Ticking sound when accelerating

2006BUICKLUCERNE

MEMBER
2006 BUICK LUCERNE
4.6L
V8
2WD
AUTOMATIC
105,000 MILES

Hi, I've posted about my issue before but now I have audio.

Car listed above CXS model, 4.6L Northstar V8.

Problem: My car makes a ticking sound when accelerating. It appears to be coming from the engine. The ticking doesn't occur at idle. The sound doesn't start until I drive the car for more than 30 minutes. The sound goes away as soon as I let go of the gas peddle. For some reason when I put on the cruise control and the car accelerates at the same RPM, the sound is gone. Maybe that's a coincidence but 90% of the time cruise control is on the noise immediately goes away, even when it's at the same RPM. The noise occurs at any RPM as soon as I press the gas.

More info: I've kept up on oil changes. I'm using 93 Octane gas. I've driven the car normally. I don't notice any mechanical side effects of the noise. I tried a Seafoam treatment and nothing changed. No check engine light.

Links:
[Revving](https://youtu.be/iz7x__kaoMs)

[Driving normally Loudest](https://youtu.be/E1Kite6mg1s)

[Hard acceleration](https://youtu.be/WS1wA5FSd5k)

Don't mind the speed limited to 80 message, ride height sensor is out. The sound is really obvious in the one where I'm driving down the street.

1 Reply

CARADIODOC

MECHANIC
33,742 POSTS

I can't hear the noise well enough, but from what you described, an exhaust leak is the best suspect. This usually occurs where the exhaust manifold bolts to the engine block, but it can also come from where the exhaust pipe is attached to the manifold. You can often verify this by doing a "brake stand". Shift into "drive", hold the brakes applied, then raise engine speed. When the engine is loaded that way, the exhaust leak will usually open up and you'll hear the ticking noise. If necessary, have a helper do that while you stand next to the engine with the hood open.