Geez, I hope this doesn't turn into a saga. I am going to do the stuff with the heater today. If that doesn't do it, I guess I will go buy another tstat and hope for the best. After that, I'm going to the mechanic...

One more thing that helps...
 

It also helps to park the car on a slope with the radiator pointing up. This helps to get any air out of the heater core.

I would take the top hose off the radiator, pull it up as far as it will go without kinking and fill it with water until water comes up to the level of the hose. When I use this method of filling the block, I never have air issues..

i betcha it is air

did you note the orientation of the arrow on the t-stat when you installed it?

If not, check that first.

Drain the radiator into a clean bucket so you can recycle the coolant, then open the t-stat housing. You will still lose some coolant.

There aren't any slopes here in Florida...

Raise up the front end or drive onto some ramps.

Well, I did the heater thing and still with the same issue. When it cools down I am going to take out the thermostat again. I am not understanding why I would have to drain the radiator. I know that I am going to lose some fluid. I guess it's not hard to refill. Just curious. Just wish it wasn't so hot out when I am trying to accomplish this. I really should get a/c in the garage!

I have drained the coolant out again. Should I just do whole flush since I am already here? Can someone instruct a layperson how to do it? Or should I not mess with it? The coolant that's draining out is a bit rusty looking, considering I did install a new radiator and hoses. Or is that the way it typically looks for a 30 year old car? If I want to do a complete flush, exactly how would I accomplish that? Thanks, Lance I have a 300D 1983.

Basically I am going to check the thermostat out and make sure the arrow is pointing in the right direction. :eek:

okay. have the tstat out. is the disk part supposed to go towards the engine or the radiator? The "arrow" was pointed directly to the east and not north. Maybe I put it in backwards? Thanks, Lance:confused:

It would help it I posted a pic. Disk part is the the foreground in this pic

A full flush is not a bad idea, but it is also a bit involved (not hard to do, just involved).

It requires draining the radiator and block, flushing with fresh tap water, draining again, running with a degreaser, draining again, flushing with tap water, draining again, running with citric acid, draining again, flushing, running and draining a bunch of times with tap water, filling and running with distilled water, draining again, and finally adding straight coolant and topping off with distilled water. Each fill requires running the car to operating temp for at least 5 minutes (according to the FSM). Its a full weekend job and a pain in the butt.

In an ideal world you should do a full de-grease, de-scale, coolant flush every few years. But, since your system ran at the proper operating temp before the work (new radiator, new t-stat, new filler cap), a flush won't solve your current problem (high running temps after the work).

The rust comes from the engine passages (iron block), not the radiator (aluminum).

Right now, I would focus your efforts on getting the car running at the proper temp again (and worry about coolant flushes and descaling later). Like I said before, if the car was running at the proper temps before the work (~90 C) and is running high after the work (>100 C), then the problem is directly related to the work (either air bubbles or the t-stat). My money is on the t-stat. Make sure that it is installed properly.

All this brings up the question of what exactly happen to the radiator in the first place. You said "it puked". What does that mean? I assumed that the neck to the overflow line to the expansion tank broke off. Am I right? Was teh car running at proper temps, when you refilled it with water (after the puking)?

Douglas, first, i notice steam coming out of the hood crack and looked at the gauge, 120 mark, immediately shut off the a/c and pulled off. The neck broke, I was able to get the hose back on, fill with water and drive home. The temp was good going home. And then I changed it for a new radiator, hoses, t-stat, etc. BTW, I have it apart now and the tstat arrow was pointed east. Also I don't know if I installed it the right direction. Should the side with the disk on it be towards the cabin or towards the radiator? Yikes! Guess you can tell I'm not a mechanic...

Here's a drawing:

http://homepage.mac.com/cbaronxxx/PhotoAlbum4.html

The "foot plate" (the part you can't see in the picture) goes into the t-stat housing toward the back of the car (it actually block off the access hole when the t-stat is cold, preventing coolant from running through the radiator). The tab on the o-ring with the hole in it goes at about 10:30 as you look at the t-stat housing from the front of the car (the only way it will fit). And the arrow on the t-stat housing points to 12:00.

For the sake of argument, once you have the t-stat housing closed up remove the upper radiator hose from the radiator and slowly refill the drained coolant (filter out any rust chunks) through the upper hose. This will fill the block.

When its full, put the hose back on the radiator (quickly) then fill the rest of the way through the expansion tank. This will fill the radiator.

Leave the filler cap off, press the defrost button and run the engine at intermittent speeds up to operating temp (its best to drive it a very short distance). Add coolant to the proper level as needed (below 90 C). This is the FSM prescribed method for refilling the coolant system, and should allow any air bubbles to work their way out of the system.

I take it back. It looks like the foot plate is in the front of the picture.

Edit: definitely. You are looking at the back of the t-stat in the picture.