replacement (Rear)
Scheme 4
| Callout | Component Name |
|---|---|
| Preliminary Procedure If equipped with AWD, remove the right catalytic converter. Refer to Catalytic Converter Replacement - Right Side (Rear) | |
| 1 | Transmission Brace Bolt (MH4) WARNING: Refer to Exhaust Service Warning . CAUTION: Refer to Fastener Caution . Tighten 58 N.m (43 lb ft) |
| 2 | Transmission Brace Bolt (Qty: 2) Tighten 58 N.m (43 lb ft) |
| 3 | Transmission Brace (MH4) |
| 4 | Lower Heat Shield Bolt Tighten 9 N.m (80 lb in) |
| 5 | Lower Heat Shield Bolt Tighten 58 N.m (43 lb ft) |
| 6 | Exhaust Manifold Lower Heat Shield (MH2 Shown) |
| WARNING |
|---|
| Refer to Exhaust Service Warning . |
| CAUTION |
|---|
| Refer to Fastener Caution . |
Exhaust Manifold Lower Heat Shield Replacement
Exhaust System Description
Note. Use of non-OEM parts may cause driveability concerns.
The exhaust system carries exhaust gases, treated by the catalytic converter, through a resonator, if applicable and into the exhaust muffler where exhaust noise is lessened.
In order to secure the exhaust pipe to the exhaust manifold, a flange and seal-joint coupling is utilized. The exhaust system may utilize a slip-joint coupling design with a clamp and a U-bolt or a flange connection with a gasket.
Exhaust hangers and rubber insulators help to support the weight of the exhaust pipe along with insulating any exhaust system vibration, rattle, or noise.
Exhaust hangers also space the exhaust system away from the underbody of the vehicle and allows the exhaust system to expand as the exhaust system warms up.
Exhaust heat shields are used to protect the body and other components from damage due to the heat from the exhaust system.
The exhaust system may be comprised of the following components
- Exhaust manifold
- Exhaust pipes
- Catalytic converters
- Exhaust muffler
- Exhaust resonator, if equipped
- Exhaust tail pipe, if equipped
- Exhaust hangers
- Exhaust heat shields
Resonator
Some exhaust systems are equipped with a resonator. The resonator, located either before or after the muffler, allows the use of mufflers with less back pressure. Resonators are used when vehicle characteristics require specific exhaust tuning.
Catalytic Converter
The catalytic converter is an emission control device used to reduce hydrocarbons (HC), carbon monoxide (CO), and oxides of nitrogen (NOx) pollutants from the exhaust gas.
The catalytic converter is comprised of a ceramic monolith substrate, supported in insulation and housed within a sheet metal shell. The substrate may be washcoated with 3 noble metals
- Platium (Pt)
- Palladium (Pd)
- Rhodium (Rh)
The catalyst in the catalytic converter is not serviceable.
Muffler
The exhaust muffler reduces the noise levels of the engine exhaust by the use of tuning tubes. The tuning tubes create channels inside the exhaust muffler that lower the sound levels created by the combustion of the engine.
Illustration Tool Number/ Description J 35314-A Exhaust Back Pressure Gauge
Scheme 5
See also:
• Strategy Based Diagnosis
• Hot Exhaust System Warning
• Heated Oxygen Sensor Replacement - Bank 1 Sensor 1
• Exhaust Service Warning
• Eye Protection Warning
• Lifting and Jacking the Vehicle
• Fastener Caution
• Exhaust System Description
• Restricted Exhaust
• Exhaust Leakage
• Exhaust Noise
• Symptoms - Engine Exhaust
• Fastener Tightening Specifications