Cooling Question - First Gen.

[ford4wd08]

There are different thermostats for 2.8s. The brass one on the right is the part for engines with the lower thermostat.

I have a lower stat on my B2 and had no idea it used a different style thermostat.

I believe I replaced the original and don't remember it looking like the one you have pictured.

I currently have a high flow one from rock auto in my that is 160 degrees, it takes a while to warm up, but it does not get close to overheating like it did running the AC in the summer.

 

[ford4wd08]

You’re right. I just made this up to post on the internet for funsies.

Here’s a picture of the updated thermostat housing and how the setup looks installed.

Looks like this relocates the temp sending unit too compared to the other style? Is it a simple swap to this upper unit, would love to have my thermostat on top of engine, it is such a pain on the lower one to have to change it or drain it.

 

[AndyB.]

The intake manifold is different. The bypass connects to the upper housing instead of the intake. You could probably cap that, clamp it, and get the two housings (I can get you part numbers). You’d also need a thermostat, gasket, and bypass hose.

 

[ford4wd08]

The intake manifold is different. The bypass connects to the upper housing instead of the intake. You could probably cap that, clamp it, and get the two housings (I can get you part numbers). You’d also need a thermostat, gasket, and bypass hose.

Might be easier to just stick with what I have. The 160 stat is working well, I just put it in this last fall. It does get to operating temp, but just a little slower. That is in the winter, in the summer I'm sure it will heat up no problem.

Sadly I've been driving my new to me F250 since I bought it in November, I'll have to get the B2 out of hibernation soon.

 

[Bronco648]

Just an update: it hasn't been a typical Chicago winter with temps in the upper 30s to upper 40s over the past month or so. That said, nothing has changed on the cooling 'issue' either. Once the fan comes on, it stays on but the temp gauge (again, caveats apply) stays in the upper range of the needle sweep (nearest the "o" in "norm"). When the upper radiator hose is a little too hot to grasp, the lower radiator hose is warmer than the ambient temp but cool in contrast to the upper hose.

 

[RonD]

Radiators cool 15degF with no fan/air flow
20-25degF with air flow

So lower hose should be only 15-25degF cooler than upper hose if there is good flow thru radiator, after warm up

Reads like flow thru radiator after warm up is poor
So either radiator itself is restricted or upper or lower hose is restricted(thermostat) or water pump is weak

Ford uses 205degF as center for temp gauges, "N O R M A L" letters don't help, as their position changed by year, lol
So use 1/4, 1/2, 3/4 and/or 1/3, 2/3 to indicate needle position

Engines should run at 180-190degF, so just below center after warm up, regardless of outside temps
210-215degF under load, just above 1/2, i.e. up a long grade or pulling a trailer, thats OK, not overheating
3/4 on gauge is when its starting to overheat

 

[Bronco648]

Radiators cool 15degF with no fan/air flow
20-25degF with air flow

So lower hose should be only 15-25degF cooler than upper hose if there is good flow thru radiator, after warm up

Reads like flow thru radiator after warm up is poor
So either radiator itself is restricted or upper or low hose is restricted(thermostat) or water pump is weak

*Caveats Apply*
Radiator, upper hose, lower hose, t-stat and water pump are all new.

It's possible, however, that I have the wrong t-stat or installed it incorrectly. I have the early 2.8 with the 'low' t-stat. @AndyB. is sending an NOS 'low' t-stat to me so I'll try that (as that assembly is showing signs of leaking).

Ford uses 205degF as center for temp gauges, "N O R M A L" letters don't help, as their position changed by year, lol
So use 1/4, 1/2, 3/4 and/or 1/3, 2/3 to indicate needle position

Engines should run at 180-190degF, so just below center after warm up, regardless of outside temps
210-215degF under load, just above 1/2, i.e. up a long grade or pulling a trailer, thats OK, not overheating
3/4 on gauge is when its starting to overheat

I'd say the gauge reads 2/3 to 3/4 (the gauge face has "NORM"). It seems to be pretty obvious when the t-stat opens (I think) as the gauge will top out @ N (3/4) and then drop to O (2/3) and seems to stay at O. My t-stat is 192*.

It certainly doesn't hurt that my commute is short (5 miles) and the weather is cold (20* to 50*).

 

[Angie]

I'd say the gauge reads 2/3 to 3/4 (the gauge face has "NORM"). It seems to be pretty obvious when the t-stat opens (I think) as the gauge will top out @ N (3/4) and then drop to O (2/3) and seems to stay at O. My t-stat is 192*.

why not place in a mechanical gauge then you will know the exact temp, give or take a degree or 2?

 

[RonD]

Lower hose t-stat should be 160-180degF, that keeps upper engine/heads at 180-200degF which is best operating temp, i.e. lower engine/hose is 20deg cooler than upper if everything is working like it should

 

[Bronco648]

why not place in a mechanical gauge then you will know the exact temp, give or take a degree or 2?

TBH, I'm sick & tired of futzing around with this thing (which is why it's for sale). Everything seems to fail or not work. I have a brand new master cylinder that's leaking from the rear seal. I have a brand new fuel pump that's leaking from the diaphragm. I had a mechanical oil pressure gauge that refused to seal, at the block extension, so I reverted to the pressure sending unit. The racer in me would prefer mechanical gauges but I'm not adding more to an already 'too long' punch list.

 

[Bronco648]

Has anyone installed a manual choke on a 2150? Here's another item that refuses to work properly (electric choke t-stat). But, there doesn't seem to be a convenient place for the outer sheath support bracket, near the carb. A picture would be most helpful.

 

[4x4prepper]

> The racer in me would prefer mechanical gauges

I would avoid a mechanical oil gauge, I have seen and heard of too many blown engines when the tube breaks, which is especially painful on a diesel engine. When I buy a used vehicle and it has one, it gets replaced or plugged. Of course on the 2.8L, with the big honking sender, it has to be in the worse place to replace the fuel pump.

> Everything seems to fail or not work

I feel your pain, quality aftermarket parts are getting hard to find and Dorman now is a crap shoot on if the part will last a month. Made in Taiwan use to mean at least passable.

 

[Bronco648]

Of course on the 2.8L, with the big honking sender, it has to be in the worse place to replace the fuel pump.

I've gone back to the o.e. sending unit but have it oriented so that it points downward. It still doesn't make getting to that lower fuel pump bolt any easier.

I feel your pain, quality aftermarket parts are getting hard to find and Dorman now is a crap shoot on if the part will last a month. Made in Taiwan use to mean at least passable.

I was wondering if anyone else was experiencing this too. At least I'm not in my own private hell with the after-market. Still....

 

[Bronco648]

OK, back to cooling issues. I honestly have no idea what the issue was. But, I did get an o.e. t-stat from @AndyB. (thanks again!) and installed it. Before installing, I verified that it opened at 188* F. I followed the special 2.8 coolant filling procedure (and did the first time, too). This time I took the truck outside and let it idle waiting for the t-stat to open by observing the coolant level through the radiator opening (rad. cap removed). It eventually did open as the coolant level dropped dramatically. I witnessed the electric fan cycle on/off twice. So, something changed but have no idea what.

I also checked the t-stat that I removed (Motorad 192* from Rock Auto). It also opened when it was supposed to. I see no issue with either t-stat. The one thing I did notice was that O-ring, that goes between the flat gasket and the t-stat (I believe it's there to hold the t-stat in the water pump) was not seated properly. See below. It looked like it had collapsed a little (kind of resembled a Pac-Man shape). I suppose it's possible that it was restricting water flow from the radiator into the water pump/engine?

Anyone want/need a new t-stat? Motorad part: MOT 234-192. LMK.

 

[AndyB.]

That o ring seal is a problematic design. 20 years ago I found an aftermarket one that was larger in diameter and thickness, it would stay in place on its own.

Factory parts in this picture, no idea how to keep that ring in place while tightening it down.