An exhaust leak is any opening that lets combustion gas escape before the tailpipe, and it can be a cracked manifold, a failed gasket, a split flex pipe or a rusted joint. AutoTech Clinic finds and repairs exhaust leaks at our shop on Michigan Ave in Dearborn.
A leak ahead of the oxygen sensor matters more than the noise suggests. Extra air entering the stream makes the sensor read lean, the computer adds fuel to compensate, and you lose fuel economy and risk damaging the catalytic converter.
- How Long
- From about 1 hour for a joint to most of a day for a manifold.
- Same Day
- Usually finished the same day.
- Vehicles
- Foreign and domestic, cars through trucks.
Signs You Need Exhaust Leak Repair
- A ticking or tapping from the engine that is loudest when cold
- A deep puffing or hissing that rises with engine speed
- An exhaust smell inside the cabin, especially with the windows down
- A check engine light with lean mixture or oxygen sensor codes
- Black soot marks around a manifold flange or pipe joint
- A loss of fuel economy with no change in your driving
What We Do
- 01
Locate the Leak
We run the engine on a lift and locate escaping gas by sound and feel, and we use a smoke test where the leak is hard to pin down.
- 02
Separate Manifold From Pipe
A ticking that is loudest on a cold start is a classic cracked manifold or blown manifold gasket, and that is a different job from a leak further back.
- 03
Check What the Leak Is Doing
We read fuel trims and oxygen sensor data to see whether the leak is upsetting the engine management, which affects how urgent the repair is.
- 04
Repair Correctly
We weld, replace gaskets with new hardware, or replace the failed section. We do not use exhaust paste on a joint that should be sealed properly.
- 05
Verify and Clear
After the repair we confirm the leak is gone, clear any codes and check that fuel trims return to normal.
A Tick That Goes Away When Warm
A metallic ticking on a cold start that fades after a few minutes is the signature of a cracked exhaust manifold or a failed manifold gasket. The metal is cold and the crack is open, and as everything expands the gap closes and the noise reduces.
People often mistake it for a lifter or an injector. The difference is that an exhaust leak tick is sharper and comes from the manifold area, and it usually gets quieter as the engine warms, which an internal engine noise rarely does.
Why a Small Leak Costs You Fuel
The upstream oxygen sensor measures the oxygen content of the exhaust to set the fuel mixture. A leak before that sensor pulls fresh air in during the pressure pulses, so the sensor sees extra oxygen and reports a lean mixture.
The computer responds by adding fuel that the engine did not need. You lose economy, the mixture runs genuinely rich, and over time that overheats and damages the catalytic converter. Fixing a small leak early avoids a much larger bill.
What Affects the Cost
We quote your vehicle specifically after inspecting it, because these are the things that move the number up or down:
- Where the leak is, since a manifold is far more work than a rear joint
- Broken or seized manifold studs, which are common and add significant time
- Whether a gasket, a flex pipe or a full section is required
- Access on transverse engines where the rear manifold is against the firewall
- Oxygen sensors that have to be removed and may seize in place
Call (313) 277-7200 with your year, make and model and we will tell you what to expect before you come in.
Why AutoTech Clinic
AAA Approved
An inspected facility that has to meet AAA standards for equipment and training.
Photos First
You see what we found and approve the price before anything is taken apart.
Same-Day Service
Parts on hand for the vehicles we see most, so you are not waiting on a delivery.