4.6L (1996-2004 Modular) Mustang Technical discussions on 1996-2004 4.6 Liter Modular Motors (2V and 4V) within.

Coolant leak at thermostat housing

Old 04-22-2004, 04:38 PM
  #1  
USAMuscle
4th Gear Member
Thread Starter
 
USAMuscle's Avatar
 
Join Date: Sep 2003
Location: United States
Posts: 1,404
Default Coolant leak at thermostat housing

OK so I have a little coolant leaking out where the thermostat housing mounts to the intake, so I pulled the housing off to take a look, and it looks to me like there's no gasket there at all, so I'm wondering if there was a gasket there to begin with. Does anybody know if there should be a gasket there? I went to the auto parts store and they said they didn't have a gasket, just the O-ring which the thermostat itself sits on, so that led me to believe that maybe there is no gasket for the housing. I tried a little bit of RTV silicon sealer around the base of the housing but it didn't work because it's still leaking. There is a nice little puddle of coolant in the valley pan of the engine and streaks all down the timing cover which is [:'(]. Any ideas??
USAMuscle is offline  
Old 04-22-2004, 05:42 PM
  #2  
96mustanggt46
2nd Gear Member
 
96mustanggt46's Avatar
 
Join Date: Jan 2004
Location: United States
Posts: 235
Default RE: Coolant leak at thermostat housing

Their is no gasket that goes there just an o ring. i would check to see if there is a crack anywhere in the plastick. other than that i don't know.
96mustanggt46 is offline  
Old 04-22-2004, 11:51 PM
  #3  
MelloYello
4th Gear Member
 
MelloYello's Avatar
 
Join Date: Dec 2003
Location: NM
Posts: 1,039
Default RE: Coolant leak at thermostat housing

check your thermostat, it might not be opening and closing properly.... also check water pump....
ANd no theres no gasket there.... your O ring might be cracked and it also may not be installed right...
MelloYello is offline  
Old 04-22-2004, 11:57 PM
  #4  
Casper98GT
I ♥ Acer
 
Casper98GT's Avatar
 
Join Date: Mar 2004
Location:
Posts: 2,287
Default RE: Coolant leak at thermostat housing

What year? And if there is a puddle in the intake area, you might have a crack. Because if you have put RVT on it and still leaks, maybe its not the thermostat
Casper98GT is offline  
Old 04-23-2004, 03:29 AM
  #5  
USAMuscle
4th Gear Member
Thread Starter
 
USAMuscle's Avatar
 
Join Date: Sep 2003
Location: United States
Posts: 1,404
Default RE: Coolant leak at thermostat housing

It's a '96, and I know it's the thermostat housing that is leaking because for one you can see where it's leaked all down the timing cover on the front of the engine, and the coolant pools up in the valley pan because of the way the intake is molded, the coolant runs down the back of the thermostat housing mount right into the valley pan. Also I watched it while the car was running and you can see it bubbling up between the thermostat housing and the intake. Ford and their ****in' plastic intake idea...[:@]
USAMuscle is offline  
Old 04-29-2004, 01:51 AM
  #6  
ekcruzin
 
ekcruzin's Avatar
 
Join Date: Apr 2004
Posts: 2
Default RE: Coolant leak at thermostat housing

My car is in the garage right now.. pulling the intake off tomorrow and going to find a PI intake ASAP. I had the SAME EXACT problem as you just this week. I even went as far as buying a new thermostat, O-ring, and the metal piece that fits over the thermostat. And just as the above posts state, there is no gasket. There is just the o-ring that sits on top of the thermostat. Hope this helped you

Edit: Since you have to buy a new intake, definately go for a '99-up. In '02 they started using one with a metal crossover (the piece that is cracked on ours). I've been looking on several boards and they seem to be running about 130 with shipping included.
ekcruzin is offline  
Old 04-29-2004, 09:23 PM
  #7  
Jay72
I ♥ Acer
 
Jay72's Avatar
 
Join Date: Apr 2003
Location: Im GM Trash.
Posts: 78
Default RE: Coolant leak at thermostat housing

just the O-ring which the thermostat itself sits on
Thats wrong, the thermostat goes in, then the o ring, the thermostat housing sets right on the o ring.
If it's the stock original intake chances are good it's cracked.
Jay72 is offline  
Old 04-29-2004, 11:14 PM
  #8  
USAMuscle
4th Gear Member
Thread Starter
 
USAMuscle's Avatar
 
Join Date: Sep 2003
Location: United States
Posts: 1,404
Default RE: Coolant leak at thermostat housing

Yeah I figure it's probably cracked after reading a few posts on another forum. I'm just going to spring for a PI intake with aluminum cross-over since I'm planning on getting some PI heads this summer. The PI intake alone on NPI heads will gain between 15-20 rwhp according to actual numbers posted by others who have done it, so that's cool.

Oh, and FYI, the thermostat does sit on an orange O-ring inside the water passage, but I wasn't sure if there was supposed to be an O-ring for the housing.
USAMuscle is offline  
Old 04-30-2004, 02:21 PM
  #9  
GiddiupStang
1st Gear Member
 
GiddiupStang's Avatar
 
Join Date: Apr 2004
Location:
Posts: 60
Default RE: Coolant leak at thermostat housing

Will a 99&up 4.6L intake fit on the 96-98 4.6L ??? I was led to believe that they didn't... I have 102500 miles on a 97 GT and although it's not leaking now I am afraid that it will soon after hearing about others going bad. There's a few new 99 & up intakes on ebay right now for under 500bucks.
GiddiupStang is offline  
Old 04-30-2004, 04:08 PM
  #10  
USAMuscle
4th Gear Member
Thread Starter
 
USAMuscle's Avatar
 
Join Date: Sep 2003
Location: United States
Posts: 1,404
Default RE: Coolant leak at thermostat housing

Yes it will fit, and it's an easy swap. The '99+ intakes have longer intake runners which increases torque, and I read a post on stangnet.com forums about somebody who did it, expecting a 15 rwhp gain, and he gained 17 rwhp, and about 17-20 ft. lbs. of torque. Just MAKE SURE whichever intake you get has the aluminum crossover! Otherwise you've just shot yourself in the foot. [:-]
USAMuscle is offline  

Thread Tools
Search this Thread
Quick Reply: Coolant leak at thermostat housing



All times are GMT -5. The time now is 07:32 AM.