top hose hot bottom hose cool ?

[mattsmopars]

On my 65 coronet wagon, I just rebuilt the 383 and got it all running. I have been doing some tuning on it, and drove it some , but on sunday i drove it around a few miles and it started to get warm so I brought it home. Since then I have ran it in the garage and noticed tonight that the top of the radiator was hot , and the bottom was cool the same with the hoses. Top was hot bottom was cool. The engine has a new water pump, 180 degree t -stat,hoses ,belts. I also had the radiator rodded out and cleaned while it was apart, and have used all new coolant. Also installed a factory fan shround. It seems as if I rev the car it it heads up toward 200 rather quick. So what do you think? Does the radiator need to be recored?
Matt

 

[bigmanjbmopar]

Well, new motor = runs hot from the start. about that stat if it's hot on top and cold on the bottom I could only think the stat isn't opening the stat is new? even if it is try a new one or like others do drill a small hole in it the racers can tell you exactly where.

Open cap on the radiator and while the engine is running see if you can see any movement from the antifreeze it should be swirling around if the stat opens at temp.

Are you sure that there is no clogging in the water ports?

 

[Revhendo]

What are you using for a fan? What type of water pump? If you rev the motor, does the lower hose collapse?

 

[moparsteve636]

Possible air lock!How much coolant did you put in?

 

[mattsmopars]

It has the factory fixed blade fan, original replacement A/C water pump with the factory cast iron water pump housing. Top and bottom hoses have springs in them to keep them from collapsing.
If it is an air lock, witch I thought of since I drained it down some a couple days ago to add a mechanical temp sensor in the water pump hosuing. How or what do i need to do to get it out? I was able to put all of the coolant back in the I drained out. Almost acts like the t-stat is stuck closed, but it is a new robertshaw type, so surely it would not be sticking. I guess stranger things have happened.
Thanks for the help, I apprecaite it.
Matt

 

[moparmarks]

Silly question but you did get the stat back in right side up? Otherwise sounds like the radiator may have a flow problem.

 

[mattsmopars]

Silly question but you did get the stat back in right side up? Otherwise sounds like the radiator may have a flow problem.

Yeah, I have not had it back out since I put it together , but yes to answer your question it is in correct. BTW no such thing as a silly question, sometimes things get over looked.
Matt

 

[moparmarks]

Figured you did. Sounds like you have everything covered on this. I'd pull that rad for a flow test.

 

[Revhendo]

Generally speaking, if the T stat stuck, the top hose wouldn't get hot, either. (If it's stuck, it won't allow coolant to flow).

 

[super-bee_ski]

Another "silly" question:
Is 200 F really "Hot" ? Or, is it climbing way past 240 F.
Also; If I remeber correctly;
1. If it overheats at idle it means: a. Fan b. thermostat or c. coolant flow issues and or air pocket. (if I remember correctly)
2. If it overheats at speed it means: WATERPUMP (I think)
Does this sound "sound" ?
Some radiator shops put too much BLACK paint on the radiator, it gets too thick and does not promote "good air flow" (Eastwood has a truly thin paint)

I know this: If the water pump is spinning too fast, it can cause cavitation, air pockets and bubbling. This occurs when we change pulley ratios OR mix pulleys not compatible w/ other pulleys.
* Also, a new thermostat can be faulty. I have "ops checked" them in a clear glass with boiling water to visually see it open.
One more thing: "It's usually the simplest item"
Damn overheating issues, PHDs "study" this stuff and "WE" still have issues!
Good Luck and keep us posted!
"Super-bee_ski"

 

[Cranky]

How was the block cleaned when it was rebuilt? Some still use the old caustic vat (very dirty way to do it) and the caustic doesn't knock out rust scale in the water jackets. This could present a flow problem once the engine is fired up and the rust scale starts flaking off and clogging the radiator. I used to have an inline screen that was placed in the top hose and on one new engine, this screen became clogged 3 times but it kept the radiator safe. Had to really watch the gauge closely because the temp would rise quickly once the screen got stopped up. Also, I like to clean the water jackets myself before I send the block out for cleaning and leave the core plugs out before it goes into the washer. Some places don't give a damn and throw it in the wash vat before removing the plugs. Most here don't/can't use the old caustic vats anymore because of the EPA but there are still some in use. Another tip is to check the stat on the stove using a thermometer and paying attention when it starts opening to make sure it works. I've had a couple over the years that didn't work....

 

[mattsmopars]

Thanks for all of the replies, and some very good advice i might add. I don't think that 200 is super hot , but it is headed that way so I shut it down to keep that from happening. As for how the block was cleaned , I am not for sure as I bought the short block assembled without the cam and lifters. So I guess that is a possiblity. I guess it back to work, I will keep you posted.Thanks again to you all! Matt

 

[mattsmopars]

I am thinking that the radiator is the problem and not circulating. They heater hoses are getting hot so the t-stat would have to be opening correct?

Matt

 

[bigmanjbmopar]

I am thinking that the radiator is the problem and not circulating. They heater hoses are getting hot so the t-stat would have to be opening correct?

Matt

no there could be water in the lines for the heater core and block it's just not getting past the stat or circulating in the rad.

 

[Crizila]

Pull the stat and run it that way. If you have the same situation, most likely a clogged rad. If you were at 200, it was already off the stat and would most likely keep climbing. If the bottom hose is cool to the touch, you have a clogged rad core.

 

[Revhendo]

no there could be water in the lines for the heater core and block it's just not getting past the stat or circulating in the rad.

If it wasn't getting past the stat, the top hose would be cold. Sounds like the problem is most likely in the radiator. My reasoning would be because as the engine speed increases, so does the heat. The water pump may not be able to pull the coolant through.