• Welcome Visitor! Please take a few seconds and Register for our forum. Even if you don't want to post, you can still 'Like' and react to posts.

2.8l thermostat issues

ShadowWolf

New Member
Joined
Jan 21, 2014
Messages
18
Reaction score
0
Points
0
Vehicle Year
1984
Make / Model
Ford
Engine Size
2.8L
Transmission
Automatic
I have a 1984 bronco II 2.8l v6 that I recently changed both head gaskets on after loosing a heater core hose (The one that is under the crank). With the thermostat removed the truck cools just fine and can sit there idling all day and barely reach 190 and while driving the temp gauge will sit at the very bottom of the norm range. However, With the thermostat installed the truck quickly shoots up above 190 at the upper housing (The thermostat is in the lower housing). If I drive the truck around a bit and then get out and feel the lower hose it is cold and the top hose is scolding hot, the heater hoses are also very hot. At this point the temp gauge is up at the top of the norm range and the heat is VERY hot, if I check the temp at the upper housing with a laser thermometer I get upwards of 220. Yet there is no circulation in the radiator. I flushed the system out about 4 times and that did not help at all. I'm at a loss as to why the thermostat will not open (the stat is rated at 192 and I checked it by heating a pot of water to 200 and submerging it). Can anyone here help me out with this truck? It was fine until that one hose broke and sadly I was on a section of highway that does not have a pull off. So I was painfully forced to drive it so the closest safe area and by that time I had a heavy knock. Thankfully the engine seems to be ok and I simply had to replace the head gaskets.
 


kimcrwbr1

Well-Known Member
Joined
Dec 6, 2009
Messages
6,044
Reaction score
43
Points
48
Location
maplevalley WA
Vehicle Year
1983
Make / Model
ford
Engine Size
2.8l
Transmission
Automatic
Ever since I put the thermostat in the upper housing I have not had any problems. There is a thermostat housing (two piece) that works on that motor it just may be hard to find. I got lucky one day looking for a egr spacer I stumbled into it. I believe it was a 85 B-2 with air conditioning You will need to remove the thermostat out of the lower housing and plug the bypass fitting on the intake manifold.

This is what it looks like kinna hard to see but the thermostat sits verticle in the housing you would also need to tweak the upper hose unless you can find the correct one plus a 1" by 1" bypass hose.
 

kimcrwbr1

Well-Known Member
Joined
Dec 6, 2009
Messages
6,044
Reaction score
43
Points
48
Location
maplevalley WA
Vehicle Year
1983
Make / Model
ford
Engine Size
2.8l
Transmission
Automatic
If both heater hoses are getting hot you may have a blocked bypass fitting on the intake manifold. Carefully pull the hose off and take a drill and ream the hole out as large as possible without damaging the nipple.
http://www.autozone.com/autozone/parts/Dayco-Hose-Bypass/1984-Ford-Ranger-2WD/_/N-ik8k8Zaptce?itemIdentifier=883074_713747_0_
I believe this is the correct hose 3/4 to 1 inch. If the bypass is plugged the thermostat will not see hot coolant. I never tried it but when you fill the system pull the heater hose off of the intake water outlet and put a funnel in the hose and add coolant until the block is full then quickly put it back on the housing.
 

ShadowWolf

New Member
Joined
Jan 21, 2014
Messages
18
Reaction score
0
Points
0
Vehicle Year
1984
Make / Model
Ford
Engine Size
2.8L
Transmission
Automatic
About to head back down to work on it and I will check that out. I will keep an eye out for that upper housing kimcrwbr1 as I really hate the setup thats on there.
 

ShadowWolf

New Member
Joined
Jan 21, 2014
Messages
18
Reaction score
0
Points
0
Vehicle Year
1984
Make / Model
Ford
Engine Size
2.8L
Transmission
Automatic
the bypass hose is definitely not blocked, I disconnected the hose from the upper nipple and water freely pours out of both the hose and the nipple. This just gets better and better lol. It would seems that everything works as it should, but that darn stat just wont open... Could it be a REALLY pesky air bubble? I have tried filling the system many times over, following the directions on the rad support. And I never had this much trouble before the truck overheated and I replaced the head gaskets.
 

ShadowWolf

New Member
Joined
Jan 21, 2014
Messages
18
Reaction score
0
Points
0
Vehicle Year
1984
Make / Model
Ford
Engine Size
2.8L
Transmission
Automatic
Put the thermostat back in after testing it again and I still have the same issue, The temp gauge is all the way up, cab heat is so hot that you cant hold your hand on the vent and yet the lower hose is only luke warm at best. With the cap off the rad there is visibly no flow save for a TINY trickle. I don not know what else to do here, I'm at the end of what I have been taught by people.
 

kimcrwbr1

Well-Known Member
Joined
Dec 6, 2009
Messages
6,044
Reaction score
43
Points
48
Location
maplevalley WA
Vehicle Year
1983
Make / Model
ford
Engine Size
2.8l
Transmission
Automatic
Sounds likr you need to flush the radiator. It is best to pull it out do you have a hose outside that works good drain and backflush the radiator using high pressure water I like to use a long hose and kink the end to let it build up pressure and quickly release it with a tight seal on the lower fitting keep the radiator cap on. Then drain and fill it with half water bleach and let sit overnight. Oven cleaner actually works best anyway flush it good both ways with high pressure water a few times. You can test the radiator by disconnecting both hoses and with the cap on seal the upper fitting with the hose and see if water runs free through it the high pressure from the hose should clear out a good part of the blockage if it is. The problem I finally figured out is the block was full of rust I bought a new radiator and water pump. Withe the pump and upper hose housing off the manifold I took high pressure water to the inside of the block and it stirred up all the rust that settles in the low spots believe me there was alot of crap in there. Just blast it good with high pressure water until only clear water comes out. put the new water pump and radiator in and for two years the coolant is still green as it was when I filled it up.I did find putting a flush adaptor tee in the heater hose that gose to the intake manifold and top it off through the heater core gets rid of all the air that gets locked in the upper engine and heater core. Anyway been where you are you just need the right combo of events and you will figure it out.
 

ShadowWolf

New Member
Joined
Jan 21, 2014
Messages
18
Reaction score
0
Points
0
Vehicle Year
1984
Make / Model
Ford
Engine Size
2.8L
Transmission
Automatic
Funny you should mention rust... The coolant I took out when changing the head gaskets was brown.

EDIT: I will still try flushing the rad, but there was really good flow without the stat. Would you still say the rad needs flushing?
 
Last edited:

kimcrwbr1

Well-Known Member
Joined
Dec 6, 2009
Messages
6,044
Reaction score
43
Points
48
Location
maplevalley WA
Vehicle Year
1983
Make / Model
ford
Engine Size
2.8l
Transmission
Automatic
By the way did you stick something in the upper nipple for the bypass hose the hole should be at least 5/8 inch for good water flow to the thermostat.
 

kimcrwbr1

Well-Known Member
Joined
Dec 6, 2009
Messages
6,044
Reaction score
43
Points
48
Location
maplevalley WA
Vehicle Year
1983
Make / Model
ford
Engine Size
2.8l
Transmission
Automatic
It wouldnt hurt I would still try reaming out the upper bypass nipple see it it is nice a nd clear.
 

ShadowWolf

New Member
Joined
Jan 21, 2014
Messages
18
Reaction score
0
Points
0
Vehicle Year
1984
Make / Model
Ford
Engine Size
2.8L
Transmission
Automatic
I was able to stick a socket extension in there, but I do not have a 5/8ths ream at this place. I'll give it a more thurough look when I pull rad out. I have another pump gasket, maybe I should pull that too and get in there with a hose the best I can. Or what If I ran the engine with a hose at the lower intake and let the top drain out until I have clear water?
 

wildbill23c

Well-Known Member
U.S. Military - Veteran
TRS Banner 2012-2015
TRS 20th Anniversary
Joined
Aug 22, 2012
Messages
3,799
Reaction score
463
Points
83
Location
Southwestern Idaho
Vehicle Year
1988
Make / Model
Ford Bronco II
Engine Type
2.9 V6
Transmission
Automatic
2WD / 4WD
4WD
Total Lift
0
Total Drop
0
Tire Size
235/75-R15
My credo
19K, 19D, 92Y, 91F
Bad thermostat? I went through 7 of them before I finally got one that worked from NAPA several years ago when I had the exact same issue with overheating in my 84 Ranger.
 

ShadowWolf

New Member
Joined
Jan 21, 2014
Messages
18
Reaction score
0
Points
0
Vehicle Year
1984
Make / Model
Ford
Engine Size
2.8L
Transmission
Automatic
I suppose it's possible, but I did check it by heating a pot of water to just below boiling and putting the stat into it. Opened up just like it should. I'm gona flush out the rad and block and see if that helps. If not then I'll try another stat.
 

kimcrwbr1

Well-Known Member
Joined
Dec 6, 2009
Messages
6,044
Reaction score
43
Points
48
Location
maplevalley WA
Vehicle Year
1983
Make / Model
ford
Engine Size
2.8l
Transmission
Automatic
I tried a bunch of different things pulling the water pump and flushing the block with hose was the only thing that got rid of the rust. If the engine was getting that hot you may consider a new pump if it works. My experience is the seal will start dripping coolant as soon as you get it sorted out you know murphys law. It will still run a little hot until you find a thermostat housing for the upper hose thats the nature of the beast.
 

Sponsored Ad


Sponsored Ad

Top