Spiral534

Hey everyone! I have searched for some time now on this forum and others and cannot quite find an answer that best fits the following description. I was hoping to gain some clarity on this and think this is one of the better forums out there for answers.

For the past few months I have been experiencing this intermittent tick/click from the back/bottom of the engine (4.6L 2v). It starts immediately after a cold start and remains until the engine gets to operating temp (middle of temp gauge). It is a definitely the sound of metal expanding/contracting. It does not increase the higher the RPM's and does not get louder under any load. Every 15-30 seconds it sounds like someone taps the midpipe with the ring on their finger.

So I have checked the manifold bolts on both sides and they are tight, no cracks, then checked the midpipe with a long screwdriver used as a stethoscope and pinpointed the tick/click coming from the driver side midpipe (stock h pipe).

I changed the midpipe and catback as I was going to anyway and put on a MAC O/R H Pipe with a Magnaflow Street Catback.

The sound is still there but not quite as prominent. Maybe about 2/3 of the volume it was prior. The stock h did not rattle nor did anything come out of it after I took it out and shook it for noises.

What am I missing? I am not thinking plugs, timing, or relays as it will make the sound for a bit after turning the car off - until it has cooled down.

Any input would be greatly appreciated. Thanks!

Spiral534

Bump.

Urambo Tauro

Heat shields?

Spiral534

Thank you for the reply. I really thought they were the heat shields or something on the stock mid pipe because the sound came from around the front cats heat shields. Replaced the entire mid with an O/R pipe and the sound is still there.

It's probably nothing to do with internal engine parts since it makes the sound with the car off? Nothing electrical because it makes the sound while off and negative terminal disconnect?

Maybe manifold itself and the down pipe is funneling the sound?? Thanks for any thoughts everyone.

Z28KLR

Exhaust manifold gasket, maybe?

Spiral534

Thanks. Yea, you are in the same ballpark as in my head - manifold area. Probably is the gasket. The only way to check the gasket is to take the manifold off, correct?

Spiral534

Anyone have any recommendations for what to check for with the manifold in place? As far as checking the gasket for leaks...