Class C 1994 with e350 chassis exhaust manifold glowing red

[jcb47769]

Has anyone seen anything like this?


It's not a clogged catalytic converter, and I've replaced the PCV valve recently.

Exhaust manifold glows under heavy load (hills and over 55)

I found a small exhaust leak in the manifold gasket, thinking about sealing it with exhaust repair epoxy instead of risking the rusty bolts holding on the manifold.

[DiskDoctr]

460 ignition system (as I mentioned earlier) tends to burn out, causing misfires, dumps unburnt fuel into the exhaust, clogs up the catalytic converter.

You won't regret replacing the parts.

I spent extensive time working on and solving 1991 460 problems. All is good now for some time. Lots more power, too 😉

[CharlesinGA]

jcb47769 wrote:
Made a little progress, EGR reconnected, now manifolds are ok but exhaust pipe just after is glowing red. I checked to see if the muffler was blocked and i dont think so. I'm replacing the o2 sensor just on principle, it's rusty and I'm keeping this class C for a while 🙂

Anyone know how to do the reset on the computer that make it have to relearn usage and adjust gas consumption?

Ford EEC IV system, its not that sophisticated, just change the parts and drive it. Nothing for it to relearn. EEC IV is a very good system but there are things you need to pay attention to. Most have already been mentioned.

My experience is with smaller engines wiht EEC IV and not the 460 but the systems all work the same.

Find out what year the chassis is, and buy the FACTORY manuals off of Ebay, they are worth their weight in gold.

Charles

[jcb47769]

Made a little progress, EGR reconnected, now manifolds are ok but exhaust pipe just after is glowing red. I checked to see if the muffler was blocked and i dont think so. I'm replacing the o2 sensor just on principle, it's rusty and I'm keeping this class C for a while 🙂

Anyone know how to do the reset on the computer that make it have to relearn usage and adjust gas consumption?

[Chum_lee]

jcb47769 wrote:
No CEL but EGR is disconnected at the moment. It was glowing before I disconnected it though. Do 1994 e350s get check engine light though?

The primary purpose of EGR is to lower combustion chamber temperatures which reduces NOx emissions. The end result of adding EGR is lower exhaust temperatures. It's quite common for EGR valves to plug up.

Excessive exhaust temperatures is one reason exhaust manifolds and studs break/crack.

Chum lee

[PaulJ2]

Red hot manifolds mean either ********/late ignition timing or improper spark advance operation. Would also likely be down on power.
Make sure initial timing is set to specs with jumper wire disconnect if required. Some require this, some not.

[j-d]

Check the Date on the Door Jamb Label provided by FORD. If it's later than AUG/SEP 1992 it's a 1993 chassis. Could make a difference in troubleshooting and parts.

According to RockAuto.com a 1992 has O2 sensors. Or SensoR. It only shows an Upstream (of the Converter) sensor. Some three-wire and some four-wire. That would mean it has some form of fuel mixture control.

Is this 460 TBI (Throttle Body Injection, Two Injectors in a carburetor-looking body) or MPI (Multi Port, Eight Injectors)?

Injectors are pretty dependable. This is above my pay grade, but I wonder if a clogged injector would not be detected as a fault, but run that area lean. And maybe even the O2 sensor report lean and richen via the rest of the injectors.

[jcb47769]

The manifold leak is on the opposite side (passenger side) from the large leak (fixed now) where I was battling the broken stud. The engine is EFI, could the computer be adjusting lean based on bad inputs? Or does that not happen on 1993 (i think I'm 1993 chassis)?

[j-d]

Is this the side where you fixed the broken crossover pipe stud? I wonder if the scorched wiring you found was at least partly the hot manifold.

From what I've read, excess unburned gasoline will overheat the catalytic converter, not the exhaust manifold. I think the hot manifold is a result of a LEAN condition as others have mentioned.

Older 460's got "EGR Plates" added, between the Intake Manifold and the Four Barrel Carburetor. This provided mounting for the EGR valve and the needed port back into the engine. The thick carburetor insulator gasket was on top and there was a thin gasket under. On ours, the Plate rusted to the mounting studs and the thin gasket blew out underneath. Lean condition. Ran better with both gaskets new and the connections cleaned up so tightening the nuts at the carburetor tightened the whole stack.

I also read that "older" 460's developed intake manifold gasket leaks. Again, lean condition. You may be able to spray carb cleaner, even WD-40, around the intake areas with engine running. If it "finds" an intake leak, you'll hear it in how it runs.

[Home_Skillet]

I would also check the fuel pressure regulator.
The would leak fuel internally, allowing raw fuel into the vacuum hose. Which then goes into the engine.

[DiskDoctr]

FIL has a 1991. Check your plugs for weak spark, allowing unburnt fuel.

Replacing your rotor, cap, plugs and wires and ignition coil can breath quite a bit of power and life back into these 460 gassers.

[Home_Skillet]

Llibnmap wrote:
IMO if mainfolds are glowing red it's running way too rich! Either that or the exhaust is clogged. Just my thinking

Bill

100% correct.

[jcb47769]

No CEL but EGR is disconnected at the moment. It was glowing before I disconnected it though. Do 1994 e350s get check engine light though?

[ScottG]

Llibnmap wrote:
IMO if mainfolds are glowing red it's running way too rich! Either that or the exhaust is clogged. Just my thinking

Bill

On a gas eng it would indicate a lean condition.

If it has been a long time since the 02 sensor has been replaced, I would do so.
They get lazy and cause poor performance way before they're so bad it triggers a CEL.

[Edd505]

That have a heat riser by chance? If it does it's sticking.