Help with popping noise

[Cup Of Java]

Last week my 2000 Expedition 5.4Liter was at a stop light and began running a little rough. A popping noise started not long afterwords, I was only a mile from home so I pulled in the driveway and openeded the hood. I checked for any plugs loose or ejected but didn't find any. I recently had the plugs and coils changed about a year ago.

It almost sounds like a leaky manifold gasket but sometimes it goes quiet and sometimes makes a hissing sound when you shut the engine off.

Any ideas?

 

[panda24619]

could be cracked exhaust manifolds. hard to check, but go into your fender well and lift up the inner fender wall. its just rubber. and see if they are cracked. both mine were. they were right in the middle. and take it in to do. cause most likely they will need to drill and tap new bolts into place.

 

[Cup Of Java]

I didn't see any cracks (could be a hairline) but it definitely has two bolts in the back that were missing, looks like I will be taking it to the muffler shop this week.

Thanks!

 

[toms89]

I didn't see any cracks (could be a hairline) but it definitely has two bolts in the back that were missing, looks like I will be taking it to the muffler shop this week.

Thanks!

A minor exhaust leak should not make it run rough though you still likely have an exhaust leak if some bolts are missing. Hissing sounds like a vacuum leak unless its your a/c lines equalizing but thats normal. Maybe egr system?!

 

[carlosshane1477]

Have you checked if there is a leak, and also check the fuel, OK. Carburetor? that would be the cause of the popping noise. If you have more Ford repair questions just take a look at the link.

 

[Cup Of Java]

Thanks for the replies.

I had two estimates for repairing the exhaust manifold. Both were just over $1000. I went ahead and took it off and replaced the gaskets and bolts myself. All bolts came out easily with stud extractor.

However, I also had the spark plug problem. This one was the #3 plug but it didn't damage the coil, after removing the coil the spark plug was removed with a magnet. I purchased the Dorman repair kit and hope to have it fixed this weekend.

It hasn't been a bad truck, I have 168,000 miles on it and plan on trading it in soon.

Thanks for your help.