1997 Ford Explorer - V8 - 5.0 - AWD

Hello Explorer Fans.

I have been on the forums for some time and have extensively read many threads. I have enjoyed the forums so far. Now I have a question of opinion for you all.

I currently own 97' V6 SOHC Sport and I love it. I was going to SAS it, but Id rather do it to a V8 Explorer, plus, manual TC's are readily available for the swap.

To get to the point, I'm looking at a 97' 5.0 AWD Explorer (166,000 miles) (for a few hundred bucks). It's a solid vehicle, straight but its flashing a few codes. I looked up the codes here on the forums and it appears to be a "simple" fix. It idles well, but has an obvious 'lumpiness' to it. When you accelerate under load, you can sort of hear and feel it. The codes I got were P1132 - Lack of Oxygen Sensor indicates Rich and P1131 - Lack of Heater Oxygen Sensor indicates Lean. Both appear to be O2 sensor issues which may not be that big a deal. The trans seems to shift well with no obvious issues.

I'm very mechanical in nature (I work on my own cars/trucks) and fabrication of all I want to do...is what I do.

I just wanted a few opinions on the success of fixing this issue and any potential things I should look for before i pull the trigger and pick this thing up.

Thanks everyone.

 

[Mbrooks420]

These trucks seem a little finnicky about plugs and wires, maybe a set of plugs will clean up the running some

 

[CDW6212R]

Ditto, replace the plugs and wires if they may be old, so anytime on a new purchase.

 

[Turdle]

Good score.
For the vent function issue-where you were on track. Maybe this will help

How to: - 2nd Gen NO AC ( or heat) FROM VENTS!!! A "How to" what to look for thread

 

[97-5.0]

Replace fuel filter under drivers side frame rail, if it still runs bad check fuel pressure from valve on fuel rail, passenger side front of engine

If it is below 30 psi at any time, idle and high Rev, then get a new pump, it will "run", on 20psi but it won't be happy at all!

Rockauto for Ford plugs and wires!

 

[Spudhut]

Good score.
For the vent function issue-where you were on track. Maybe this will help

How to: - 2nd Gen NO AC ( or heat) FROM VENTS!!! A "How to" what to look for thread

Thank you @Turdle . Excellent write up by the way and some of the other comments turned on the light bulb linking my issue to the fan motor resistor (I should have known this). I did check all my vacuum actuators and they are all holding 'in position' as they should.

I picked up another fan switch from local 'Pick-n-pull' yard...no go on the fix

 

[Spudhut]

I decided to pull the spark plugs to inspect them. (Cyl 7&8) I stopped here - I'm sure the rest are the same.

They are Motorcraft Platinum.

Seriously, I don't think they were ever changed. They have a gap that's almost 1/8" wide. (they were normal black on the ends, I used a wire wheel to clean them off) New plugs are on the way!

 

[CDW6212R]

Great, know you've moved closer to knowing it's solid again. I'm glad they came out easily, sometimes being so old they don't.

 

[Spudhut]

Did more work on the Ex last night.

So I found an Ohm test for the IAC. You can do an ohm check on the unit to verify its "good". However, I did pull it off and clean the inside out; there was only a little carbon build up. Grab a multimeter and put on Ohms setting. You want to be in the range of 7 - 14 ohms. Mine came in at 9.4 ohms. Just for kicks, i went to my local 'Pick-n-Pull' and tested a few on their cars and they all came in the same range.

I picked up some new plugs so I can swap out the old ones. What a bear to get to them - especially through the fender well. Thankfully they came out easily. These are placed in their respective cylinders (top of picture is front of engine). A few had gaps as large as .70. The tips on the electrodes were quite burned.

Glad I did the plugs. Its nice to run into other 'hidden' issues when doing other tasks. I found #4 wire barely connected at the boot; electrode hanging out of the insulation. Thankfully I have new wires on the way! Could be the main reason for the slight 'lumpiness' in how the engine runs.

I have been researching on why the blower motor only works on High speed setting, and why the fan is possibly turning in the opposite direction. There is little to no air moving throughout the system. I picked up another fan switch hoping that would be the fix, but I was wrong. Through my research, I was reminded about the blower motor control module. It's located under the fan housing in the engine bay (passenger side rear corner) so I pulled it out using an 8mm socket to inspect it. Not good. Even the connector was tough to pull off due to corrosion. These don't have a gasket on them and a lot of this rust comes from condensation collected in the heater box over time. If your fan isn't working properly, its a good sign that the diode in this resistor is blown. Now, don't be mistaken, I picked up a unit from a random Gen2 Explorer thinking it would work. There are 2 different types available. You have a 'Manual' type and an 'Automatic Temp Control' type unit.

This one pictured below is the 'manual' type.

Automatic Temperature Control

 

[1998Exp]

In the photo of the manual (resistor-type) unit, the pointed component is not a diode. It's a thermal fuse, designed to disconnect the current if there is no airflow (due to stuck rotor in the blower, usually).

 

[Spudhut]

Thanks @1998Exp for the clarification, that makes sense

 

[Spudhut]

I picked up another Blower Fan Resistor and installed it. To confirm, that was my speed issue. I figured I would clean the fan blades as well, so I pulled the fan out since I had the room and I found a heater box full of acorns...LOL. This is after I cleaned it.

Even though I replaced the resistor (grey connector in lower right of photo), the fan speed is a bit off. Its another used part in good non-rusted condition. The fan changed speeds but compared to my Sport heater fan, its seem slower and the air flow is a lot less. I'm going to swap fans with Sport to see if there is any change/difference.

 

[Spudhut]

My cruise control switches were basically trashed - (bad material design i suppose) found some good ones at JY and replaced.

Old Units:

"New" switches

 

[Spudhut]

For anyone following: I did a quick tune up on the engine. I installed new spark plugs, new plug wires, air cleaner and checked the connections on the motor. Fired it up and the motor purrs nicely. It did have a little trouble initially starting, but ill investigate that further. I plan on doing a PCV and Hose change just to make sure its breathing good.

I took it for a test drive and it felt strong. The trans however seemed to shift good. It certainly has different shift points than a 4.0/Sport model.

 

[CDW6212R]

Very good. Now run some fuel injector cleaner through it a couple of times, and clean the IAC if it hasn't been done before, and enjoy it.

 

[97-5.0]

Trust me, do a transmission fluid change,
Unhook the cooler line and start car- stop when bubbles come out of line, then
drain the torque converter - round black 3 inch rubber plug at bottom of transmission, inside there is the TC -turn engine by hand untill the drain plug shows up - factory TC has drain
Pull pan and change filter - optional - do it
Fill 6L then start for 2-3 seconds then Off
Fill 6L then run for 2-3 then off
Your filling the TC with fluid
Top it up, start and shift thru every gear "foot on break", getting air out of system
Check level at idle, level ground, add if needed,
Don't forget the cooler line!

Sorry don't know how many L.
Do it again when you feel the transmission get weaker, over a year depending how hard you drive, a new filter Will last Year's+

 

[CDW6212R]

I would expect that owning a new vehicle suggests changing all fluids and filters. I did it all with my new 98 last year. The 302 trans takes 12+ quarts of ATF. I added a deep pan and ended up using about 15 quarts, but that's from empty(I had the VB off also for a couple hours). There's a couple of quarts trapped above the VB in all automatics, so loosening that drains a lot more.

 

[Spudhut]

Thanks Guys!

 

[Spudhut]

Been a good day. Took 1/2 day off from work and pulled this 4406 TC this morning with the stick, boot, shifter, cover plate...everything. 20 degree's out here...gotta love the dedication to the hobby!

Ill need to go back again for the driveshafts.

There were 4 more trucks out there with 4406's and shifters out there. (98' and up)

 

[Spudhut]

Get it!!, give full tune up, look for cast exhaust manifolds, add ground to coil pack mount, do full trans fluid refresh and add larger external cooler and your good to go for a while!!

What are the cast manifolds on typically?

 

[WhiteLX]

What are the cast manifolds on typically?

99-01