Okay, will take another look, at belts, bleeding, and the other things you mentioned.

 

He put in 1.5 gallons of coolant, he did bleed the system. Got the diagram for the belt and said that is one hell of a belt route. He will check that tomorrow. Thank you so much Buzz.

 

OK - and have him check the fan clutch as well.

 

Getting the air out of the system can be a little tricky. We all went through this at one time.
Your husband is right. The thermostat will not open to circle the water through the system on the idle. Here is why. FAN SPINS ALL THE TIME!!!!! Thus keeping the temperature in the rad just under the temperature required that is needed to get the thermostat to open.
Looking at the coolant container (with the cap open during the "air bleed") and the engine running, once the truck gets hot it will want to overheat and you can actually see the antifreeze level starting to raise. Open the throttle (rev the engine) and you will see the coolant level in the container go down. However....this causes the temperature in the radiator to drop, because the fan speed had increased and cooled the antifreeze once again. And this is a vicious cycle that will keep going forever!!!!!
You need to block the radiator from the fan with a piece of plywood (something stiff to the fan doesn't suck it in) and go through the "air bleeding cycle" again. You need to take off the top plastic cover that's above the radiator so you can slide this piece of plywood between the fan and the rad.
So....
1. Block the radiator from the fan with a piece of plywood (THIS IS THE MOST IMPORTANT PART)
2. Run the engine until it gets warm and keep the cap off the coolant reservoir so the air can bleed out.
3. If the coolant level in the container starts to raise...rev the engine just a little bit and you will see the coolant level go down. KEEP YOUR EYES ON THE COOLANT RESERVOIR AT ALL TIMES. TRUCK CAN OVERHEAT as your husband already found out!!!
4. Very soon after this (2-5 minutes) if you touch your lower hose under the thermostat it will go hot from being cold. This meens that the thermostat is finally open!!!!
5. Remove the piece of plywood you used to block the radiator from the fan so the truck cooling can now work normally.
6.Let the truck run for another 10 minutes or so, add coolant in the reservoir if needed and put the cap back on the reservoir.
7. Shut the truck off and have a great day. Ohhhhh you might want to check the level of the coolant next day as it may be lower by a bit than from day before.

Tell your husband to be careful when he places this piece of plywood between the rad and the fan as this is very dangerous. Lots of moving parts that can do damage to your hands!!!!!

This works for me every time I do coolant flush or I need to bleed the system because I had to remove hoses or what not. Thermostat opens very quickly and easily.

Hope this helps.

Cheers.

 

And the size of the air "bubble" is so large that it fills the top hose and part of the thermostat housing. The stat does not perform the same in steamy air as it does in hot water. The cooling system holds 13 quarts, or 3.25 gallons. Much of that would have been out when thermostat was changed. Should be able to open bleeder valve and pour in more coolant to coolant bottle until it comes out the bleeder, even squeeze the hoses some. Once you have all you can in there, then start the process boris_gti describes on previous post. A combination of bleeder valve and coolant jug cap should improve things. But right now, don't drive truck, you did not get enough coolant back in, no heat indicates that, plus overheat.

 

Wow, just printed all of this out, thanks Buzz

 

Here's more - print and have him pay attention to step 6 on the second page. The bleed screw lets you fill with coolant while most of the air gets pushed out, making room for the full quantity of coolant. Then the Boris_gti method gets rid of the last of the air. And noise under the dash will be gone.

Note - if bleed screw is damaged, can get relacement at BMW dealer I am told.

 

I have never had a problem with air pockets after changing coolant, which I have done at least 3 times in the past 4 years due to every 2 year change, then replacement of all hoses.

My method: with engine cold, remove bleed screw, remove battery cover, un-clip coolant reservoir, and place over hydraulic jack/ battery box (the rear tab of the reservoir seems to keep the reservoir elevated without input when put over the jack tray). Fill coolant reservoir until coolant comes out of the bleed screw opening in a steady stream, then continue filling coolant (maybe 1/8 gallon for good measure to ensure steady stream). Refit coolant bleed screw while coolant is pouring out, replace reservoir to original location. Start engine, turn heater to max Hot level, add coolant to reservoir as level drops. Recheck coolant level the next morning, and top off as necessary.

 

re: remove bleed screw

This step may have been skipped by OP, which kept enough air inside to prevent enough coolant to be installed. Water pump did not have enough to circulate, therefore heat was "cold". Only got in 6 quarts after a thermostat change.

re: turn heater to max Hot level

Not needed as much in a D2, where coolant always runs thru heater core, temp is controlled by blend flaps. Certainly needed on D1's.

Part about adding coolant until it comes out bleed hole and keeps coming is important point. It is better to be messy and have full system that spotless and keep the dash mounted gurgle gremlin.

 

re: turn heater to max Hot level:
I thought I had seen this mentioned in RAVE, but upon looking again, it isn't. Perhaps I saw it in some kind of writeup on this site. I think I have always done this, one of those things you do, because you thought you read it somewhere, and don't even really think it through. I suppose, though, that by having the max air flow across the heater core, the coolant will take longer to reach normal operating temperature, giving the operator more time to refit bleeder screw, reinstall reservoir in mounting clips, verify coolant level, all the while running back and forth to the passenger compartment to make sure the temp gauge is where it should be.