It first started with a huge lose in power (can't rev over 3,500 rpm or get over ~55 mph) and a pig on gas!
P0125 showed up so after looking for a while I figured I would change the sending unit - single wire (3F1Z-12A648-A), coolant temp sensor (ECT I believe) to PCM -two wires (F7DZ-10884-AA) and then the thermostat. - Throughout this time the heater worked perfectly fine. The temperature gauge would get up to C but never very far from it. I would never get to the middle.

In doing so I drained the coolant took off the intake hose (cleaned the butterfly valve in the process) then got clean access to the sensors and the two 10mm screws for the thermostat. I got it all off and apart just fine minus the one stubborn plug on the sending unit (single wire). Putting the sensors back in took more effort then taking them out it could have been the anti-seize or thread sealant that came on it. Anyways, I also noticed that BOTH the new sensors I picked up from the dealership looked identical. Both of them looked similar to this:



Granted the tops were different colors but the ends (metal) were the same or at least I couldn't tell the difference. The ones I took out of the block were definitely different. The sender (single wire) looked like the one above but the sensor looked like this with the pointed tip (I can upload pictures too):


I put the coolant temp sensor in first (two wires) and the plug went on fine.

Put the sender (single wire) in and I couldn't get the cap on... it was too tight. I looked at the old one and it seemed like one of the ribs to guide the plug on was off by the thickness of the rib... I tried again and thought maybe it was me and eventually cracked the cap.

Now the coolant gauge doesn't work at all doesn't even move. I then got it scanned and saw P0117 come up... Is this for the sender (1 wire) or the sensor (2 wires)

Also I read that once P0017 comes up it could be difficult to start the truck... I thought it was because there was gunk left over from me cleaning the butterfly valve but that may be it instead.

My questions are...
Did I mix the sensors up? I really don't think so I double checked before I put them in that only one was open at a time.

Was I given the wrong sensor for the coolant temp as it looked different at the tip? I have no clue? Looking at threads for P0117 it seems to be the sensor. I will be going back to Ford tomorrow am to take the old ones in to check.

Why wouldn't the plug fit on the sender (single wire)?... I have no clue.

If anyone has suggestions or could help that would be great!

 

Go to the Motorcraft website & look up their part numbers for the two temp sensors for your Ranger year engine & see if they match what you got from the Dealer & what came out of the vehicle.

 

I'd say you probably were given the wrong part. The sensors look very similar which often leads to confusion. I recall a few years ago that rockauto sent me the wrong part (I ordered an ECT and they sent me the temp. sending unit). The way I found out is the same thing you are running into - there s a slight difference in the harness connectors. I couldn't get the darn thing to connect properly.

IIRC, the ECT is the one with the "rib" centered, while the sending unit is the one with the "rib" that is slightly off center.

Make sense?

 

By the way, F7DZ-10884-AA is the part # for the temp. sender (single wire).

And I'm pretty sure the other part # you noted (3F1Z-12A648-A) is the ECT.

You may have the correct parts after all, and simply mixed them up.

 

I went to their website but their part numbers seem to be different all together then what they use at the dealer... Any insight? - I found one of them...

This is what I found:

ECT:
2003 Ford Ranger Engine Coolant Temperature Sensor | FordParts.com

EDIT: - I think this is actually it: http://www.fordparts.com/Commerce/Pa...d&model=Ranger

Looking at the description this says it is rectangular as the first one says it is rounded which it isn't.

Coolant Sender:
2003 Ford Ranger Engine Coolant Temperature Sender | FordParts.com - F77F 10884-AA Yes they gave me the wrong part.

Yeah, I can see what you are saying... the rib opposite to the connecter tab was not lined up with the one on the plug. I couldn't tell you to what side. This is what would cause the P0117? I thought it was something with the ECT sensor? Anyhow, the coolant gauge is dead which is I didn't think was connected to P0117.

 

What is the difference between these two ECT Sensor besides the # and price:

(I think I need this one)
1: 2003 Ford Ranger Engine Coolant Temperature Sensor | FordParts.com

vs
2)
2003 Ford Ranger Engine Coolant Temperature Sensor | FordParts.com

Am I missing something?

 

PO117 is an ECT-related code. It was a good idea to replace it. But it appears you may have replaced it with the wrong part (temp. sender).

Ditto with the dead temperature gauge - it appears you may have replaced the sending unit with the wrong part (ECT) .

 

So did I mix the two sensors up or did I just get the wrong ones... I made a concious effort to try to make sure I put the ones in the right spot.

On the receipt I thought the F7DZ-10884-AA was the sensor - ECT and the 3F1Z-12A648-A was the sender

Looking at the two parts below and the diagram they seem contradicting unless I am just not seeing it right...

This is the two wire connector (I believe):
Official Ford Parts Site | Buy Motorcraft & OEM Ford Parts Online | FordParts.com
10884 on the diagram - that is relatively easy and straight fwd

This I thought was the single wire connector:
Official Ford Parts Site | Buy Motorcraft & OEM Ford Parts Online | FordParts.com
But looking at the diagram 12A648 it seems to contradict the one above no? It looks to be in the same spot or am I missing something?


Okay, so I checked the ones I took out and this is what they had on them:
F77F-10884-AB was the sender (single wire) - Cylinder type bottom
F5AF-12A648-AB was the sensor (2 wires) - Tapered bottom

So I did install them backwards then...I think... these part numbers are confusing me - Now if you look back at the motorcraft parts I listed above look at the 10884 which looks like it should be the two wire sensor but then the second link looks like the 12a648 should be the two wire. Anyways, what I'll probably do is go ahead and switch them and see what happens.

 

Okay, I was able to switch the sensors (a bit of a longer story there) but the coolant temp gauge now works and after I cleared the code and started up the truck it idled around 650-700 rpm which is has never done before it has always been well above 1,000 rpm or closer to 1,500 rpm.

Anyways it still seemed like it didn't have much power after I drove it for 10 min. Does the computer need more time to reset? Or do I have another issue?

I gave it full throttle (just before I hit the stepdown switch). It down shifted one and would not rev above 3,000 rpm. I have looked around for other similar stories and people say that their catalytic converters essentially collaps on it's self... I guess there isn't really a way to tell unless I take the exhaust off? I put my hand over the end and it seemed like it had good pressure.

Something else I saw was there is this cylinder looking items on the top right of the throttle body, what is that? It was pointed out to me that, that could be causing the issue?

Any place else to check? Thanks again for all of your help

 

When is the last time the truck had a tune-up? Spark plugs are how old? Fuel and air filters, when were they last changed?

 

Ok so you now believe that the temp sensors are properly installed & hooked up, so lets go back & revisit your first post. The gas mileage dropping & a P0125 trouble code you posted is for Insufficient Coolant Temp For Closed Loop Fuel Control. SO, have you confirmed with a thermometer, IR temp sensor, Scantool, or the like, that the engine is actually getting up to full operating temp of around 195F????

The drop in mpg & thouble code suggests that you may have a stuck open thermostat. That would have the computer operate the fuel trim on open loop, which is a richer air/fuel mixture, which over time could foul the spark plugs, which could misfire when going wot, or at throttle up & that open loop mode of operation will lower mpg!!!! Won't do the cat converter any good either as it can cause the converter to over heat & melt the ceramic matrix down!!!! Use your vacuum gauge to perform a clogged cat converter test to see if its been damaged from over heating trying to process the rich fuel mixture & is causing excessive exhaust back pressure.

 

Plugs and fuel filter were thought to be the first issue. This was done about a month and a half ago.


Yes, the scantool verified the engine is getting to the proper operating temp 195°+

I don't know if the thermostat was stuck open because the truck would get heat just fine and heat up like normal. I thought if it either took a while to get hot or didn't blow hot then the thermostat was stuck open.

Yeah, agreed, over time that would destroy the cats. So check the vacuum pressure by connecting the vacuum gauge to a port after the throttle body and see how it runs at idle then 2K rpm?

Thank you for your inputs.

 

If you were getting good heat, then the thermostat was likely ok & maybe the engine computer temp senser was giving a corrupt PID.
Here in scenario 14, is how to use & interpret a vacuum gauge reading for a clogged exhaust. How to Use and Interpret a Vacuum Gauge

If it was run long enough with a rich air/fuel mixture, it could foul the spark plugs, so like Rockledge has suggested, at least check the plugs, air filter, air box & air tube for restrictions, perform a fuel pressure & delivery volume over time test & if low, change the fuel filter as he suggested. Restrictions in air or fuel delivery will limit power output.

 

Yeah, the thermostat could have been perfectly fine but I was right there and for $20 or whatever it was might as well if it had never been done. Plus most of the coolant was water anyways.

Yeah, I figured prolonged periods of rich could foul the plugs and destroy the cats...

Thanks again for all the help everyone!

 

I was able to find the problem. It was a combination of the sensors and the catalytic converters... After the sensors it still didn't have much power but the CEL was off. I got the cats fixed and she is back to normal. Thanks for your help!