Ok, I have an engine problem, I think it might be an easy fix 1997 Expedition

[TheSiege]

It basically feels like the truck is misfiring. I dont know the codes, I wrote them down somewhere so I need to find them. But the description was.

Vacuum Leak
Injector Sensor
EGR Sensor

I am wondering, and kinda leaning toward, if one would affect the other and give a fault that is really not there. Like the EGR sensor being messed up and making the other codes come through also. I don't have access to the truck right now, I just wanted some opinions. Thanks

 

[TheSiege]

Ok here are the codes and what not. The last one is probably just left over from when it over heated from lack of coolant
P1151 P1151 Lack Of HO2S21 Switch - Sensor Indicates Lean
P0301 P0301 Code - Cylinder #1 Misfire
P0401 Code Scanned – Expedition 4.6 EGR Low Flow
P1299 P1299 Cylinder Head Over Temperature Protection Active

 

[phucheneh]

O2 code could be related to misfire. At the least, it isn't causing your other problems, so leave it for last.

Misfire on #1 is probably from water in the plug well that was designed by a retarded invalid dipshit. Could also be a bad coil, but they get replaced far too often for what is usually simply related to moisture and the mentioned shitty coil boot/plug well design.

I've also repaired signal wires to the coil packs frequently. And by 'repair,' I mean 'ran a new wire between the coil and ECM, because fuck me if I'm cutting open the whole engine harness looking for the bad spot in the wire, you Ford douchebags.'

P0401 is probably a bad DPFE sensor. Or a leak in the hoses going to it.

Is the engine overheating?

 

[TheSiege]

Well, the guy I got it from, was using water instead of anti freeze and I am pretty sure it froze and put a crack in the radiator or the line, I just havent checked yet. So yes.

 

[phucheneh]

Erm, yeah, antifreeze is kinda critical. So you probably did have overheating. At least in the heads, which are generally going to be the hottest part of an engine; hence the temp sensor there (which is seperate from the ECT).

It could also simply be that because you lacked antifreeze and (if leaking) the system was unable to build pressure, your coolant possessed an unusually low boiling point (...212*F at sea level), which resulted in air pockets and wonky readings from the CHT sensor.

It sounds like you should probably start by fixing the cooling system and doing a compression test. IMO. If all seems okay, move on to diagnosing your misfire. 99% chance it's ignition-related, which means either the coil isn't firing (usually a wiring fault) or the coil is firing, but the spark is finding a path to ground that it likes better than 'across the plug gap.' This can be because of:

-cracked coil. You will generally see a hairline crack in the black casing that surrounds the epoxy.

-poorly insulated path between the coil and the plug. New coil boots and copious amounts of dielectric grease work well for fixing this. Sometimes other fixes are required, e.g. fixing a hose that's leaking coolant around the spark plugs- common problem with some of the rear cylinders).

-bad spark plug (cracked porcelain, usually).

You can also simply have an 'open' somewhere in the high voltage circuit. As in, rather than jumping to ground, the voltage is simply at a dead end. Unless the plugs are trashed, this is usually a result of a bad connection between the coil and plug- there is a long spring that links them. Sometimes it simply needs to be stretched a bit to keep it slightly under tension and in good contact with the coil and plug.

 

[Squisher]

As the owner of a '98 F150, I'll bet you a dollar to a doughnut that the egr passage is full of carbon. It's a 1-2 hr. fix if you've never done it before.

IIRC

Remove throttle body

Remove EGR valve

Remove large right angle elbow (throttle body adapter) that the throttle body is mounted to that takes air down into the intake. The EGR valve was mounted to the throttle body adapter on the right side. A larger passage goes into the adapter from the EGR and then a smaller passage hangs a left into the air passage while another slightly smaller passage continues on straight to the far side and hangs a left again. All these passages on mine were full up with carbon.

Here is one that I guess is off a mustang:

 

[phucheneh]

As the owner of a '98 F150, I'll bet you a dollar to a doughnut that the egr passage is full of carbon.

This is likely. I haven't done much EGR on these engines, but on most others, 'no flow' diagnosis generally consists of 1) test EGR valve (vacuum or electric) 2) If valve works and the wiring (of vac line) looks intact, you can probably go ahead and assume the passage is plugged.

Ford throws in an extra wrinkle, though, by having their remotely mounted DPFE. This is what senses pressure of both sides of an orifice in the EGR tube and provides feedback to the PCM. The 'no flow' code can be caused not just by a clog, but also a bad (whether electrically or just full of the same crap as other passages) DPFE. And they do go bad a lot.

If you can't test the sensor, though, checking the intake passage for a clog is a cheap place to start. Costs as much as throttle gasket, I guess. If that...the steel shim type can generally reused if you're careful.

 

[slag]

When I had my 97 F150, I replaced 4 of the CoP's No moisture issues, the coils just went bad over time. Horrible design, as noted above, and I had to take the fuel rail off to get to them. Great engine otherwise, as long as it doesn't spit plugs it is fairly reliable. Never had any carbon issues either, at least any that caused issues

 

[TheSiege]

Is there a way to electrically test those sensors? I should probably get a haynes manual.

 

[phucheneh]

Haynes manuals are for 'here's how to take it apart.' And they're usually bad at it.

Test what sensors?

You can check voltage supply to and signal from the DPFE, but it's unlikely to tell you much. You'll get some kind of reading. I don't believe an open or short would cause the no-flow code to set on its own. There are probably a LOT of pages out there for troubleshooting this system on Ford trucks, though, with more complete info.

Can't check O2's worth a damn without a scope.

Misfires are picked up by the crankshaft sensor. It's working. You just need to find the source of the misfire on that cylinder. Be thankful that it's localized to just one.

Given your own description of the cooling system in the truck, I don't think the CHT sensor is bad, either.

Don't go all Autozone-employee and presume that a DTC equals a failure of the indicated part. Or a failure of any part. You have to research/ponder as necessary to first find out what conditions will cause a code to be set.

Your misfire, for example. When successful combustion occurs, the crank throw associated with the firing cylinder is getting slung back towards the ground by the power generated. For every two rotations of the crankshaft, there are going to be eight surges in crankshaft acceleration, each from a cylinder firing. In your case, the sensor is generally picking up 7, and the PCM is noticing that every time #1 comes up in the firing order, jack shit is happening.

So to be very vague, here is a complete list of what could be wrong with that cylinder to cause your code:

-lack of compression (mechanical failure. blown headgasket, burnt valve, stuck valve, cracked head, cracked cylinder, melted rings/ring lands, hole in piston. maybe you sucked a bolt into it and you've got some kind of hat trick of mechanical failure. who knows.)

-lack of fuel (injector coil is bad, injector is clogged, injector wiring is bad, injector driver is toasted.)

-lack of spark (bad primary coil winding, bad secondary coil winding, cracked coil, wiring problem on coil primary side (12v supply and ground), wiring problem on coil secondary side (issue between coil and plug), bad spark plug, toasted coil driver.)

If you're starting to think, 'wow, that code doesn't tell me dick!'...CORRECT, SIR.

Step 1: Swap coils between #1 cyl and another nearby. If the misfire moves with it, you have a coil issue. If it does not, you have a different issue. If it works on the other cyl, look for a wiring problem with the other. You should have 12v constant on one wire and pulsed ground on the other. I like to measure these with the coil plugged in. Without the load of the primary winding, you can get normal looking readings with bad wiring. Watch out for mild electrocution. It's fun.

If everything checks out (should be able to hold the coil, plugged in, with the boot facing the engine and see a nice solid arc), then inspect your plugs, maybe try swapping that as well.

It's unlikely you will get past there, but if you do, I would compression test.