replacing thermostat - Defender Source
Defender Source  

Go Back   Defender Source > Defender & Series Technical Discussions > Defender Technical Discussions


Reply
 
Thread Tools
  #1  
Old August 28th, 2004, 02:51 PM
jstrong98's Avatar
jstrong98
Status: Offline
Jon Strong
Member
 
Join Date: Mar 2004
Location: Pennsville NJ USA
Posts: 98
replacing thermostat

Over heated yesterday just as I pulled into my garage, vent cap on the overflow resivior popped and was spewing steam and coolant. Just finished about a 12 mile drive, around 45-50 mph, no wheelin or tough driving. I didn't notice that the truck was hot until I saw the steam, and then saw the temp gauge nearin the orange line. I immediately shut the truck down, opened the hood, and tried to assess what had gone wrong. First thought I'd blewn a hose due to the ammount and sudden appearance of the steam, but looked for leaks every where, and the only source was the overlfow resv.

I've read all the over heat symptoms in the FAQ, checked the fan coupling, belts, clamps ,hoses, and the water pump is doesn't appear to have any leaks, and I have had no indications that there were any other fluid leaks. I had just done an oil change and air filter change that AM. Oil levels check OK, and no foam or indications of coolant in the oil on the dipstick.

The truck has run fine since I bought it in March this year, so I am taking a shot that its most likely a bad thermostat. This will be my first "repair" to the D-90 other than routine maint. I've done this before on other trucks/ cars, but I want to be extra careful with my D-90. Its in great shape, and I dont want to screw anything up.

So, basically I'm looking for anyone whose done this recently to chime in with any tips or precautions. I see that there is a temp sending unit in the top hose "goose-neck" that the thermo sets in. Should I replace this also ? Or is it just for the temp gauge ?

Thanks

Jon.
Reply With Quote
Sponsored Links
Advertisement
 
  #2  
Old August 30th, 2004, 12:24 PM
Mike Hippert's Avatar
Mike Hippert
Status: Offline
D-90Slut/Stalker,SNLPres
94 D-90 Grinding Rover
Member
 
Join Date: Sep 2003
Location: Manchester NH USA
Posts: 4,789
The T-stat is easy, besides the basics you need to make sure that the giggle pin in the T-stat is in the 12 O'Clock position so that any air bubbles in the system can get though when the T-stat is closed. When tightening the bolts that hold the housing on be careful not to go to tight as you are only going into aluminum. And you can check your T-stat by putting it into a pot of water on the stove, when the water reaches about 150*F it should open.

That one wire sender is just for the gauge and the gages have been know to go bad. You could check it by pulling the sensor out of the housing, attaching a ground wire to the side of the sensor and sticking it in a cup of hot water next to a thermometer, the gauge should read about 150*F at the 1/2 way and about 240* at the red. You will have to have the ignition on but the engine off.
__________________
Don't forget to
To view links or images in signatures your post count must be 10 or greater. You currently have 0 posts.
first then ask questions later! The loose nut behind the wheel
Reply With Quote
  #3  
Old August 30th, 2004, 01:32 PM
jstrong98's Avatar
jstrong98
Status: Offline
Jon Strong
Member
 
Join Date: Mar 2004
Location: Pennsville NJ USA
Posts: 98
thanks mike, just pulled the t-stat, no problems, just had to disconnect a few plug wires and move a vacum hose. Going to test the t-stat and make sure its the problem, new t-stat should be here tomorrow.
Reply With Quote
Sponsored Links
Advertisement
 
  #4  
Old May 25th, 2009, 04:53 PM
Gore Ranger's Avatar
Gore Ranger
Status: Offline
Jeff
1989 RRC
Member
 
Join Date: Jan 2006
Location: Denver, CO
Posts: 536
hey guys,

I removed my radiator to flush the whole system and renew the fluid. I also decided to replace my thermostat since I think it was stuck open- it took forever for the vehicle to heat up. anyway, I removed everything a few weeks ago and I forgot which side of the thermostat points in? I know the jiggle pin goes at 12 o'clock, but I am not sure which side points in? In the attached picture, is the orientation of the thermostat correct?

Also, it is very difficult to get the housing back in and have the gasket stay in place. Is there anything wrong with using some black right stuff along with the gasket to get it to stay more easily?

Follow-up Post:

ok, I think that's correct since I read on the web that the spring should be on the block side. Can anyone confirm? I'd like to get this buttoned up...
Attached Thumbnails
Click image for larger version

Name:	P1010057.JPG
Views:	121
Size:	72.7 KB
ID:	19703  
Reply With Quote
  #5  
Old May 25th, 2009, 09:59 PM
JRW's Avatar
JRW
Status: Offline
John
94 D90 ST #1247
Member
 
Join Date: Jun 2008
Location: Flower Mound, TX
Posts: 253
I am thinking out loud, but it would make sense to have the spring on the block side. This is the piece which will heat up and release to open the thermostat...
Reply With Quote
  #6  
Old May 25th, 2009, 10:08 PM
Red90's Avatar
Red90
Status: Online
John B.
1991 Defender 90, 200TDI
Site Team
 
Join Date: Sep 2003
Location: Calgary
Posts: 9,225
Registry
Yes, like that. A little sealer to hold the gasket is fine.
Reply With Quote
Reply

Lower Navigation
Go Back   Defender Source > Defender & Series Technical Discussions > Defender Technical Discussions

Tags
ac, thermostat

Thread Tools

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


Similar Threads
Thread Thread Starter Forum Replies Last Post
Replacing Alt, H20 pump, fan clutch, and belts - Advice needed arbik Defender Technical Discussions 3 January 7th, 2006 09:11 AM
How and Why to add an oil thermostat Hans Misc. Chit-Chat 0 February 18th, 2005 03:57 PM
Installing oil cooler thermostat Doug Defender Technical Discussions 8 February 18th, 2005 12:43 AM
Replacing 4.0 with 4.6 Trevor Tarr Defender Technical Discussions 17 December 15th, 2004 10:21 PM
Questions about replacing hub seals... discobro Defender Technical Discussions 5 June 5th, 2004 12:07 PM


All times are GMT -5. The time now is 11:00 PM.


Copyright