Notices
1980 - 1986 Bullnose F100, F150 & Larger F-Series Trucks Discuss the Early Eighties Bullnose Ford Truck

Identify this part please

Thread Tools
 
Search this Thread
 
Old Jan 12, 2021 | 10:41 PM
  #1  
Ismaelx's Avatar
Ismaelx
Thread Starter
|
Trailering
Joined: Sep 2018
Posts: 23
Likes: 2
From: SoCal
Question Identify this part please


This hose with the valve like thing in the middle was connected to big port in the PCV Valve and other end in manifold vacuum under EGR spacer, What is it? is there the correct conection?
 
Reply
Old Jan 12, 2021 | 10:44 PM
  #2  
Ismaelx's Avatar
Ismaelx
Thread Starter
|
Trailering
Joined: Sep 2018
Posts: 23
Likes: 2
From: SoCal
Forgot to mention the truck , 1981 F-150 Ranger I6 4.9l/300
 
Reply
Old Jan 13, 2021 | 03:45 AM
  #3  
FuzzFace2's Avatar
FuzzFace2
FTE Legend
10 Year Member
Photogenic
Community Builder
Liked
Joined: Nov 2015
Posts: 30,935
Likes: 4,124
From: Angier, NC
Club FTE Gold Member
Think someone said it was a hot air compensator.
IIRC it causes a vacuum leak that raises the idle speed so the fan spins faster cooling the motor.
I have only seen them on 460 motors. Is yours a CA emissions truck?
Dave ----
 
Reply
Old Jan 13, 2021 | 10:18 AM
  #4  
kr98664's Avatar
kr98664
Lead Driver
10 Year Member
Liked
Loved
Community Favorite
Joined: Nov 2013
Posts: 7,178
Likes: 1,174
Originally Posted by FuzzFace2
Think someone said it was a hot air compensator.
IIRC it causes a vacuum leak that raises the idle speed so the fan spins faster cooling the motor.
Interesting. That looks like a bimetallic element on the top, and probably "uncorks" the port at the top of the body when hot.

Curious that it would operate based on underhood temperature. Seems that value would be all over the place, influenced by road speed, engine load, etc. Compare that to something like coolant temperature, which would be much more uniform.
 
Reply
Old Jan 13, 2021 | 10:53 AM
  #5  
1986F150six's Avatar
1986F150six
Lead Driver
Joined: Jul 2009
Posts: 6,477
Likes: 19
From: Sheffield, AL
Old Jan 13, 2021 | 11:21 AM
  #6  
FuzzFace2's Avatar
FuzzFace2
FTE Legend
10 Year Member
Photogenic
Community Builder
Liked
Joined: Nov 2015
Posts: 30,935
Likes: 4,124
From: Angier, NC
Club FTE Gold Member
Do I need it
That is a good question.

Do we know when its to work and what / why it's to do?

The way I see it if it is not causing a vacuum leak just sitting there and only when it is saposto then what's the harm in leaving it?
Dave ----
 
Reply
Old Jan 13, 2021 | 11:25 AM
  #7  
kr98664's Avatar
kr98664
Lead Driver
10 Year Member
Liked
Loved
Community Favorite
Joined: Nov 2013
Posts: 7,178
Likes: 1,174

Great info! Found this link in there, lots of details here:

Hot Idle Compensator Valve


https://secure.cougarpartscatalog.co...mpensator.html


From the last link:

"When the ambient under hood temp increases to a certain point the bi-metallic strip on the hot idle compensator opens a rubber needle - brass seat metered orifice, causing what is essentially a vacuum leak of a predetermined amount into the intake system. This extra air will in turn cause the idle speed to increase, moving more air through the radiator and water through the cooling system due to increased fan and water pump speed the result being the motor will cool down to the point where the ambient under-hood temp is lower, and the valve closes and the vacuum leak will stop, returning the engine to a normal idle speed.This cycle repeats itself over and over. Obviously this will only help during periods of engine idle. Remember, this was engineered in the early sixties and in theory is workable. What normally happened is that IF the little rubber needle valve did lift from the brass seat and cause the idle to increase, it sometimes would not seat properly when cooler, and caused an erratic idle. Most were tossed in the garbage back in the day. In the real world, this little device probably caused more problems than it solved! It had a somewhat short life, was kind of a band-aid fix, and was replaced with a bigger and better cooling system as more and more Ford products were sold with factory A/C."


 
Attached Files
File Type: html
HICV_4180C_001.jpg.html (16.7 KB, 12 views)
Reply
Old Jan 13, 2021 | 11:27 AM
  #8  
Ismaelx's Avatar
Ismaelx
Thread Starter
|
Trailering
Joined: Sep 2018
Posts: 23
Likes: 2
From: SoCal
Originally Posted by FuzzFace2
Think someone said it was a hot air compensator.
IIRC it causes a vacuum leak that raises the idle speed so the fan spins faster cooling the motor.
I have only seen them on 460 motors. Is yours a CA emissions truck?
Dave ----
Yes, I'm in beautiful California
 
Reply
FTE Stories

Ford Trucks for Ford Truck Enthusiasts

story-0

Top 10 Fords at 2026 Carlisle Ford Nationals

 Joe Kucinski
story-1

3 Best / 3 Worst Parts of Modern Ford Ownership

 Brett Foote
story-2

10 Amazing Upgrades That Solve Common Ford Truck Owner Headaches

 Pouria Savadkouei
story-3

Every 2026 Ford Engine Explained

 Brett Foote
story-4

10 Ugly Ford Trucks That We Still Kinda Love

 Joe Kucinski
story-5

10 Things Every Truck Owner NEEDS (2026 Edition)

 Michael S. Palmer
story-6

Rezvani's Latest Post-Apocalyptic Monster Is a Ford F-150 Raptor Underneath

 Verdad Gallardo
story-7

Top 10 Most Expensive Ford Trucks Ever Sold on Bring a Trailer

 Joe Kucinski
story-8

2027 Ford Super Duty Buyer's Guide (Every Model, Engine, & Package)

 Brett Foote
story-9

Top 10 Ford Truck Tragedies

 Joe Kucinski
Old Jan 13, 2021 | 11:30 AM
  #9  
Ismaelx's Avatar
Ismaelx
Thread Starter
|
Trailering
Joined: Sep 2018
Posts: 23
Likes: 2
From: SoCal
Originally Posted by kr98664
Interesting. That looks like a bimetallic element on the top, and probably "uncorks" the port at the top of the body when hot.

Curious that it would operate based on underhood temperature. Seems that value would be all over the place, influenced by road speed, engine load, etc. Compare that to something like coolant temperature, which would be much more uniform.
Yes, if you pull the top part it opens.
 
Reply
Old Jan 13, 2021 | 12:25 PM
  #10  
Ismaelx's Avatar
Ismaelx
Thread Starter
|
Trailering
Joined: Sep 2018
Posts: 23
Likes: 2
From: SoCal
Well, now that I know the name of this thing "hot idle compensator valve" I have found some more information about it and appears that it was in the right place according to information from the page mentioned in above link provided by kr98664 "It is installed in the middle of the hose that connects the PCV valve to the rear of the carburetor spacer."
The question now is, should I leave it in place or remove it? I'm putting back together intake/exhaust manifold, carb, egr, changing all vacuum lines, etc. If I put it back I'll be closely monitoring it for possible malfunction.
I purchased this truck about a couple months ago, it's pretty straight, the truck sat for about 20 years, it was running and I drove it around the block but was running really rich, lots of vacuum leaks, but this hot idle compensator valve looks in great shape. thank you to everybody for your input.
 
Reply
Old Jan 13, 2021 | 05:46 PM
  #11  
FuzzFace2's Avatar
FuzzFace2
FTE Legend
10 Year Member
Photogenic
Community Builder
Liked
Joined: Nov 2015
Posts: 30,935
Likes: 4,124
From: Angier, NC
Club FTE Gold Member
Originally Posted by Ismaelx
Yes, I'm in beautiful California
If so then what can you remove and still pass your smog test?
That valve may be on the CARB list as needing to be in place?
Just my .02
Dave ----
 
Reply
Old Jan 13, 2021 | 07:01 PM
  #12  
matthewq4b's Avatar
matthewq4b
Post Fiend
Joined: Feb 2008
Posts: 5,831
Likes: 121
From: St Albert, Alberta
Originally Posted by Ismaelx
Well, now that I know the name of this thing "hot idle compensator valve" I have found some more information about it and appears that it was in the right place according to information from the page mentioned in above link provided by kr98664 "It is installed in the middle of the hose that connects the PCV valve to the rear of the carburetor spacer."
The question now is, should I leave it in place or remove it? I'm putting back together intake/exhaust manifold, carb, egr, changing all vacuum lines, etc. If I put it back I'll be closely monitoring it for possible malfunction.
I purchased this truck about a couple months ago, it's pretty straight, the truck sat for about 20 years, it was running and I drove it around the block but was running really rich, lots of vacuum leaks, but this hot idle compensator valve looks in great shape. thank you to everybody for your input.

Just leave it in place it is not hurting anything and may help prevent hot idle stumbles. If your truck is A/C equipped then definitely leave it in place. They are pretty much bulletproof and basically never fail. And are far more reliable than the throttle kickers or the VCVs that replaced them.
 
Reply
Old Jan 14, 2021 | 01:21 AM
  #13  
Ismaelx's Avatar
Ismaelx
Thread Starter
|
Trailering
Joined: Sep 2018
Posts: 23
Likes: 2
From: SoCal
yes it looks like this valve it's in great shape, I'm going to leave it in place. That's true, it my be in the CARB list.
As I mentioned above, I'm replacing all vacuum lines, does anybody know where I can find the filters that insert in the vacuum control valve or thermal ported vacuum switch?
 
Reply
Related Topics
Thread
Thread Starter
Forum
Replies
Last Post
aroberson
1987 - 1996 F150 & Larger F-Series Trucks
4
Apr 5, 2016 02:04 PM
Dagf100project
1987 - 1996 F150 & Larger F-Series Trucks
29
Aug 12, 2015 04:30 PM
Finger__Rachet
1987 - 1996 F150 & Larger F-Series Trucks
23
Sep 14, 2013 04:38 PM
PAULAU123
Small Block V8 (221, 260, 289, 5.0/302, 5.8/351W)
10
Sep 16, 2011 08:20 PM
whatstar1117
Aerostar
9
May 14, 2008 01:24 AM




All times are GMT -5. The time now is 06:03 AM.

story-0
Top 10 Fords at 2026 Carlisle Ford Nationals

Slideshow: Top 10 Fords at 2026 Ford Nationals

By Joe Kucinski | 2026-06-09 11:10:08


VIEW MORE
story-1
3 Best / 3 Worst Parts of Modern Ford Ownership

Based on years of owning multiple modern Ford products.

By Brett Foote | 2026-06-09 10:53:36


VIEW MORE
story-2
10 Amazing Upgrades That Solve Common Ford Truck Owner Headaches

SPONSORED: From muddy boots to rain-soaked cargo, these upgrades address some of the most common frustrations Ford truck owners face every day.

By Pouria Savadkouei | 2026-06-08 18:50:34


VIEW MORE
story-3
Every 2026 Ford Engine Explained

Here's everything you need to know about every Ford engine available for the 2026 model year.

By Brett Foote | 2026-06-05 12:58:01


VIEW MORE
story-4
10 Ugly Ford Trucks That We Still Kinda Love

Slideshow: 10 ugly Ford trucks that we still kinda love.

By Joe Kucinski | 2026-06-03 09:51:16


VIEW MORE
story-5
10 Things Every Truck Owner NEEDS (2026 Edition)

Slideshow: the best gifts for dads & grads

By Michael S. Palmer | 2026-06-03 15:43:58


VIEW MORE
story-6
Rezvani's Latest Post-Apocalyptic Monster Is a Ford F-150 Raptor Underneath

Slideshow: Called the Fortress, the 850-horsepower pickup combines Raptor underpinnings with military-inspired features, survival equipment, and a starting price of $285,000.

By Verdad Gallardo | 2026-06-03 11:38:36


VIEW MORE
story-7
Top 10 Most Expensive Ford Trucks Ever Sold on Bring a Trailer

Slideshow: 10 most expensive Ford trucks ever sold on Bring a Trailer.

By Joe Kucinski | 2026-05-27 16:24:34


VIEW MORE
story-8
2027 Ford Super Duty Buyer's Guide (Every Model, Engine, & Package)

Here's everything that has changed for the latest model year.

By Brett Foote | 2026-05-27 16:17:28


VIEW MORE
story-9
Top 10 Ford Truck Tragedies

Slideshow: Top 10 Ford truck tragedies.

By Joe Kucinski | 2026-05-18 19:34:33


VIEW MORE