On this page
When your exhaust starts hissing, ticking or roaring, there is a leak somewhere between the engine and the tailpipe. Route 66 Auto Repair in Upland finds that leak with the engine running, shows you a photo of it, and writes an estimate before any repair. Our ASE-certified technicians repair the joint, gasket or section that failed, and they tell you plainly when a louder exhaust can wait.
What are the signs of an exhaust leak?
- A puffing or hissing sound that speeds up with engine speed
- Ticking at cold start that quiets once the engine warms
- A deeper, louder note under acceleration
- An exhaust smell in the cabin at stoplights
- Black soot marks around a joint or flange
- A check engine light for a lean mixture after a noise appeared
How do we find an exhaust leak?
Leaks hide. A pinhole on top of a pipe is invisible from below, and a cold tick may seal once the metal expands. So we start cold when we can, listen along the run, and look for soot trails where gas has escaped for a while.
For stubborn cases we check again after a short run, when the metal has grown, and at a steady higher idle, where a hidden leak often gets louder. Our separate exhaust leak inspection covers the test by itself when you only want answers.
What does the repair usually involve?
Most leaks fall into one of three fixes. A blown flange gasket or donut seal gets new gaskets and new bolts, since the old ones are usually rusted. A leaking slip joint or clamp gets a fresh clamp and a clean seal. A pipe with a hole in weak metal gets a replacement section, covered on our exhaust pipe replacement page. Leaks at the engine end are their own job, explained under exhaust manifold repair. Your written estimate shows every step.
Our exhaust leak repair process
Step 1: Listen cold and warm
We reproduce the noise with the engine cold and again warm, following it along the run to the leak.
Step 2: Check the metal around it
We tap the area to decide whether a gasket, clamp or new section is the lasting fix.
Step 3: Photo and estimate
You see the leak and approve the repair before we start.
Step 4: Seal and verify
We repair the joint or section, run the engine to confirm the seal, and road-test the car.
What's included in an exhaust leak repair
Included on the work order
- 01Engine-running leak location
- 02Cold and warm listening checks
- 03New gaskets and fasteners at opened joints
- 04Oxygen sensor wiring check near the leak
- 05Post-repair seal check
- 06Road test for noise
Does your exhaust leak need fixing now?
Need now: call
- Any smell inside the car
- A leak under the cabin floor or near the front
- A leak scorching wiring or a nearby hose
Need later: book
- A small leak at the rear, well behind the cabin
- A faint tick with no smell and no warning light
How pricing and timing work
A gasket swap and a new pipe section are priced very differently, and rusted bolts can add time, so we quote after we see the leak. AAA members get 10% off parts and labor, up to $75. Many leak repairs are same-day when the board allows; call before you drive over.
Frequently asked questions
Can an exhaust leak cause a check engine light?
Yes. A leak ahead of an oxygen sensor can pull in outside air, and the sensor reads it as a lean mixture. Fixing the leak often clears the cause, and we recheck the codes afterward.
Will exhaust tape or paste fix my leak?
It may quiet a small leak for a short time on solid pipe. It will not hold on thin metal or at hot joints near the engine. We would rather show you the leak and let you decide with a photo in hand.
Why did my exhaust get loud overnight?
Rust works slowly and then lets go. A thin spot or a tired gasket can blow open on a cold start. It is worth a lift check soon, mainly to make sure the leak is not near the cabin.