Heat is Warm but not Hot

[MakinJeepsWeep!]

Motor craft is a good call. Like i said on my newer stuff it actually threw a code for the engine not getting to the right temp in the right time even though they were the same temp they wanted the motorcraft part. This happend on 2 4.0s one in a 10 anniversary stang and a 06 premier merc

 

[MakinJeepsWeep!]

Be sure to give us a update when you get the new parts on.

 

[massacre]

Will do!
still waiting on parts to arrive

 

[410Fortune]

yes please do
Have a 98 ex in the family with 260K on it now....(low mile 5.0 drivetrain) well it lost a waterpump a couple of weeks ago and to limp it home they added a ton of stop leak to the cooling system...now the heat is not hot.
I replaced the WP, thermostat, some hoses, etc...... blew air backwards through the heater core.
I suspect the HCV, heater core or blend door.....so watching this thread

 

[CDW6212R]

yes please do
Have a 98 ex in the family with 260K on it now....(low mile 5.0 drivetrain) well it lost a waterpump a couple of weeks ago and to limp it home they added a ton of stop leak to the cooling system...now the heat is not hot.
I replaced the WP, thermostat, some hoses, etc...... blew air backwards through the heater core.
I suspect the HCV, heater core or blend door.....so watching this thread

I hope you figure that out, and have you flushed it yet? What stop leak did they use, do you know?

I have my white truck running with a bad timing cover gasket, and about 1.8 bottles of Liquid Copper in it. The first lasted about ten days, and the next one has no noticeable leak yet. I flushed it before trying this product, and it may or may not last the Winter. I wonder how much creates trouble in the passages, heater core too of course.

 

[410Fortune]

They put in one bottle of K seal and then two treatments of blue devil, it was enough to get them home

I back flushed the heater core with AIR, since it is middle of winter I did not want to run a bunch of water on the driveway
It would be best to backflush it with hot water
The air pressure took a minute to blow out some crap from the core then it ran smoothly, however I believe there is a larger blockage in there.
Today I plan to bypass the HCV, then remove the blend door actuator and have a look at the blend door axle shaft and watch the actuator move back and forth. I have fixed more then one gen II explorer by messing with the blend door axle

 

[CDW6212R]

Thanks, mine has the bad blend door now, so I have it at 90* to keep it warming, it's hot so far all the time. I'll get into the blend door swap soon. I have heard of Blue Devil but never read anything about it. My coolant is basically clear with minimal particles seen, so the material has to be settled throughout the system. I don't want to add more, or have to flush it every time it leaks again. My fingers are crossed.


I thermostat of OEM 195* level will make high heat, the 180 is still very warm for most people. If the air isn't blowing forcefully, changing the blower motor is a good idea. Those are all old, and they aren't that bad to change. Just be careful with the blower fan blade, R&Ring it from the old shaft(save the clip if the new one doesn't have one).

 

[massacre]

yes please do
Have a 98 ex in the family with 260K on it now....(low mile 5.0 drivetrain) well it lost a waterpump a couple of weeks ago and to limp it home they added a ton of stop leak to the cooling system...now the heat is not hot.
I replaced the WP, thermostat, some hoses, etc...... blew air backwards through the heater core.
I suspect the HCV, heater core or blend door.....so watching this thread

Just to be clear, I ordered a blower motor, resistor, and thermostat.
I am waiting on ordering the heater core and HCV, in case the thermostat fixes it.
If the thermostat doesn’t fix it, then I will replace the HCV and heater core.

 

[CDW6212R]

I'm sorry I moved the thread off of your topic for a short while. Those three items are all important and not a waste of money to change.

 

[massacre]

I'm sorry I moved the thread off of your topic for a short while. Those three items are all important and not a waste of money to change.

No apology necessary, everything you said was on topic.
I was a fleet mechanic for years with a huge fleet of Econolines, so have changed a ton of blower motors/squirrel cages. You are totally right about the clip, usually a FoMoCo blower motor comes with a new clip, if not I think I have an extra one here somewhere.
Good looking out

 

[CDW6212R]

Thanks. I saved the clip from the last one I replaced, and kept the new one as a spare. It took a few minutes to wrangle the thing apart, getting the right grip on it to hold it still was key.

Be happy to be working on the 1st gen truck, those are not bad at all versus the 2nd gen, and who knows about the latest. I never had any trouble with my 91 or 93, and it's good to read that the heater core is easy to R&R.

 

[massacre]

Parts came today
Gonnna install them tomorrow

 

[MakinJeepsWeep!]

410 If they had the heat on i would agree its clogged, i cant see the heater core having the same amount of flow per area as the rest of the system and it is always possible that the valve is stuck as well or atleast enough that the vacuum can not over power it.

 

[MakinJeepsWeep!]

massacre not that i hope you have a failed part but i hope that the thermostat fixes it because i have a strong feeling thats the issue.

 

[massacre]

massacre not that i hope you have a failed part but i hope that the thermostat fixes it because i have a strong feeling thats the issue.

Thanks!
I agree. I want to replace the blower motor since I was getting some electrical burning smells and that fan had to be working hard with such bad blockage lol. May replace the switch too for good measure, we‘ll see.
New MoCraft blower motor came with new squirrel cage installed, new gasket/seal and new rubber hose that goes from the heater box to motor. So all the bells and whistles which was nice.
New thermostat also came with a new gasket. I ordered a gasket just in case so now I guess I have an extra one lol.

I have no problem replacing the HCV and heater core, that stuff is above the blower motor and resistor so can always do it later.

 

[massacre]

Just pulled the “stock” blower motor. Sticker on bottom said VDO made in China.
New OEM says FoMoCo made in Canada.
stock resistor is motor craft though. Was able to get the connectors off without breaking, the resistor is the worst lmao
small amount of green corrosion but not too bad at all. I’ll clean that up and put some dielectric grease there.

 

[massacre]

Blower motor and resistor went in easily and work great.
Forgot how much of a pain it is to replace the thermostat housing with everything in place.
Old thermostat was stuck open.

New one went in pretty easily, so far no leaks.
Temp gauge is working again, heat is blowing hot again.

While I was there I noticed drivers valve cover leaking oil, tightened up the bolts, they weren’t that tight. So hopefully I solved a few problems today.

 

[CDW6212R]

Bingo. It had overheated, that is a Motor Rad thermostat. I have that in my 99 SOHC, I tripped it twice in six months. The thermostat can be fixed, it was tricky to crush the spring and retract the tangs to let the spring go back where it belonged. I drove in Winter with one of those, on highway it wouldn't get much above 105*(the coolant).

 

[massacre]

I suspect I will see a slight increase in gas mileage now.
I don’t remember the truck overheating, or even running hot since replacing that thermostat?
I’m hoping I’ll get better results with this Motorcraft unit.

 

[CDW6212R]

I don't know what the trigger point is for those, but I suspect it's around 250* or so. I hit 270 as seen on a Scangauge device, and 282 the 2nd time. Mine were unexpected, my electric fan relay tripped when I washed the engine, and the next day at work I noticed a very high idle. I caught it, I had the Scangauge on all of the time. Shut it down, fixed the relay, and added about two liters of water. Later after R&Ring the thermostat, I had forgotten to add anti-freeze to get proper ratio, in Winter the radiator froze. I got to work and after a couple of hours had to add less than about 15oz. No harm luckily, but it was my fault for not checking the anti-freeze, and that morning we hit about 4*, it was 9* at my house when I left. I usually have my ratio set for about 0-10*, which will work if you keep it at that. But I wasn't there, cleaning the engine was a mistake that Fall, and the "marine" relay wasn't water resistant obviously.