You’ve got questions. We’ve got the answers—the Summit Racing tech department tackles your automotive-related conundrums. This week, we’re examining why new headers can cause strange noises from your engine.
Q: I have a third-gen. Camaro that is well taken care of. I recently added a set of headers, and I’ve been hearing funny sounds from underneath the car ever since.
I went back to the shop that installed the headers and they determined that the headers were not leaking. A friend of mine thought maybe the engine was experiencing detonation and suggested I swap out the Hypertech chip for the stop chip. I still have the problem! The only other modification I made to the car is a Flowmaster muffler. I am using 92-octane gasoline. The headers, muffler, and chip are all CARB legal. Any ideas?
A: The noise you are hearing is likely the normal “ringing” sound a healthy engine with headers makes. This is due to the energy of the exhaust wave pulse hitting the header tube, causing it to vibrate. You may hear that noise as an engine ping. You won’t hear that sound with stock exhaust manifolds. Due to their extra mass, manifolds vibrate at a much lower frequency and absorb much of the exhaust gas energy.
Still, engine detonation is a serious problem and can result in severe engine damage. Detonation is the result of our air/fuel mixture being burned too rapidly around Top Dead Center, when the leverage ratio between the connecting rods and crankshaft is poor. That rapid air/fuel burn creates excessive cylinder pressure, which in turn makes shock waves that can damage or destroy an engine.
The bottom line is if detonation is occurring, your compression ratio is too high for the fuel you are using. That doesn’t seem likely in your case, but a quick way to find out is to add some octane booster to your gas and see if the noise goes away. If it doesn’t, you need to lower the compression ratio.
Really? You’re going to tell him to drop the compression on a car that’s mostly stock? How about checking ignition timing and drop it back a degree or 2 and see if the problem persists. Very easy with a motor with a distributor like his car should definitely be equipped with
Jeffrey, the compression comment wasn’t directed at this vehicle in particular. It was just a general comment regarding detonation and pinging. With this particular vehicle, we’re focused on the new headers. Certainly should have clearer. Our apologies.
“Detonation is the result of our air/fuel mixture being burned too rapidly around Top Dead Center, when the leverage ratio between the connecting rods and crankshaft is poor.”
Seriously? Detonation is a result of the fuel mixture going off at the wrong time in the timing cycle. Since when does installing a set of headers raise an engines compression ratio?
Octane Booster is garbage
Take all the oil out, pour it on a chicken. Cut the chickens head off and pour the blood into your overflow reservoir. Chant “mopar” for 2 minutes. Put your keys under your pillow and go to sleep. When you wake up, go buy a jeep. Problem solved.
Lol like the way you think Fred! Lol TOO FUNNY!!!!!!!
Did you check for clearance? Because headers are so bloody huge, they’re probably touching somewhere and that sound could even be a vibration against another part. Never know.
If the Pinging goes away with the octane booster the compression is to high. if it doesn’t go away it is the header noise. ALWAYS specify good octane booster like 104+ please no garbage.
Right! Mr. Fuller has the last paragraph backwards.
If we’re dealing with detonation and engine pinging (probably not the case with this specific vehicle) and the pinging doesn’t go away after adding octane boost, you need to scale back the compression.
try looking at the air/fuel ratio maybe when you put the headers on. The ratio could have gone to the lean side causing it to ping
The stock motor is 9.3:1 you opened up the flow out the exhaust and the 02 sensor was be not adjusting right making the car run lean . Need to find out what the air fuel is at idle and wide open throttle, she is 29 yr old the injectors are probably dirty make every think off , need to do a full tune up , spark, timing , fuel ,
Headers are a pain in the ass,always were and always will be.