Thermostat Replacement On the 3.4 V6 Engine - 3rd Gen 4Runner - YotaTech Forums
YotaTech Forums  

Go Back   YotaTech Forums > Tech Write-Ups (Staging Area & More Articles In The Wiki) > Maintenance & Repair

Maintenance & Repair Care and feeding of your rig

Thermostat Replacement On the 3.4 V6 Engine - 3rd Gen 4Runner

Closed Thread
LinkBack Thread Tools Search this Thread
Old 01-14-2006, 08:33 PM   #1
Registered User
Personal Sales Rating: (0)
Join Date: May 2002
Location: Los Angeles
Posts: 10,036
Thermostat Replacement On the 3.4 V6 Engine - 3rd Gen 4Runner

Thermostat Replacement On the 3.4 V6 Engine - 3rd Gen 4Runner
By HaveBlue

HaveBlue shows you how he replaced his thermostat.

Items you will need:
Thermostat gasket
1 gallon coolant (Toyota long-life is recommended)
1 gallon distilled water
Empty one or two gallon container
Bucket or container to catch old coolant (minimum 2.5 gallon capacity)
Metric sockets (12mm, 17mm)
3/8 drive ratchet w/ 6 extension

If you have the TRD Supercharger with Dynamic Belt Tensioner, you will need to follow these instructions. If you do not have the Dynamic Belt Tensioner, you can skip ahead to step 5. Skid plate removal is not necessary, but it does allow for easier access to the lower radiator hose and drain valve.

1. Remove the radiator cap.

2. Locate the drain valve on the bottom of the radiator.

Click the image to open in full size.

This is where it is beneficial to have the skid plate removed. Open the valve fully. Pliers may be required to break the seal and loosen the valve. Have your container ready to catch all the coolant as it drains.

3. Using a 3/8 ratchet, pull the Dynamic Belt Tensioner away from the belt and remove the belt from the supercharger pulley.

Click the image to open in full size.

4. Using a 17mm wrench or socket, remove the bolt holding the belt tensioner and remove the tensioner.

Click the image to open in full size.

5. After the coolant has stopped draining from the radiator valve, use a pair of adjustable pliers to move the spring clamp away from the radiator on the lower radiator hose. Pull the lower radiator hose away from the radiator. The pliers may need to be used to twist the hose and break the seal. Have a rag or container ready to catch the spilled coolant.

6. Use the 12mm socket and 6 extension to remove the three nuts holding the thermostat housing in place.

Click the image to open in full size.

7. Place a rag under the thermostat housing and pull the housing away from the block.

8. Note the position of the jiggle valve (brass button). The new thermostat will need to be installed with the jiggle valve in the same location. Use a flat screwdriver to pry the old thermostat out of the block and be prepared for more coolant to spill out.

9. Clean out the housing and the block. Make sure you remove all remaining gasket material.

10. Apply the new gasket around the new thermostat. The gasket should have a groove that will fit around the outer edge of the thermostat.

11. Place the new thermostat in the block with the jiggle valve in the same location as the old thermostat. For reference, the jiggle valve should be within 15 degrees of the 12 o'clock position. Make sure the thermostat is seated and snug.

12. Place the thermostat housing on the three studs and secure it with the three nuts. DO NOT over tighten! The housing can fracture if over tightened. The torque setting on the nuts should not exceed 14 ft/lbs.

13. Secure the lower radiator hose to the radiator and seat the spring clamp on the hose.

14. Close the radiator drain valve completely.

If you have the Dynamic Belt Tensioner, use the following steps. Otherwise, skip to step 17.
15. Reinstall the belt tensioner.

16. Reinstall the belt under the tensioner and around the supercharger pulley. Make sure the drive belt is seated on the alternator pulley, supercharger pulley, and crank pulley.

17. Refill the radiator with 50/50 coolant (50% glycol, 50% water).

18. Leave the radiator cap off and start the engine. Let the engine come to normal temperature and turn the heater on. This will purge the system of any air that might be trapped within the system.

19. Fill the overflow reservoir about halfway with 50/50 coolant.

20. Continue to fill the radiator if the fluid level drops. Once it has stopped dropping, screw the radiator cap back into place and take it for a drive.

Last edited by Bob_98SR5; 01-14-2006 at 08:34 PM.
Bob_98SR5 is offline  
Closed Thread

Similar Threads
Thread Thread Starter Forum Replies Last Post
New member fighting a 3vze--idle, timing, mixture Blamalam 86-95 Trucks & 4Runners 16 09-26-2015 08:16 AM
Flying91's 1991 4runner LOWEST SAS 30" tires Flying91 86-95 Trucks & 4Runners (Build-Up Section) 12 09-08-2015 02:39 PM
4runner build ChiefTetlow 95.5-2004 Tacomas & 96-2002 4Runners (Build-Up Section) 1 08-10-2015 04:19 AM
AC Cut relay ghostmoney 86-95 Trucks & 4Runners 3 08-06-2015 08:40 AM
3.4 swaps 93toyoguy Newbie Tech Section 10 08-02-2015 07:41 PM

2000, 34, 4runner, 88, capacity, housing, motor, radiator, replace, replacement, replacing, runner, thermostat, therostat, thurmostat, toyota, v6

Thread Tools Search this Thread
Search this Thread:

Advanced Search

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
Trackbacks are Off
Pingbacks are Off
Refbacks are Off

All times are GMT -8. The time now is 12:56 AM.

2010 InternetBrands, Inc.