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Engine Exhaust System Cadillac ELR I

Exhaust 6 illustrations ~1131 words

Fastener Tightening Specifications

ApplicationSpecification
MetricEnglish
Catalytic Converter-to-Exhaust Muffler Clamp55 N.m41 lb ft
Exhaust Brace-to-Block Bolt22 N.m16 lb ft
Exhaust Heat Shield Retainers9 N.m80 lb in
Exhaust Manifold with Catalytic Converter-to-Brace Bolt22 N.m16 lb ft
Exhaust Manifold with Catalytic Converter-to-Cylinder Head Nut22 N.m16 lb ft
Exhaust Manifold with Catalytic Converter-to-Catalytic Converter Nut22 N.m16 lb ft
Exhaust Muffler Rear Hanger Bracket Bolts22 N.m16 lb ft

Fastener Tightening Specifications

Symptoms - Engine Exhaust

  1. Review the Exhaust System Description and Operation in order to familiarize yourself with the system functions. Refer to «Exhaust System Description»(/cadillac/elr/i-2013-2015/remont/exhaust/#engine-exhaust-system__exhaust-system-description) .
  2. 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.

Visual/Physical Inspection

  1. Inspect for aftermarket or non-OEM devices such as, but not including; tailpipe extensions, headers, and exhaust cutouts. This could affect the operation and proper performance of the exhaust system.
  2. Verify the exact operating conditions under which the concern exists. Note factors such as engine RPM, engine temperature, engine load, and frequency of concern.
  3. Inspect the easily accessible or visible system components for obvious damage or conditions, which could cause any symptom.

Intermittents

Test the vehicle under the same conditions that the customer reported in order to verify the system is operating as designed.

Symptom List

  1. Loss of power-Refer to «Restricted Exhaust»(/cadillac/elr/i-2013-2015/remont/exhaust/#engine-exhaust-system) .
  2. Poor acceleration-Refer to «Restricted Exhaust»(/cadillac/elr/i-2013-2015/remont/exhaust/#engine-exhaust-system) .
  3. Poor fuel economy-Refer to «Restricted Exhaust»(/cadillac/elr/i-2013-2015/remont/exhaust/#engine-exhaust-system) .
  4. Excessive smoke-diesel-Refer to «Restricted Exhaust»(/cadillac/elr/i-2013-2015/remont/exhaust/#engine-exhaust-system) .
  5. Exhaust hissing noise-Refer to «Exhaust Leakage»(/cadillac/elr/i-2013-2015/remont/exhaust/#engine-exhaust-system__exhaust-leakage) .
  6. Exhaust popping noise-Refer to «Exhaust Leakage»(/cadillac/elr/i-2013-2015/remont/exhaust/#engine-exhaust-system__exhaust-leakage) .
  7. Exhaust rattle noise-Refer to «Exhaust Noise»(/cadillac/elr/i-2013-2015/remont/exhaust/#engine-exhaust-system__exhaust-noise) .
  8. Loud Exhaust noise-Refer to «Exhaust Noise»(/cadillac/elr/i-2013-2015/remont/exhaust/#engine-exhaust-system__exhaust-noise) .
  9. Exhaust buzz, groan, hum noise-Refer to «Exhaust Noise»(/cadillac/elr/i-2013-2015/remont/exhaust/#engine-exhaust-system__exhaust-noise) .

Diagnostic Aids

A quick check of exhaust flow will help determine for gasoline engines.

Test Description

The numbers below refer to the step numbers on the diagnostic table.

  1. 3 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 exhaust back pressure gauge. Removing the heated oxygen sensor may set a DTC. When finishing this diagnostic table, be sure to clear all codes.
  2. 4 This step will isolate the catalytic converter from the remainder of the exhaust system.
  3. 7 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.
StepActionValue(s)YesNo
1Did you verify the customers complaint?Go to Step 2
2Did you review the exhaust symptoms diagnostic information and perform the necessary inspections?Go to Step 3Go to Symptoms - Engine Exhaust
3Remove the heated oxygen sensor 1. Refer to Heated Oxygen Sensor Replacement - Sensor 1 . Install the gauge in place of the heated oxygen sensor 1. Engine running, increase and monitor the engine speed at 2,000 RPM. Observe the exhaust system back pressure reading on the gauge. Does the reading exceed the specified value?14 kPa (2 psi)Go to Step 4Go to Step 7
4Vehicle OFF. Remove the gauge . Install the heated oxygen sensor 1. Refer to Heated Oxygen Sensor Replacement - Sensor 1 . Remove the heated oxygen sensor 2. Refer to Heated Oxygen Sensor Replacement - Sensor 2 . Install the gauge in place of the heated oxygen sensor 2. Engine running,increase and monitor the engine speed at 2,000 RPM. Observe the exhaust system back pressure reading on the gauge. Does the reading exceed the specified value?Go to Step 5Go to Step 6
5Inspect 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 7
6Replace the catalytic converter. Refer to Catalytic Converter Replacement . Did you find and correct the condition?Go to Step 7
7Remove the gauge. Install the heated oxygen sensor 2. Refer to Heated Oxygen Sensor Replacement - Sensor 2 . Clear any DTCs. Road test the vehicle in order to verify the repair. Did you correct the condition?System OKGo to Step 2

Restricted Exhaust

Exhaust Leakage

ProblemAction
WARNING: While engine is operating, the exhaust system will become extremely hot. To prevent burns avoid contacting a hot exhaust system. 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 componentsAlign and tighten the components to the specifications. Refer to Fastener Tightening Specifications .
Exhaust leaks at the following connections: Exhaust manifold to pipe Flanges Pipe clampsTighten 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 EGR connections AIR connections to the exhaust manifold or cylinder headReplace the leaking seal or gasket. Refer to the affected components procedure for service.
Irregularities at the mating surfaces on the flange connectionsRepair as required or replace the affected component. Refer to the affected components procedure for service.
Exhaust manifold cracked or brokenReplace the exhaust manifold. Refer to Exhaust Manifold with Catalytic Converter Replacement .
Exhaust system component connection welds leakingReplace the leaking component. Refer to the affected component's procedure for service.
Muffler or resonator, if equipped, damaged or leaking at the seamsReplace the affected muffler. Refer to Exhaust Rear Muffler Replacement .
WARNING
While engine is operating, the exhaust system will become extremely hot. To prevent burns avoid contacting a hot exhaust system.

Exhaust Leakage

Exhaust Noise

ConditionAction
WARNING: While engine is operating, the exhaust system will become extremely hot. To prevent burns avoid contacting a hot exhaust system. 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 noiseExhaust leak. Refer to Exhaust Leakage .
Loud exhaustCompare to a known good vehicle. Loosen exhaust clamp to reposition exhaust. Re-tighten clamp. Inspect for a damaged or failed muffler. Replace the faulty muffler. Refer to Exhaust Rear Muffler Replacement .
External rattle or vibration noiseInspect for a bent or loose hanger, loose heat shield, or loose clamp. Inspect for an exhaust pipe causing interference. Repair or replace the affected component. Refer to the affected component's service procedure.
Internal rattleTest the components by tapping with a rubber mallet to confirm a rattle. Replace the faulty catalytic converter, or muffler. Refer to one of the following procedures: Catalytic Converter Replacement Exhaust Rear Muffler Replacement
WARNING
While engine is operating, the exhaust system will become extremely hot. To prevent burns avoid contacting a hot exhaust system.

Exhaust Noise

Scheme 1

Scheme 1: Exhaust Manifold with Catalytic Converter Replacement
Scheme 1: Exhaust Manifold with Catalytic Converter Replacement
CalloutComponent Name
WARNING: Do not use a service jack in locations other than those specified to lift this vehicle. Lifting the vehicle with a jack in those other locations could cause the vehicle to slip off the jack and roll; this could cause injury or death. WARNING: Refer to Hot Exhaust System Warning . Preliminary Procedures Remove the drive motor battery coolant pump. Refer to Drive Motor Battery Coolant Pump Replacement . Disconnect the heated oxygen sensor. Refer to Heated Oxygen Sensor Replacement - Sensor 1 . Remove the catalytic converter. Refer to Catalytic Converter Replacement .
1Catalytic Converter Nut (Qty: 8) CAUTION: Refer to Fastener Caution . Tighten 22 N.m (16 lb ft)
2Exhaust Gasket TIP: Replace the gasket with a NEW one.
3Exhaust Manifold Brace Bolt (Qty: 2) Tighten 22 N.m (16 lb ft)
4Exhaust Manifold with Catalytic Converter TIP: If replacing the catalytic converter, transfer the heated oxygen sensor over to the new catalytic converter.
WARNING
Do not use a service jack in locations other than those specified to lift this vehicle. Lifting the vehicle with a jack in those other locations could cause the vehicle to slip off the jack and roll; this could cause injury or death.
WARNING
Refer to Hot Exhaust System Warning .
CAUTION
Refer to Fastener Caution .

Exhaust Manifold with Catalytic Converter Replacement

Removal Procedure

  1. Raise and support the vehicle. Refer to «Lifting and Jacking the Vehicle»(/cadillac/elr/i-2013-2015/remont/hoistjack/#general-information__lifting-and-jacking-the-vehicle) .
  2. Make a cut on the exhaust pipe (1), a distance of 60 mm, from the edge of the muffler flange (a).
  3. If replacing the rear muffler, remove the rear exhaust muffler bracket bolts (1) and lower to the floor.
  4. Loosen the exhaust muffler clamp (1), from the 3-way catalytic converter.
  5. Remove the exhaust pipe from the exhaust isolator (1).
  6. Carefully lower the exhaust pipe (1) from the vehicle.

Installation Procedure

  1. Install the exhaust pipe onto the exhaust isolator (1).
  2. Install the exhaust muffler resonator pipe into the 3-way converter (2) and tighten the clamp to 55 N.m (41 lb ft).
  3. Install the rear exhaust muffler (1) to the rear pipe with a NEW service clamp and tighten the nut (2) to 55 N.m (41 lb ft).
  4. Install the rear exhaust muffler hanger bolts (1) and tighten to 22 N.m (16 lb ft).
  5. Lower the vehicle.
  6. Start the engine and check for exhaust leaks.

Scheme 2

Scheme 2: Catalytic Converter Replacement
Scheme 2: Catalytic Converter Replacement
CalloutComponent Name
WARNING: Do not use a service jack in locations other than those specified to lift this vehicle. Lifting the vehicle with a jack in those other locations could cause the vehicle to slip off the jack and roll; this could cause injury or death. WARNING: Refer to Hot Exhaust System Warning . Preliminary Procedures Raise and support the vehicle. Refer to Lifting and Jacking the Vehicle . Disconnect the heated oxygen sensor. Refer to Heated Oxygen Sensor Replacement - Sensor 2 .
1Catalytic Converter Nut (Qty: 3) CAUTION: Refer to Fastener Caution . Tighten 22 N.m (16 lb ft)
2Exhaust Gasket TIP: Replace the gasket with a NEW one.
3Exhaust Clamp NOTE: If reinstalling the original intermediate pipe, the tail pipe/muffler band clamp (3) should be replaced. Mark the position of the band clamp on the intermediate exhaust pipe. Remove the band clamp by grinding the welds. Install the NEW band clamp on the intermediate pipe. Position the NEW band clamp using the alignment mark created previously. Ensure that the clamp is rotated such that the band portion covers the slot on the intermediate pipe. Tighten 55 N.m (41 lb ft)
4Exhaust Isolator
5Catalytic Converter TIP: If replacing the catalytic converter, transfer the heated oxygen sensor over to the new catalytic converter.
WARNING
Do not use a service jack in locations other than those specified to lift this vehicle. Lifting the vehicle with a jack in those other locations could cause the vehicle to slip off the jack and roll; this could cause injury or death.
WARNING
Refer to Hot Exhaust System Warning .
CAUTION
Refer to Fastener Caution .
NOTE
If reinstalling the original intermediate pipe, the tail pipe/muffler band clamp (3) should be replaced. Mark the position of the band clamp on the intermediate exhaust pipe. Remove the band clamp by grinding the welds. Install the NEW band clamp on the intermediate pipe. Position the NEW band clamp using the alignment mark created previously. Ensure that the clamp is rotated such that the band portion covers the slot on the intermediate pipe.

Catalytic Converter Replacement

Scheme 3

Scheme 3: Exhaust Pipe Heat Shield Replacement (Front)
Scheme 3: Exhaust Pipe Heat Shield Replacement (Front)
CalloutComponent Name
WARNING: Do not use a service jack in locations other than those specified to lift this vehicle. Lifting the vehicle with a jack in those other locations could cause the vehicle to slip off the jack and roll; this could cause injury or death. WARNING: Refer to Hot Exhaust System Warning . Preliminary Procedure Raise and support the vehicle. Refer to Lifting and Jacking the Vehicle .
1Front Exhaust Pipe Heat Shield Nut (Qty: 5) CAUTION: Refer to Fastener Caution . Tighten 9 N.m (80 lb in)
2Front Exhaust Pipe Heat Shield Screw Tighten 9 N.m (80 lb in)
3Front Exhaust Pipe Heat Shield
WARNING
Do not use a service jack in locations other than those specified to lift this vehicle. Lifting the vehicle with a jack in those other locations could cause the vehicle to slip off the jack and roll; this could cause injury or death.
WARNING
Refer to Hot Exhaust System Warning .
CAUTION
Refer to Fastener Caution .

Exhaust Pipe Heat Shield Replacement (Front)

Scheme 4

Scheme 4: Exhaust Pipe Heat Shield Replacement (Center)
Scheme 4: Exhaust Pipe Heat Shield Replacement (Center)
CalloutComponent Name
WARNING: Do not use a service jack in locations other than those specified to lift this vehicle. Lifting the vehicle with a jack in those other locations could cause the vehicle to slip off the jack and roll; this could cause injury or death. WARNING: Refer to Hot Exhaust System Warning . Preliminary Procedures Raise and support the vehicle. Refer to Lifting and Jacking the Vehicle . Lower and reposition the exhaust pipe. Refer to Exhaust Pipe Replacement .
1Center Exhaust Pipe Heat Shield Retainer (Qty: 6) CAUTION: Refer to Fastener Caution . Tighten 9 (80 lb in)
2Center Exhaust Pipe Heat Shield
WARNING
Do not use a service jack in locations other than those specified to lift this vehicle. Lifting the vehicle with a jack in those other locations could cause the vehicle to slip off the jack and roll; this could cause injury or death.
WARNING
Refer to Hot Exhaust System Warning .
CAUTION
Refer to Fastener Caution .

Exhaust Pipe Heat Shield Replacement (Center)

Scheme 5

Scheme 5: Exhaust Pipe Heat Shield Replacement (Rear)
Scheme 5: Exhaust Pipe Heat Shield Replacement (Rear)
CalloutComponent Name
WARNING: Do not use a service jack in locations other than those specified to lift this vehicle. Lifting the vehicle with a jack in those other locations could cause the vehicle to slip off the jack and roll; this could cause injury or death. WARNING: Refer to Hot Exhaust System Warning . Preliminary Procedure Raise and support the vehicle. Refer to Lifting and Jacking the Vehicle .
1Rear Exhaust Pipe Heat Shield Retainer (Qty: 2) CAUTION: Refer to Fastener Caution . Tighten 9 N.m (80 lb in)
2Rear Exhaust Pipe Heat Shield
WARNING
Do not use a service jack in locations other than those specified to lift this vehicle. Lifting the vehicle with a jack in those other locations could cause the vehicle to slip off the jack and roll; this could cause injury or death.
WARNING
Refer to Hot Exhaust System Warning .
CAUTION
Refer to Fastener Caution .

Exhaust Pipe Heat Shield Replacement (Rear)

  1. Raise and support the vehicle. Refer to «Lifting and Jacking the Vehicle»(/cadillac/elr/i-2013-2015/remont/hoistjack/#general-information__lifting-and-jacking-the-vehicle) .
  2. Measure the distance "a" between the muffler and the connection of the exhaust on the new replacement muffler.
  3. Transfer the measurement "a" to the exhaust pipe (1).
  4. Separate the muffler at the determined cut line with a suitable tool.
  5. Remove the exhaust muffler hanger bracket.
  1. Install the rear exhaust muffler clamp onto the rear cut exhaust pipe.
  2. Install the rear muffler exhaust hanger bracket and tighten the bolts to 22 N.m (16 lb ft).
  3. Install the rear exhaust muffler (1) to the rear pipe and tighten the clamp nut (2) to 55 N.m (41 lb ft).
  4. Lower the vehicle.
  5. Start the engine and check for exhaust leaks.

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

  1. Exhaust manifold with Catalytic Converter
  2. Exhaust pipes
  3. Catalytic converter
  4. Exhaust hangers
  5. Exhaust heat shields
  6. Exhaust isolators and rods
  7. Exhaust muffler
  8. Exhaust resonator, if equipped
  9. Exhaust tail pipe, if equipped

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 added to the engine exhaust system in order 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

  1. Platium (Pt)
  2. Palladium (Pd)
  3. Rhodium (Rh)

The catalyst in the 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.

Special Tools

Illustration Tool Number/Description EN-35314-A J-35314-A Exhaust Back Pressure Gauge CH-6179 KM-6179 Heated Oxygen Sensor Remover/Installer CH-6614 MKM-6614 83 95 667 Chain-type Pipe Cutter

Scheme 6

Scheme 6: Special Tools
Scheme 6: Special Tools