01 F150 exhaust leak...I think

Status
Not open for further replies.
Joined
May 12, 2003
Messages
7,829
Location
Oklahoma
My truck started developing a slight exhaust leak sound a month ago. Thought it was the tell-tale beginning sound of the dreaded spitting spark plug. Replaced the plugs, sound still there, but truck needed plugs anyway. It's really noticable when it's cold....guess when metal heats up, it closes the gap. Mechanic friend tried this, put the truck in gear, hold the brake, give it gas. Said if the exhaust manifold is cracked, we'd hear it. Nothing. Neighbor crawled under the truck and said it was coming from the exhaust donut. Have any of ya'll had this problem? Those bolts are just totally rusted and I know I won't be able to tighten them. How hard is it to replace the passenger side exhaust manifold?
 
My son was recently given a 2002 F-250 with the 5.4 liter engine. His truck had very similar symptoms to what you are describing. It turned out that there was a leak at the connection where the exhaust manifold joins the exhaust down pipe. Both bolts that hold the fitting together were missing and there was a big exhaust leak on that side. I fixed that leak, but there was still another leak. Turned out that the exhaust manifold was also cracked on the passenger side. It was worse when cold and improved as the parts warmed up and expanded. The mechanic claimed that this problem was quite common with the 5.4 liter v-8. We paid to have that job done and I am glad that we did. The mechanic had to cut the exhaust manifolds off in pieces with a torch. Then he had to wrestle with getting all the rusted studs out of the head. Took him two full days to do both sides. Now the truck sounds and drives great. Hopefully the repairs will last a while.

Good luck.
 
A few years ago my 2002 F-150 4.6 developed what I thought was a leaking exhaust manifold, same symptoms as yours. Turned out the EGR feed tube from the exhaust had rotted. Had that replaced and she's been quiet ever since.

Whimsey
 
As Sluggo0018 said, this is a common problem.

Modern engine mounts are more compliant than ever for less vibration transfer, so the exhaust gets stressed more than ever, mainly at the manifold to Y pipe joints. Then add road salt, and there's little left to work with.

And yes, even if the manifold itself is OK, getting the Y pipe off often involves busting the studs, if there's any studs left to bust. Besides being rusted away they are rock hard due to heat cycling. Busted stud removal is often more practical at the machine shop than under the truck.

As for how hard, I'll defer to someone who has done that job on your type of vehicle. Just a warning, often removal of the manifold involves breaking a few of the studs off the head. This can run up a bill quickly, so ask ahead of time what the per-stud charges are.

EDIT: Good point, Whimsey. Replacing the EGR feed is usually a much cheaper job.
 
Last edited:
Appreciate the reply's....could be either....manifold or at the connection. Truck has only 72K miles on it, what kind of mileage are we talking about for those that had to replace the manifold? I'm thinking that manifold is still too "new" to develope the common Ford exhaust crack and could be the connection leak or maybe it could be the EGR feed location.
 
Manifold studs like to break on these too. Usually in the least convenient place possible.
 
Originally Posted By: Schmoe
Truck has only 72K miles on it, what kind of mileage are we talking about for those that had to replace the manifold? I'm thinking that manifold is still too "new" to develope the common Ford exhaust crack and could be the connection leak or maybe it could be the EGR feed location.


As far as my sons truck is concerned, it had roughly 80,000 miles at the time of the manifold replacement and exhaust repairs. I also changed out the muffler and tail pipe at the same time. The muffler was like Swiss cheese.
 
Thanks. Got some good recon to get under it and start looking or feeling around. It just about goes away when it's fully warmed up.
 
I have an '03 with the 5.4 and on mine the manifold gasket went bad on the passenger side around 95k miles. Went to NAPA and they had the "improved" version which means to me it was a cost cutting measure by Ford.

If you do the work yourself like I did all I can say is presoak the studs with penetrating oil for days and run the engine through some heat cycles. I found out the hard way and broke 3 bolts out of 8. Went and got a stud remover and broke 1 stud (rear most on cylinder 8) a second time and ended up taking it to a muffler shop. $140 later it was all done
smile.gif
.

If you have the funds I would look into exhaust studs from ARP. They are stainless so if you ever have to remove the manifold again then it should be a lot easier.
 
Originally Posted By: SVTCobra
I have an '03 with the 5.4 ... all I can say is presoak the studs with penetrating oil for days and run the engine through some heat cycles.


+1 ...this works ...liquid wrench is your freind. apply each day and it will migrate into the stud and release the corrosion. Also works well on other rusted fasteners with only one caveat. Exposed rusty threads with liquid wrench applied should be wire brushed before removing a nut. Otherwise The rusty mess can bind in the threads and seize. Another trick is to work a binding fastener out and back in and gradually out.

My 02 F150 has had the manifold leak for more than 100k miles and it always quiets up once it is warm. Have over 180K on it now with no plans to fix it. The EGR hose is another one too I have fixed. Good info by all here :)
 
Last edited:
With that low of mileage on a 15+ year old truck don't think that the rusted/cracked manifold isn't your problem... Believe it or not but I'd buy a 15 year old vehicle with 100k miles before I'd buy one with 30k miles... the setting and short trips kills them faster than anything. My 01 F150 just turned 226k miles and runs like a top! Yes the manifold leaks because the studs are mostly rusted off but ya get used to it.. When I put the new motor in, I'll fix the studs and manifold but I'm not even attempting it in the truck!
 
I gotcha racin....almost all of those miles are long trips and pulling either a boat or seadoo. With that Lariat package and all comforts, plus a fiberglass bed cover, it's the family's vacation cruiser, gas milage be )amned!!! I don't take it out for short trips...plus, that thing is thirsty. The sound doesn't bother me so much as a youtube vid I saw that some guy said he didn't fix the leak for quite some time, but when he did, the acid nature of the exhaust along with the aluminum heads, he had some bad etching on the exhaust ports and had to do some cold welding on it to fill in the gaps. That worries me a little.
 
Status
Not open for further replies.
Back
Top