Thermostat location?

[Griblik]

Every time I try on work on my truck, I get a reminder of just how completely lost I am in my own engine compartment... Where the heck is the thermostat on my 7.3 IDI? Thanks guys.

 

[The Warden]

If you look at your radiator, find the hose that goes from the top of the radiator to the engine. On the engine, the hose goes into a cast piece that makes up the hose nipple. This cast piece is also the thermostat housing.

You pretty much need to remove the alternator to get to the bolts to remove the housing to get to the thermostat. I can't remember if you need to remove the fuel filter mounting bracket or not, but you may need to.

Take a look at the picture I attached...gives you an idea of where exactly the thermostat is located, with everything removed (was in the process of putting the engine back together when I took that picture, and hadn't done any of the accessories yet).

Hope this helps...good luck!

 

[Griblik]

That's what I needed! Thanks a lot. Happy T-Day.

 

[estirpe]

If you look at your radiator, find the hose that goes from the top of the radiator to the engine. On the engine, the hose goes into a cast piece that makes up the hose nipple. This cast piece is also the thermostat housing.

You pretty much need to remove the alternator to get to the bolts to remove the housing to get to the thermostat. I can't remember if you need to remove the fuel filter mounting bracket or not, but you may need to.

Take a look at the picture I attached...gives you an idea of where exactly the thermostat is located, with everything removed (was in the process of putting the engine back together when I took that picture, and hadn't done any of the accessories yet).

Hope this helps...good luck!

I removed the alternator and I cannot see the bottom bolt, do I have remove the fuel filter mounting bracket as well????

 

[IDIeselman]

Just in case.

02-21-2006, 03:05 PM #14
OkieGringo
OkieGringo aka Baja



Join Date: Dec 2005
Location: Claremore, Oklahoma
Posts: 395


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Newbie diesel owners often try to replace the thermostat with a gasser type. WRONG THING TO DO!!!! Use ONLY one of the following...
Motorcraft E5TZ-8575-C or Navistar 1807945-C1 thermostat
Also thermostat number 1807974c94 is the current updated part #.

CAUTION:

The specified thermostat does not contain an internal bypass,
since the bypass is located in the cylinder block.
Whenever the thermostat is replaced, it is mandatory that only
Motorcraft E5TZ-8575-C or Navistar 1807945-C1 thermostat
be installed. F*rd comes with gasket for $20.

CAUTION:

Do not attempt to repair the thermostat.
It should be replaced if it is not operating properly.
Check the new thermostat before installing it for
correct opening temperature. Before suspending in
boiling water, with a flashlight check where the
rubber and the flat metal flange meet for bad seal.
Tstat starts opening barely at 180-192f, fully open 200-212f.

The check ball allows air to escape from the block while holding back A/F flow until the tstat opens.

The little steel ball in the upper thermostat housing. Clean out the cavity that the ball sits in. There is a cork o-ring or rubber o-ring, on the surface that mates with the block, that holds the ball in there. Be very careful not to damage it. There should be an opening into the upper neck area. As I understand it, the normal pressure of coolant flow will push the steel ball up to block off the opening into the upper neck, but if the engine is off the ball will drop but still allow any trapped air to escape thru the upper neck area.
The cavity where the ball is was VERY corroded on mine, but I lived in Baja at the time. So I used Dremel to clean up the cavity and find the ball. And used JB Weld to reform the opening to the upper neck. After cleaning, the opening was big enough to allow the ball to escape, thus the need for the JB. If the steel ball is missing, You can order the whole upper housing at A/P store for around $45.00 or try to find a STAINLESS STEEL 1/4" ball on the internet. If the passage is blocked it will not allow trapped air to escape and "hot spots" will develop in the block and can cause overheating. OkieGringo

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Last edited by OkieGringo : 02-21-2006 at