My 97 4.6 has a noticeable tick that sounds like an exhaust leak to me. It comes from the passenger side wheel well for a minute or so after cold startup. I read that it could be from the oil filter so I've switched to a Purolator and it still does it. Any suggestions on things I can check? I don't see any place where the manifold is leaking. It only has 75k miles. Runs good but the idle is a little bit rough sometimes.

 

You need to check your spark plugs, one may be coming loose. Torque them to 28 ft/lb.

 

I changed the plugs a couple weeks ago and I used a torque wrench to install the new ones at said torque. It had the ticking before and after. And none of my old plugs were loose.

 

Check the heat shields on your cats. I ended up removing the shields on my 97 4.6 cats because they were ticking, rattling, until they warmed up and it did sound like it was coming from the wheel well. The pcv can tick as well.

 

Ok I'll look into those as well. I should mention the tick barely noticeable unless you are standing on the passenger side. It isn't much louder than the injectors on the Ecoboost I had but it is noticeably louder on the passenger side vs the driver side so I don't think it's injectors.

 

what oil filter you running?

 

He said a Purolator.

 

Yea I just bought the truck about 3 weeks ago so I'm not sure what the PO had on there. I had Jiffy Lube change the oil the first time because I wasn't going to have time. I found out later on that their filter is made by Fram. I only ran it a week before I switched to Purolator but I noticed the tick before the oil change too.

 

I'm leaning toward it being an exhaust leak now. I drove it yesterday before the sound went away and it sounded more and more like an exhaust leak as I drove. It still goes away after about a minute or two. The guys at the muffler shop didn't seem too optimistic about being able to replace my manifolds.