Bad thermostat, weird idle and MPG - Ford Focus Forum, Ford Focus ST Forum
Ford Focus Forum
HomeContact UsAbout UsGalleryDiscussion ForumsMarketplace

Go Back   Ford Focus Forum, Ford Focus ST 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

Thread Tools Display Modes
Old 12-03-2012, 11:52 AM   #1
Focus Enthusiast
Join Date: Oct 2012
Fan#: 105414
Location: Olympia, WA
What I Drive: '05 Silver ST

Posts: 68
FF Reputation: 1 bones33 Good Standing Member
Buy-Sell-Trade Rating: (0)
Bad thermostat, weird idle and MPG

Just though I'd post this for those interested.

My '05 ST with 2.3 was purchased with a bad thermostat (stuck open). It warmed up according to the gauge in just a couple of miles from cold. It ran well except for an inconsistently high idle, no CEL. The heater put out warm, not really hot air. MPG was ranging from 27-30.

I plugged in the scangauge to get an idea of the temps the PCM was seeing. Turns out that when the gauge reads normal, it doesn't change from 143* to at least 215* which is as hot as it ever got. Often it would run between 150* and 175*. Again, the in-dash gauge always read the same and indicating "normal".

Changed thermostat.

Now it warms up much faster, heater is toasty hot and maintains at least 195* per the specs. Idle is rock solid and consistent. MPGs now are consistently just over 33 in the last 3 tanks.

bones33 is offline  
    Reply With Quote

Bookmarks & Social Networks
Thread Tools
Display Modes

Posting Rules
You may not post new threads
You may not 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 08:15 PM.

Copyright 2002-2014 All Rights Reserved : Terms of Use : 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 Acura TLX or Fiesta ST. 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.