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Temperature sender/sensor

Tiny
CDPSRAR
  • MEMBER
  • 16 POSTS
Update: Just now drove it enough to warm up. Shows Fuel System 1 CL-Fault. All Fuel Trims stay negative. And now I'm thinking the O2 sensor that shows 0.0 volts all the time may be an issue. It's upstream at 02S11. Please let me know what you think. Thanks again.
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Tuesday, August 11th, 2020 AT 4:48 PM
Tiny
CARADIODOC
  • MECHANIC
  • 33,741 POSTS
It's very rare for a rough running engine to be caused by an oxygen sensor. The computer doesn't adjust mixture that much based on its readings under normal operating conditions. The numbers say it's taking away fuel in an attempt to correct the mixture. You might look at fuel pressure. If it's too high, look for a restricted return hose to the gas tank. If there's a fuel pressure regulator on the fuel rail on the engine, that should have a vacuum hose hooked to it. A missing or cracked hose will trick the regulator into thinking the vacuum is low, due to acceleration, and the need for higher fuel pressure to make up for the reduced vacuum pulling in fuel molecules from the injectors.

You might want to remove the EGR valve and reinstall it with a thin metal shim to block the ports. If that solves the rough running, that is the system to look at.
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Tuesday, August 11th, 2020 AT 4:48 PM
Tiny
CDPSRAR
  • MEMBER
  • 16 POSTS
Update: There is a vacuum line running from the throttle body to a switch that apparently talks to a vacuum reservoir. That line was collapsed allowing no air flow. Replaced it and wow! Huge difference when driving and no codes. Still have a rough idle after it warms up but at the moment I'm just happy it's running so much better. Thanks for your hint regarding the results of a vacuum leak. Thanks very very much for all your help.
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Tuesday, August 11th, 2020 AT 4:48 PM
Tiny
CDPSRAR
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  • 16 POSTS
Hello again gentlemen. It's been quite a while since I wrote due to the fact that I've been steadily working on the vehicle in an at attempt to get it to pass inspection. I've replaced the following:
Thermostat
Vacuum control valve
IAC valve
All O2 sensors
Temperature sensor and sender
Coil pack
Plugs and plug wires
All vacuum lines (and I mean ALL of them)
Mass air flow sensor
Verified no vacuum leaks
Verified EGR valve is functioning properly and replaced vacuum lines to the EGR solenoid and control valve.

I no longer get a myriad of trouble codes. Just one and it is constant: P0175:
Running rich in bank 2. No other codes show up anymore.

I can clear the code but it comes back almost immediately and will not allow the vehicle to pass inspection. It still runs smooth when cold but but gets rough as the motor warms up. It no longer dies at a stop light but still idles poorly and produces a rich gas smell. Although not near as bad as it used to be.
A mechanic friend said it's my TPS, but why would that be specific to Bank 2? I'm thinking a bad fuel injector in bank 2. Possibly stuck and dumping fuel all the time. If that's possible.

If you hear a scream off in the distance it's just me venting my frustration. Any suggestion would be most welcome and much appreciated.

Thank you,
Richard Reed
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Tuesday, August 11th, 2020 AT 4:48 PM
Tiny
CDPSRAR
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  • 16 POSTS
Oops. Forgot to mention one thing: My short and long term fuel trims are way out of spec all the time for bank 2 after the motor warms up: Anywhere from -16% to -25%. Bank 1 is always well within spec.

Thanks,
RR
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Tuesday, August 11th, 2020 AT 4:48 PM
Tiny
CARADIODOC
  • MECHANIC
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Forget the throttle position sensor. He has about the least effect on fuel metering calculations.

Put a fuel pressure gauge on it and watch what happens over time when the engine is off. Fuel pressure should hold for weeks, or at least a few days. If an injector is leaking, pressure will slowly bleed down over minutes. It is still unlikely that would cause the horrendous rich condition.

You might consider switching the injectors from side to side, then see if the high fuel trim number switch to the other side.

Does your engine use an EGR valve with tubes running to each cylinder? Ford had a lot of trouble with those on pickup trucks. Those tubes become plugged with carbon, then the affected cylinder runs especially fine since it's only getting fresh air. The system controls the amount of exhaust gas flow to the cylinders, and that volume is supposed to divide up evenly between all of them. As more and more tubes become plugged, all of the flow goes to the one or two cylinders that still have clear tubes. With a cylinder getting six or eight times the EGR flow it is supposed to have, there is no fresh air or oxygen to mix with the fuel. The fuel from that cylinder goes into the exhaust, unburned, and you get a misfire from the last remaining good cylinder.
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Tuesday, August 11th, 2020 AT 4:48 PM
Tiny
CDPSRAR
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  • 16 POSTS
Caradiodoc,
Thank you for replying. My EGR system does not have tubes running to each cylinder. It's a 1999 Explorer 4.0 OHV. As you suggested, I did a fuel pressure test. I attached the gauge to the valve on the fuel rail. When running it read 68 to 70 PSI. Fluctuated very fast between the two numbers. I turned the motor off and the pressure held at 68 for about 2 minutes then slowly began to drop. Went down 10 PSI in 15 minutes. That indicates a leak somewhere, right? I have not yet switched injectors from side to side because It's my only vehicle and I won't have that kind of down time until the weekend. Gotta pull the intake to get to the injectors. If you think of anything else please let me know. I will post my results from switching injectors Sunday or Monday. Thank you for your time.

R Reed
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Tuesday, August 11th, 2020 AT 4:48 PM
Tiny
CARADIODOC
  • MECHANIC
  • 33,741 POSTS
There's three places fuel pressure can bleed down from. By far the most common is a leaking fuel injector. Least common is a leaking check valve in the fuel pump. For those engines that have the fuel pressure regulator on the fuel rail on the engine, that can leak too. You can identify that by using a hose pinch-off pliers to pinch the return hose.
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Tuesday, August 11th, 2020 AT 4:48 PM
Tiny
JDUKEFAN21
  • MEMBER
  • 1 POST
  • 1998 FORD EXPLORER
  • V8
  • 4WD
  • AUTOMATIC
  • 165,000 MILES
The car will not heat up inside the car.I was told the heat sensors needed replacing? I thought it was a thermostat any help
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Tuesday, August 11th, 2020 AT 4:50 PM (Merged)
Tiny
BLACKOP555
  • MECHANIC
  • 10,371 POSTS
First turn the car on and let it get to operating temperature with the heater on full and the hottest setting, then go feel the heater core hoses, if they are both hot then you may want to check your blender door in the dash.

If one is hot and the other isnt you may want to flush the heater core.

And if neither are hot change the thermostat and check the heater control valve.
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Tuesday, August 11th, 2020 AT 4:50 PM (Merged)
Tiny
BOBD79
  • MEMBER
  • 2 POSTS
  • 1997 FORD EXPLORER
  • V8
  • AWD
  • AUTOMATIC
  • 160,000 MILES
Need to know where this sensor is and how to replace it
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Tuesday, August 11th, 2020 AT 4:50 PM (Merged)
Tiny
RASMATAZ
  • MECHANIC
  • 75,992 POSTS
All you need is an open end wrench

Heres a guide to look at, not vehicle specific but pretty much the same thing

https://www.2carpros.com/articles/coolant-temperature-sensor-cts-replacement

See attachments below for your vehicle
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Tuesday, August 11th, 2020 AT 4:50 PM (Merged)
Tiny
FENWAYJEFF
  • MEMBER
  • 3 POSTS
  • 1996 FORD EXPLORER
  • V8
  • 2WD
  • AUTOMATIC
  • 191,000 MILES
I have just replaced the radiator, thermostat, hoses and temp sending unit. I can sit it at idle for 45 min and it just runs a little hot but as soon as I drive it, the temp gage red lines and the check engine light comes on. I cant seem to figure out why it is overheating, please help me.
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Tuesday, August 11th, 2020 AT 4:50 PM (Merged)
Tiny
JACOBANDNICKOLAS
  • MECHANIC
  • 108,179 POSTS
It sounds like you replaced everything. Did you check to make sure there is no air in the cooling system? Also, you you may need to check for a bad head gasket.
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Tuesday, August 11th, 2020 AT 4:50 PM (Merged)
Tiny
FENWAYJEFF
  • MEMBER
  • 3 POSTS
  • 1996 FORD EXPLORER
  • V8
  • 2WD
  • AUTOMATIC
  • 191,000 MILES
I have just replaced the radiator, thermostat, hoses, temp sending unit, and gotten all bubbles out of the system. I can let it sit at idle for 45 min and the temp is high but not overheating. If I drive the vehicle it will get all the way to redline on the temp gage and the check engine light comes on. Please help me
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Tuesday, August 11th, 2020 AT 4:50 PM (Merged)
Tiny
POORMNSDVD
  • MEMBER
  • 9 POSTS
Do you have to keep adding coolant?
Excisive water in exhuast?

And is it actually over heating?
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Tuesday, August 11th, 2020 AT 4:50 PM (Merged)
Tiny
FENWAYJEFF
  • MEMBER
  • 3 POSTS
Coolant level stays the same, no excessive water in exhaust and the water/coolant mix after it says its hot is boiling
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Tuesday, August 11th, 2020 AT 4:50 PM (Merged)
Tiny
BLUELIGHTNIN6
  • MECHANIC
  • 16,542 POSTS
Hello and thanks for donating!

You will need to have the water pump tested, it may not be pushing coolant through system correctly to cool engine.
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Tuesday, August 11th, 2020 AT 4:50 PM (Merged)
Tiny
POORMNSDVD
  • MEMBER
  • 9 POSTS
What code is the ecm generating

is there any coolant dripping from the pin hole at the water pump
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Tuesday, August 11th, 2020 AT 4:50 PM (Merged)
Tiny
CARLA REED
  • MEMBER
  • 27 POSTS
  • 1999 FORD EXPLORER
  • 5.0L
  • V8
  • 2WD
  • 246,600 MILES
Need to know where to locate this on my truck. See image below.
Thanks,
Carla Reed
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Wednesday, October 14th, 2020 AT 12:56 PM (Merged)

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