Re-Radiator Strategies : '89 Automatic 2.9L 4x4 w A/C

[eightynine4x4]

1/2 on Ford gauge is actually 205deg, typo

Start cold engine and feel upper rad hose and heater hose, both will be cold of course
Check both again after 2 or 3 minutes of idling
Heater hose should be warming up
Upper rad hose should NOT be warming up

Heater hoses are on the engine side of cooling system so always have circulation

Upper(and lower) rad hose are on the thermostat side of cooling system so have no flow until thermostat opens
So if upper rad hose is warming up same as heater hose then thermostat is open when it should be closed

Great thank you.
Another test, I believe, would be to pump some water into a heater hose and leave the lower radiator tube disconnected from radiator. If water comes down and out, Tstat is open.
I will give this a shot today after truck is cooled completely, and I think with these two controlled tests confirming the same thing, I can start to formulate a plan.

 

[gaz]

89,

No question what I would do, I would remove the thermostat housing and install a new t stat.

Once those other 2 bolts are out, you may be able to get a set of vice grips on the broken bolt but only after as many days soaking in penetration fluid as needed.

If needed, worst case scenario, remove the upper and lower intake manifolds and perform the fastner repair in the bench. These engines will not tolerate cooling system issues and that housing will eventually leak.

 

[eightynine4x4]

Did the water flow through test and the warmup hose test.
Water does flow through from heater hose down and out the lower radiator hose when that’s opened. It doesn’t come out as fast as it goes in though. It’s more of a heavy trickle. I think the engine was filling up but some was getting through Tstat.

When fully filled and the car is turned on to warm up, the heater hose warms up hotter and much faster than the upper radiator hose. I really had to search for a spot on underside of hose to feel heat and it took like ten minutes for that area to feel warm, as opposed to the nearly immediate warmth of the heater hose.
I guess the conclusion is maybe that the thermostat is stuck partially open, maybe not fully. Not sure if that makes mechanical sense with the way it works but the tests are kinda half what I expected them to be so that’s the only explanation.

89,

No question what I would do, I would remove the thermostat housing and install a new t stat.

Once those other 2 bolts are out, you may be able to get a set of vice grips on the broken bolt but only after as many days soaking in penetration fluid as needed.

If needed, worst case scenario, remove the upper and lower intake manifolds and perform the fastner repair in the bench. These engines will not tolerate cooling system issues and that housing will eventually leak.

Ok gotcha. I haven’t thought of remove the manifolds. Sounds ideal, but as we all know, each endeavor to remove a segment is a can of worms in their own right.
I’ll begin PBblasting the two remaining bolts for a few days straight. I may also try to remove the fan for work clearance. The shrowd is already out but that may not be enough.
Id love to put this project off until the spring but I realized i can’t even set the distributor timing properly until I have a fully warmed up engine. So there it is.

 

[RonD]

It reads like your thermostat is fine
Heater hose warming up faster means good flow
Delayed heating of upper hose mean low flow

And the fact your engine is not overheating means thermostat is not "stuck"

Does the overflow tank get warm coolant after driving for a while?
That can only happen when coolant is above 180degF

 

[eightynine4x4]

It reads like your thermostat is fine
Heater hose warming up faster means good flow
Delayed heating of upper hose mean low flow

And the fact your engine is not overheating means thermostat is not "stuck"

Does the overflow tank get warm coolant after driving for a while?
That can only happen when coolant is above 180degF

I’ll be able to perform this overflow check soon once it’s cooled down again and can add the remaining needed water. I’ve been full flushing again and again, and adding a dose of Prestone radiator flush in the mix each time and running it. Trying to get the cooling pathway reasonably well cleared of brown residue.

 

[eightynine4x4]

Just had a thought..
In general I’m trying to think of all possible impacts on the system that make it cooler.

This truck was kind of a rock crawler before I got it. I’m starting to wonder if maybe the owners made a bunch of mods to keep engine cool during summer climbs, such as losing the AC belt and possibly putting in a thermostat with a much lower temp spec than OEM, so like maybe 160 or something. That would explain why the system seems to function but everything is just too cold since the full scale radiator (auto/AC) is now doing too good of a job. Maybe it’s perfect for high intensity summer engine use, but perhaps not normal operation. They also had gutted the cat.
Im going to look into how to purge air pockets too.
Also still have to set coolant/water level after yesterday’s flush. Trying to complete a few rounds before putting in antifreeze money. Getting close to the edge though, it terms of weather. It got down to 30 last night so I’m playing with ice.
Im also curious about coolant pressure and how to check that, although both that and air pockets seem more like overheating issues, not overcooling.

 

[RobbieD]

Best way I've found to get the air pockets out is to take the heater hoses off the core. Fill the radiator with water/coolant, then stick a funnel in each heater hose, fill each in turn till it won't take any more (the radiator will overflow), and quickly reconnect the hose to the core. Move the heater hoses around a little while doing this, and squeeze and release the upper radiator hose to minimize the air bubble there.

Then drive it a little, and top the radiator (after it cools and isn't pressurized).

Add coolant to the overflow tank, and keep an eye on it. A healthy cooling system will draw the last needed little bit of coolant into the system with driving it, and put the radiator coolant level right at the cap. Add more coolant as needed to put the overflow tank level where it's supposed to be.

Once the system is completely full your overflow tank level should stabilize, as long as you don't have a leak. Make sure that the overflow hose is tight on the radiator neck nipple; a leak here (it's actually a vacuum when cooling down after driving) will prevent the radiator from drawing coolant back from the overflow tank (use a squeeze clamp if needed).

 

[eightynine4x4]

Thank you! Will try this when my cooling is working at real temps.

I took the truck for a 40 minute drive this morning after topping off the cold water until cool Max level in reservoir was reached.

Upon returning, I opened the hood and tried to determine the general temp of the water in reservoir. Results: overflow hose cold, reservoir sides cold, no warmth rising from opened top, and lastly and maybe most importantly, the radiator cap was basically cold. The cap is a brand new Motorcraft.

In considering all the factors Ive learned about here, I can think of no other explanation other than that the thermostat is either totally open or it’s temperate spec is way lower than it should be.

The upper radiator hose was warm and had some pressure. Defintely not hot, just mildly warm using bare hands. Heater hoses were also touchable also, no issue, just nicely warm. Heat in cabin was mildly warm the whole time. Temp gauge only crept up to 1/32 of the normal range. Like a needle width above bottom of normal range.

 

[RobbieD]

For what it's worth, on one of my '94 Explorer Sports I changed the spec'd 190 thermostat for a 180 degree unit. My (stock) gauge went from reading in the TEMP letters before, to staying just above the "low" line and well before the start of the letters afterward.

So, it's entirely possible that a lower rated thermostat was installed in your truck sometime prior, and that it can read a lower temp than normal. Until you test it, you won't know for sure if it's opening, and if so, at what temperature.

You could look at that, and you should test a new thermostat before installing it, when you're ready to deal with the broken t-stat housing bolt. I know how it is, to have to limp something along until it's more convenient to fix it properly.

If the broken bolt doesn't make a leak, I think you'd be OK to run the truck, just pay close attention to the engine temp, and DO NOT let it overheat.

 

[eightynine4x4]

For what it's worth, on one of my '94 Explorer Sports I changed the spec'd 190 thermostat for a 180 degree unit. My (stock) gauge went from reading in the TEMP letters before, to staying just above the "low" line and well before the start of the letters afterward.

So, it's entirely possible that a lower rated thermostat was installed in your truck sometime prior, and that it can read a lower temp than normal. Until you test it, you won't know for sure if it's opening, and if so, at what temperature.

You could look at that, and you should test a new thermostat before installing it, when you're ready to deal with the broken t-stat housing bolt. I know how it is, to have to limp something along until it's more convenient to fix it properly.

If the broken bolt doesn't make a leak, I think you'd be OK to run the truck, just pay close attention to the engine temp, and DO NOT let it overheat.

Great thanks for the input! Yeah I think I dot have much choice but to replace the Tstat sooner or later.
I guess the only thing that legit concerns me about continuing to run the truck for a while with this low temp is that I’ll never be able to truly bring it up to official/mid operating temp when doing the timing adjust of distributor. It will be at the very low line, of the normal range. Not sure how much this throws off the timing setup.

I don’t have any concerns right now about overheating, but if I did leave this Tstat in place I would keep an eye on temp gauge just in case somehow the Tstat closed back up and got stuck in that position.

 

[eightynine4x4]

Well, some good news and bad news.
I’ll start with the good becuse it’s actually the same news…
For months now I’ve been trying to suss out a mystery fume in the cabin. It’s been subtle but definitely there and irritating the lungs. I had already addressed the exhaust quote thoroughly earlier in the year but have been thinking maybe there was still a small crack somewhere.
So today when the sun went down I was planning to shine an LED lamp in various places underneath to see if I could detect air motion. I was already going to be filling the truck with coolant for the first time since flushing.( I am thinking I should hold off on the thermostat replacement attempt for a while.)
Anyways, I filled the antifreeze in two shifts, and fired it up again to start checking for exhaust anywhere…
Quickly I found that there was a small leak trickling down the right wheel well. I opened up the hood to see if the heater hoses were leaking but they weren’t. Then I opened the passenger door, and much to my surprise, using my light I saw some fumes being pumped into the cab by way of the heater vents. So I turned on the heater, and then there was LOTS of smoke being pumped into the cab. There was also a steady trickle of coolant coming onto the passenger floor board.
Recently, I’ve been flushing with water and a small dose of flush substance. I could tell recently that the fumey smell in cab had worsened since before I started flushing. Probably my flush substance was more intense of a burn than the rusty water that had been in the system before.
Now, with real coolant, it’s just horribly toxic. I’ve been wearing a respirator lately since I could tell something was up. But it was never this bad. I’m glad I had it on when this happened.
So, what exactly causes this? Obviously the heater core is the issue. But in what way? I can understand that if there’s a hole in the heater core that coolant will leak out. I had not noticed if this ever happened before. Maybe it began to worsen when I started the flush process. But why all the smoke? It definitely smells like antifreeze burning. Is the heater core hot enough, despite the heat only being luke warm, to cause the leaking coolant to simmer on contact?
What should be my plan of attack here?
And, how might this relate to my overall cooling situation? Any chance it will heat the engine up more when I fix the heater core leak/burn?

It reads like your …

For what it's worth..

 

[RobbieD]

It was steam, not smoke. Bad heater core, and it's not uncommon for a failing core to take a real dump after flushing the sludge out.

You'll have replace it, which fortunately is easy on an '89.

 

[gaz]

Yes steam not smoke.

Fumes by the way are a by-product of welding; they are very small particulate matter with metal properties, suspended in air/smoke.

Vapors are atomized organic gases suspended in air, 2 very different respiratory contaminates.

 

[eightynine4x4]

Yes steam not smoke.

Fumes by the way are a by-product of welding; they are very small particulate matter with metal properties, suspended in air/smoke.

Vapors are atomized organic gases suspended in air, 2 very different respiratory contaminates.

Which is the anti-freeze ? Fumes or vapor?

 

[RobbieD]

Yes steam not smoke.

Fumes by the way are a by-product of welding; they are very small particulate matter with metal properties, suspended in air/smoke.

Vapors are atomized organic gases suspended in air, 2 very different respiratory contaminates.

And even more importantly, where are farts in all of this?