Notices
86-95 Trucks & 4Runners 2nd/3rd gen pickups, and 1st/2nd gen 4Runners with IFS
Sponsored by:
Sponsored by: DashLynx

Overheating question

Thread Tools
 
Search this Thread
 
Old 12-10-2015, 09:12 PM
  #1  
Registered User
Thread Starter
 
Cde5's Avatar
 
Join Date: Dec 2015
Posts: 2
Likes: 0
Received 0 Likes on 0 Posts
Overheating question

I have a 94 pickup 3.0 V6. It has started overheating when idling with the heater on. Once I start driving it quickly drops back to normal. It has never got into the red area, but really close. Would this be a thermostat issue? Any help would be appreciated it. Thanks
Old 12-10-2015, 09:50 PM
  #2  
Super Moderator
Staff
iTrader: (1)
 
Terrys87's Avatar
 
Join Date: Aug 2008
Location: Anderson Missouri
Posts: 11,788
Likes: 0
Received 21 Likes on 19 Posts
My past experiece with your situation is a dirty/clogged radiator. Not enough air is moving to cool the fluid. I would go thru the entire cooling system.
Old 12-13-2015, 12:53 PM
  #3  
Registered User
 
JJ'89's Avatar
 
Join Date: Aug 2007
Location: Fresno
Posts: 323
Received 50 Likes on 40 Posts
Originally Posted by Cde5
I have a 94 pickup 3.0 V6. It has started overheating when idling with the heater on. Once I start driving it quickly drops back to normal. It has never got into the red area, but really close. Would this be a thermostat issue? Any help would be appreciated it. Thanks
Not a thermostat problem. If it was thermostat, it would overheat while moving too. Driving = moving = ram air flowing through the radiator. Idling = no ram air. Not moving depends upon the cooling system belt-driven fan to move air through the heat exchanger (radiator). There is a device that couples the fan to the shaft that rotates it. This device slips under some conditions (speed and temperature). It tends to to lock-up at lower engine speeds and higher temperatures. Simple explanation of the system. Your "fan clutch" probably needs to be replaced. Simple job. I'd buy a genuine Toyota part if I would be doing the job on my truck. Parts store replacements are probably considerably cheaper though. My $0.02
simple on a 22RE, I don't have experience with the V-6.

Last edited by JJ'89; 12-13-2015 at 12:56 PM.
Old 12-13-2015, 08:40 PM
  #4  
ZUK
Registered User
iTrader: (1)
 
ZUK's Avatar
 
Join Date: Oct 2003
Location: Prescott AZ
Posts: 1,845
Received 24 Likes on 22 Posts
Originally Posted by Cde5
I have a 94 pickup 3.0 V6. It has started overheating when idling with the heater on. Once I start driving it quickly drops back to normal. It has never got into the red area, but really close. Would this be a thermostat issue? Any help would be appreciated it. Thanks
air flow issue....
Is the fan shroud still in place? Is the plastic fan even turning?
Old 12-14-2015, 07:37 PM
  #5  
Registered User
Thread Starter
 
Cde5's Avatar
 
Join Date: Dec 2015
Posts: 2
Likes: 0
Received 0 Likes on 0 Posts
Originally Posted by ZUK
air flow issue....
Is the fan shroud still in place? Is the plastic fan even turning?
Yes the fan is turning. What is the fan shroud? Thx
Old 12-15-2015, 08:25 AM
  #6  
Registered User
 
Janos01's Avatar
 
Join Date: Jul 2014
Location: Dallas, TX
Posts: 360
Likes: 0
Received 0 Likes on 0 Posts
Originally Posted by Cde5
Yes the fan is turning. What is the fan shroud? Thx
Its a plastic cover above the fan to protect it and you when in operation.
Old 12-15-2015, 08:34 AM
  #7  
Registered User
 
scope103's Avatar
 
Join Date: Sep 2007
Location: San Francisco East Bay
Posts: 8,254
Likes: 0
Received 822 Likes on 649 Posts
Here's a drawing (second page) http://web.archive.org/web/201311071...11radiator.pdf

The "no. 2" shroud (the thin strip at the bottom) isn't TOO critical, but if the rest of the shroud is missing I would expect the problem you're having.

The fan clutch will spin the fan even when it's hot and "disengaged," but it may not spin it fast enough. With the engine off and the clutch cold, it should feel "pretty stiff." Replacing the clutch is a pretty simple job, but the part is $170-$250 online http://www.toyotapartsoverstock.com/...621065030.html
Amazon.com: Toyota 16210-65030 Engine Cooling Fan Clutch: Automotive Amazon.com: Toyota 16210-65030 Engine Cooling Fan Clutch: Automotive
, probably around $300 at your brick-and-mortar dealership. A little steep, in my book, to replace on a guess.

I've never seen an "aftermarket" fan clutch, so if you find one let us know.
Old 12-15-2015, 09:34 AM
  #8  
Registered User
 
JJ'89's Avatar
 
Join Date: Aug 2007
Location: Fresno
Posts: 323
Received 50 Likes on 40 Posts
Originally Posted by scope103
Here's a drawing (second page) http://web.archive.org/web/201311071...11radiator.pdf

The "no. 2" shroud (the thin strip at the bottom) isn't TOO critical, but if the rest of the shroud is missing I would expect the problem you're having.

The fan clutch will spin the fan even when it's hot and "disengaged," but it may not spin it fast enough. With the engine off and the clutch cold, it should feel "pretty stiff." Replacing the clutch is a pretty simple job, but the part is $170-$250 online http://www.toyotapartsoverstock.com/...621065030.html Amazon.com: Toyota 16210-65030 Engine Cooling Fan Clutch: Automotive, probably around $300 at your brick-and-mortar dealership. A little steep, in my book, to replace on a guess.

I've never seen an "aftermarket" fan clutch, so if you find one let us know.
rockauto.com Toyota -- 1994 -- pickup -- 3.0l V8 -- cooling system -- radiator fan clutch

take your pick. There's not an easy way to check one of these, but if its not sucking air strongly through the radiator while vehicle static, engine idling, and temp indicator out of the green and rising...it ain't no good. Use a piece of paper or light cardboard at the face of the radiator. How to select among the offerings on rockauto? List 'em here, and the cognoscenti will let you know. My $0.02
Old 12-18-2015, 11:04 AM
  #9  
Registered User
 
RAD4Runner's Avatar
 
Join Date: Mar 2012
Posts: 7,080
Received 663 Likes on 455 Posts
I concur on possibility of fan bad clutch.
Ensure that shroud is in good condition. This will ensure that airflow from fan is focused on the radiator and that heat from the radiator is focused on and is sensed by the fluid coupling (fan clutch).
Then observe how closely the fan follows engine/pulley speed.
Here's how I did mine... After stopping from a drive at operating temperature, I let engine idle for 5 minutes. This helps ensure that forced/ram air from highway speed is no longer cooling the fan clutch.
Turned engine off and counted number of seconds until fan also stops. Fan stopped about 2 seconds after engine stopped. This is on a new fan clutch.
Bad fan clutch with weaker coupling would stop later. [YOUTUBE]
[/YOUTUBE]

BELOW IS EXAMPLE OF BAD FAN CLUTCH WHEN FAN CLUTCH IS HOT
[YOUTUBE]
[/YOUTUBE]

Last edited by RAD4Runner; 12-18-2015 at 11:16 AM.
Related Topics
Thread
Thread Starter
Forum
Replies
Last Post
Sherrie Myers
Newbie Tech Section
3
06-08-2016 01:56 PM
jjrbus
86-95 Trucks & 4Runners
11
10-22-2015 09:09 PM
Ronnyboy
86-95 Trucks & 4Runners
9
10-13-2015 02:15 AM
Keith Lloyd
86-95 Trucks & 4Runners
4
10-08-2015 05:35 PM
Jdgarrison
86-95 Trucks & 4Runners
1
10-01-2015 05:22 PM



Quick Reply: Overheating question



All times are GMT -8. The time now is 02:39 PM.