Where's the coolant temp sensor on a duratec? - Ford Focus Forum, Ford Focus ST Forum, Ford Focus RS Forum
Ford Focus Forum
HomeContact UsAbout UsGalleryDiscussion ForumsMarketplace


Go Back   Ford Focus Forum, Ford Focus ST Forum, Ford Focus RS Forum > Ford Focus Tech Discussions > General Technical Chat

General Technical Chat This section is for technical discussions relating to general maintenance, electrical issues, engine trouble, and recalls.

Search This Forum | Image Search | Advanced Search    
Ford Focus Tire & Wheels FocusFanatics Merchandise

Reply
 
Thread Tools Display Modes
Old 06-18-2012, 10:51 PM   #1
gjm4l
Focus Enthusiast
 
gjm4l's Avatar
 
Join Date: Dec 2011
Fan#: 93287
Location: Charlotte, NC
What I Drive: 2007 Dark Toreador Red ZX3 S

Posts: 83
FF Reputation: 1 gjm4l Good Standing Member
Buy-Sell-Trade Rating: (0)
Where's the coolant temp sensor on a duratec?

Figures I finally get around to cleaning up the focus, spent all day on it and the next day the check engine lamp comes on heading to work..... Pulled a PO128 code which is a low coolant temp reading. Everything is checking out fine so I imagine it's the sensor. But compared to my last vehicle (a 92' ranger) the duratec is COVERED in sensors and I thought it had to dang many. So can anybody tell me where the coolant temp sensor is? Or excuse me the Engine Coolant Temperature Sensor (ECT) It's nowhere I expected it to be so I'm confused? Appreciate any help! Including if you know something about this code that I don't know


gjm4l is offline  
    Reply With Quote Quick reply to this message
Sponsored Links
Advertisement
 
Old 06-19-2012, 12:05 AM   #2
Grumpy
Focus Addict
 
Join Date: Feb 2007
Fan#: 43791
Location: Vancouver, B.C.
What I Drive: 2005 Sonic Blue ZX3

Posts: 868
FF Reputation: 28 Grumpy Great Standing Member
Buy-Sell-Trade Rating: (0)
The Duratec uses a Cyl. Head Temp. sensor if I remember correctly. It's located between spark plugs 2 and 3. BUT.......if your coolant level is in the ball park then I'll bet your thermostat is kaput. It is not fully closing and the coolant temp is not getting "up to temp" (not sure of the exact temp., but is usually around 170 to 180 deg. F) quickly enough, and the ECM is setting the P0128.
Grumpy is offline  
    Reply With Quote Quick reply to this message
Old 06-19-2012, 06:49 AM   #3
whynotthinkwhynot
Captain TMI
 
whynotthinkwhynot's Avatar
 
Join Date: Jan 2005
Fan#: 18416
Location: the armpit of TN, Memphis, TN
What I Drive: 05 Focus Wagon; 13 C-Max SEL

Posts: 20,275
Points 27,590, Level 98
Points: 27,590, Level: 98 Points: 27,590, Level: 98 Points: 27,590, Level: 98
Level Up 24% Completed
Level up: 24% Level up: 24% Level up: 24%
Forum Activity 12%
Activity: 12% Activity: 12% Activity: 12%
FF Reputation: 270 whynotthinkwhynot Outstanding Standing Member whynotthinkwhynot Outstanding Standing Member whynotthinkwhynot Outstanding Standing Member
Buy-Sell-Trade Rating: (1)
92 Ranger = not Duratec. Those engines didn't appear until 03. Back in 92 you had OBD1 engine controls which used one sensor for gauges, and another sensor for computer input. That caused a few more sensors than are used now on OBD2 systems where you have one sensor that is for the computer, and the computer sends a signal to the gauges.

I would see if someone has a infrared thermometer where you can check the temperature of the radiator, engine block, and upper radiator hose before you dive into a thermostat job on this car. There is also a way to double check the sensor's readings with the electronic odometer. Key off, press and hold the trip odo reset button, turn key on, continue to hold reset button until the odometer reads [test], now each time you press and release the odo reset button you scroll through one of 30 test functions. It will remain in test mode until you turn the key off. You need to look for the one that reads [40 C] or whatever your temperature should be in C at the time. If the car has cooled overnight, then it's likely to be close to ambient temp. If it has not cooled, expect a higher reading. Drive the car in test mode. You should see your engine temp rise to about 95C, then drop down to 80 or so as the thermostat opens. This cycle will continue several times before the engine temp settles above the thermostat temperature of 92C. You should compare your findings with the test mode with those of the infrared thermometer under the hood. I would expect a 10% difference even if things are working right. More than that could be indicative of a problem with the sensor.

You should also check the sensor wiring, and if you are in test mode and you see sudden jumps or drops in temp to 0 or some ridiculously high temp like 200C, then you know there is a problem with the sensor itself.

The thermostat in this car is not a simple task to replace, so that's why I recommend methods of diagnostics first to be sure that the thermostat is what is failed. With a failed thermostat you won't see the cycling of temperature as I wrote about above. The temp will simply slowly climb up.

If you decide that you want to just replace the thermostat, you'll need an intake manifold gasket, and the correct thermostat. You need an inspection mirror to verify whether or not you have a thermostat with a supplemental sensor built into it. The thermostat is located under the intake manifold on the right side of the engine near cyl 1. Follow the lower radiator hose up to the block, and that plastic doomaflatchie is the thermostat. It is built into the housing. Look online at a retailer with pictures like Rock Auto.com, and you'll see what you should be looking for. If you see anything electrical that plugs into the thermostat housing, then you need the more expensive thermostat. I would also suggest purchasing the lower radiator hose whether you need it or not, and a new PCV hose whether you need it or not because those are not expensive and you need to remove the intake manifold to replace those also.

You will experience sticker shock when you see the price on this thermostat- even from a low priced retailer like Rock Auto. I shudder to think what Autozone is charging for this thermostat. To give you perspective, you can purchase your own infrared thermometer for much less than you can purchase even the cheap version of this thermostat that doesn't have a sensor built into it.
__________________
Be eclectic.
---The Complete How-To Archive--

Moderating everything now, let me know if I can help.

Quote:
Originally Posted by the user formerly known as ZX3_Chick View Post
You're special aren't you.
whynotthinkwhynot is online now  
    Reply With Quote Quick reply to this message
Old 06-19-2012, 06:57 AM   #4
whynotthinkwhynot
Captain TMI
 
whynotthinkwhynot's Avatar
 
Join Date: Jan 2005
Fan#: 18416
Location: the armpit of TN, Memphis, TN
What I Drive: 05 Focus Wagon; 13 C-Max SEL

Posts: 20,275
Points 27,590, Level 98
Points: 27,590, Level: 98 Points: 27,590, Level: 98 Points: 27,590, Level: 98
Level Up 24% Completed
Level up: 24% Level up: 24% Level up: 24%
Forum Activity 12%
Activity: 12% Activity: 12% Activity: 12%
FF Reputation: 270 whynotthinkwhynot Outstanding Standing Member whynotthinkwhynot Outstanding Standing Member whynotthinkwhynot Outstanding Standing Member
Buy-Sell-Trade Rating: (1)
Nevermind, I just checked, Autozone and Rock Auto have similar prices on these parts. RA was $125 for the one with the sensor, and $20 without sensor. The Zone wants $150 and $27 respectively. Shipping would make the cheaper one more expensive to purchase from RA unless your sales tax is high. I already know that intake manifold gaskets are similarly priced- about $25. I don't know about PCV lines or the valve itself.

There, now you don't have to have sticker shock at least not later. Hopefully you don't have the sensor.
__________________
Be eclectic.
---The Complete How-To Archive--

Moderating everything now, let me know if I can help.

Quote:
Originally Posted by the user formerly known as ZX3_Chick View Post
You're special aren't you.
whynotthinkwhynot is online now  
    Reply With Quote Quick reply to this message
Old 06-20-2012, 10:04 PM   #5
gjm4l
Focus Enthusiast
 
gjm4l's Avatar
 
Join Date: Dec 2011
Fan#: 93287
Location: Charlotte, NC
What I Drive: 2007 Dark Toreador Red ZX3 S

Posts: 83
FF Reputation: 1 gjm4l Good Standing Member
Buy-Sell-Trade Rating: (0)
Thanks for the info. I had no idea there was a way to test from the display I'll be checking that out tomorrow. I checked with the infrared and it's running normal, nothing seems to be off so I'm thinking it's the sensor. But either way I have the tstat housing without the extra sensor so glad it's not holy crap expensive when that time comes. On an interesting note I reset the computer to hide/clear the light and it hasn't come back on since? Which is random whether it was the sensor or the tstat..... I will be playing with that nifty feature I had no idea existed tomorrow thanks whynothtinkwhynot!

Oh but what I meant was the Ranger had WAY fewer sensors not to mention easier to trace systems than the focus does. Maybe it's because I've never had a FWD so it's all discombobulated to me but wow is it confusing
gjm4l is offline  
    Reply With Quote Quick reply to this message
Old 10-29-2012, 07:16 PM   #6
TheSteelGator
Focus Rookie
 
Join Date: Aug 2012
Fan#: 103127
Location: Elizabeth, PA
What I Drive: 2002 Sonic Blue SVT ZX3

Posts: 8
Points 49, Level 1
Points: 49, Level: 1 Points: 49, Level: 1 Points: 49, Level: 1
Level Up 98% Completed
Level up: 98% Level up: 98% Level up: 98%
Forum Activity 0%
Activity: 0% Activity: 0% Activity: 0%
FF Reputation: 1 TheSteelGator Good Standing Member
Buy-Sell-Trade Rating: (2)
Quote:
Originally Posted by whynotthinkwhynot View Post
... You need to look for the one that reads [40 C] or whatever your temperature should be in C at the time. If the car has cooled overnight, then it's likely to be close to ambient temp. If it has not cooled, expect a higher reading. Drive the car in test mode. You should see your engine temp rise to about 95C, then drop down to 80 or so as the thermostat opens. This cycle will continue several times before the engine temp settles above the thermostat temperature of 92C. You should compare your findings with the test mode with those of the infrared thermometer under the hood. I would expect a 10% difference even if things are working right. More than that could be indicative of a problem with the sensor. ...
Thanks for the great information, whynotthinkwhynot. So... let's say I've driven around in test mode and the temperature reading hasn't gone past 67 C. But my temperature gauge needle is directly in the middle, and I have plenty of heat coming out of the vents.

Ideas?
TheSteelGator is offline  
    Reply With Quote Quick reply to this message
Reply

Bookmarks & Social Networks

Quick Reply
Message:
Options

Register Now

In order to be able to post messages on the Ford Focus Forum, Ford Focus ST Forum, Ford Focus RS Forum forums, you must first register.
Please enter your desired user name, your email address and other required details in the form below.
User Name:
Password
Please enter a password for your user account. Note that passwords are case-sensitive.
Password:
Confirm Password:
Email Address
Please enter a valid email address for yourself.
Email Address:

Log-in

Human Verification

In order to verify that you are a human and not a spam bot, please enter the answer into the following box below based on the instructions contained in the graphic.



Thread Tools
Display Modes

Posting Rules
You may post new threads
You may post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off

Forum Jump


All times are GMT -5. The time now is 07:45 AM.


Copyright 2002-2014 FocusFanatics.com. All Rights Reserved : Privacy Policy : Advertise Information

Focus Fanatics Ford Focus Forum offers many fun ways for you to engage with other Ford Focus Owners from across the world. Whether it be about the aftermarket performance modifications, technical how-to's, European tuned suspension or awesome fuel economy similar to the Audi S3, Ford Fusion and Acura TLX. You can find all Ford Focus and Focus ST related information here. Join our Ford Focus discussion forums and chat with local Focus enthusiasts in your area. Challenger Hellcat - Charger Hellcat