So, I picked up a 1996 F350 plow truck with 460 gas motor, 4x4 and automatic trans from a guy last year. I knew it had an exhaust leak so I was planning to fix it. I just got around to doing it spurred on by cooking some spark plug wires due to the hot exhaust gasses baking them. What I found is an absolute nightmare. On the passenger side front exhaust port (cylinder 1) the stud was missing. I figured it had broken off like many others I've read about. Turns out that the whole exhaust port is cracked around the plug for the older style smog gear and is missing considerable material. The former owner filled it with JB Weld!!!

To make a long story a little shorter, now I've got to replace the passenger side head and the passenger side exhaust manifold. So, I started to pull things apart. I'm stuck on the EGR smog stuff. The metal pipes that come off the back of the exhaust manifolds are rusted on there. Plus there's no access to really get any leverage on them.

I'm a bit puzzled as to what to do next. I need to get the truck back up and running asap to plow snow. Here are my options as best I can come up with:
1. Pull the motor and work on it outside of the truck hack up the EGR smog stuff and replace all damaged stuff (likely very expensive)
2. Light the whole thing on fire (would provide serious stress relief)
3. Remove all the EGR smog stuff and plug the holes
4. Do a carb swap

 

Does this truck have to pass a sniffer test? If not then the whole smog(air injection) system can be removed. Note that the EGR system is separate and consists of just the EGR valve/sensor combo which is attached to the intake drivers side rear and a single tube connecting to the exhaust manifiold/header... copper tube in the pic below. This system must remain connected and functional or you will get codes and a check engine light. All other tubes connected to the exhaust will be part of the Smog system and can be removed, but the TAB/TAD solenoids near the coil have to remain electrically connected and any vacuum lines in the system capped.

 

The truck is registered in CT and will need to pass an emissions test each time I renew the registration which is every two years. It just passed a few months ago even with some exhaust leaks. In CT it's very hard to fail an emissions test by way of the sniffer. However, not having a catalytic converter or having a Check Engine Light is an automatic fail. I've passed emission tests with old carbed V8s with mild exhaust leaks and a gutted cat. What I'm trying to say is that as long as I have the cat on there and no CEL, I should pass.

What I think I'm hearing from you is that I can remove the air injection lines, plug the holes, remind the TAB & TAD lines, leave the connectors hooked up but cap the vac lines. Then I just need to have the EGR valve/sensor functioning with the large metal hose going to the driver side exhaust manifold and I should be good to go with no CEL. Do I have that right? Thanks very much for the input. You're a life saver!

Oh, one more question.... I'll need to replace both exhaust manifolds. Without breaking the bank, what are my options? I've seen Dorman makes manifolds but I don't know if they'll last. Would a cheap header be a better option? Maybe some used old 460 manifolds off another vehicle?

 

Cheap headers are just that, CHEAP.

As for Dorman manifolds, I have had bad luck with 351 ones. Replace on a year under warranty. Not sure if the 460 ones are as bad.

I did away with my manifolds because the stock Ford ones were known for cracking.

I put on the Banks Torque Tubes(NOT CHEAP) but they are now 13 years old and I have about 50k on them without a hiccup(other than the crappy NON stainless hardware supplied with them)

 

I agree. I put a set of Dorman manifolds on my F150 with 5.0 to replace some cracked cheap shorty headers. After a year they were flaking like hell. They hadn't leaked yet but I would be lucky to get another year or two out of them. I sold the truck though.

Here's what I'm thinking.... Since I can't blow $1000 on the good Banks stuff, if I pick up a set of OEM manifolds like these : http://www.ebay.com/itm/Ford-460-429-Exhaust-Manifolds-Lincoln-Mercury-/141170175918?pt=Motors_Car_Truck_Parts_Accessories&hash=item20de65efae&vxp=mtrAnd then weld the EGR feed tube onto the collector pipe below the manifold flange and run a pipe the same way as in the pic a few posts above, then I would have a quality manifold minus smog gear with working EGR for a few hundred bucks. What do you think?

 

You will need to find '88 and later manifolds. 7.5L EFI heads have different port setups for the intake and exhaust versus the older carb'ed heads.

 

Correct. And cars used different manifolds than trucks as well(but you re not going to find EFI car manifolds)

 

Picked up a bunch of parts from a 96 F350 w/460 part out the other day. I got an entire motor with 177k on it. The good news is the exhaust manifolds are in excellent shape. They must have been replaced recently. The bad news is that the rest of the motor is very rusty and the heads are not usable. I've still got to find a good set of F3TE heads. If anyone knows of a set for sale in good working order, please let me know!

So, here's my new plan....
1. Remove the EGR pipe to the exhaust manifold, put a block off plate between the EGR solenoid and the intake, leave the vacuum line and electrical connector hooked up so the solenoid can still operate and the ECU still sees it working to avoid a CEL.
2. Do the same thing with the TAB and TAD solenoids. Remove the lines, plug the vacuum nipples, leave the electrical connections hooked up.
3. Remove the smog pump and lines and plug the holes in the exhaust manifolds.

Does anyone see any issues with this strategy? I need to pass an emissions test in CT but as long as I have a catalytic converter installed and there is no CEL, I will pass.

 

Updating for some good progress...

I got the motor back together and it's in the truck. It's 90% hooked up and about ready for some oil, coolant and a test fire.

I've got just about everything hooked up but the vacuum lines that run to the two solenoids behind the coil.

I deleted the Thermactor pump, hoses, Air-Diverter valve and Air-Bypass valve. I plugged the holes in the exhaust manifolds where the lines used to come out of.

I retained the EGR valve. I had to get a new EGR hose and fitting that connects the hose to the exhaust manifold which was about $70. Ouch!

Anyway, the TAB and TAD solenoids are still in place. I had done some reading up on this site and heard that leaving them in place with electrical connectors plugged in was the way to go to avoid a CEL. I capped the nipples on the solenoids and capped the nipples on the manifold T.

Now, here's my question.... The EGR valve has a green vacuum line coming off of it. This runs to either the TAB or TAD solenoid, I don't recall which. Where do I hook this green vacuum line up to that comes off the EGR valve now that the rest of the TAB/TAD system is capped?

I'm guessing that depending on how much vacuum the EGR valve sees, it is going to open and close as needed. I want this to still function properly.

 

No.. the EGR vacuum is regulated by a 3rd solenoid called the EVR and it is usually mounted on the same bracket with the TAB and TAD.

 

Ahhhh, right! Just searched for some parts diagrams and now I see that. So the green line goes to the EGV and then the white line goes from the EGV to the vacuum reservoir?

EDIT: I just went out to my truck and what was throwing me off is that I have 2 solenoids on the bracket behind the coil. I thought that they were TAB and TAD but after taking a closer look, one is EGV and the other is either a TAB or TAD. Not sure why my 96 F350 doesn't have both a TAB and TAD...???

 

On later trucks the TAB and TAD valves were combined into a single unit so I don't know for certainty but it's possible the TAB and TAD solenoids also got combined into a single unit, and of that is the case you would only find 2 solenoids with one of them being the EVR solenoid.

 

Thank you sir! That is exactly what is going on under my hood. Got everything hooked up and got her running tonight! The motor sounds great.

I've got two left over parts that I could use some help identifying so I can get them installed. Here are some pics:
The first is a hard plastic hose that I believe goes onto the back of the throttle body and then to the MAP sensor. I wasn't positive about this so I capped the nipple on the back of the throttle body for now.

The second is a bracket that I believe bolts to the intake manifold but I'm not sure exactly where and I'm not sure what lines or wires are supposed to be retained by the plastic clip.


Lastly, the engine is running very rough upon initial startup as if it's missing and then it smooths out and runs nicely but it is also idling high. I don't have a tach so I don't know exactly how high but I'd guess around 1750-2000 rpm. I'm thinking that my first step is to look for vacuum leaks. I've also got a CEL that I have to pull the codes for. I'm guessing that the hard black plastic hose is for the MAP sensor and that not being hooked up could be causing my rough start and idling problems. I'll get back at it tomorrow and see.

 

Out of curiosity, why did you have to replace the passenger side head? Surely you could drill the broken bolt out? I asked because my truck ('97 F350 with 351W) has a broken stud on #5. I was thinking of letting a shop do it since I don't see doing it myself.

Hope you replace the oil pan at the same time, they get rusty after a while, too.

 

The exhaust port had rotted away on the head.

The oil pan was done on the truck a couple years ago.

I'd recommend having a machine shop remove the broken stud. Those guys are magic at that stuff!