cooling issue

[bdep73]

hey everyone I have an issue that I can not fix no matter what I do and its driving me crazy so I'm hoping someone can help. I installed a Novi 2000 on my car this summer and when I had everything off of the front of the car I decided to change the water pump to a miloden high volume water pump. I also put in a 180 degree mr gasket high volume thermostat. I also had to change the flex a lite fan I had to a flex a lite twin low profile fan to fit the 10 rib Novi pulley. I already had a 3 core mishimoto aluminum radiator on the car.
The issue I am having is after driving the car for 10 min or so the temp gauge will rapidly change from normal to almost overheating and then back down to normal, and this happen every few minutes.
Now I've gathered from reading stuff of the net that I am having this issue because I have air in the system. the problem is I CAN'T GET THE AIR OUT NO MATTER WHAT I DO. I have jacked the front end up, opened up the intake temp sensor to bleed out the air from there and squeezed the hoses all without success.

The reason I think i have air in the system is I can't get enough coolant into the system. I don't know if i am the only one that has had this problem with a high volume water pump or if its not the pump at all but when I take the cap off the radiator and start the car waiting for it to warm up. once the thermostat opens and the coolant goes down I literally do not have enough time to top off the radiator before the coolant is flying back into the radiator from the engine, it happens that fast and the coolant just keeps coming out of the top of the radiator.

I don't know if this is because of the high volume pump but I end up losing more coolant from it coming back out the top of the radiator then I can get in it, is this caused by the pump or is there something else wrong that I am unaware of.
The mishimotto radiator came with a 19lb radiator cap which i thought was maybe too high so i tried a 16 lb cap but that did not change the temp from rapidly fluctuating. Any help you guys could give me would be greatly appreciated.

 

[f8tlfiveo]

Sounds like air in your system to me. Does the heat go away from time to time while driving? Never used a high volume pump. I don't think it is necessary. I would put a stock pump back on and see what happens.

 

[bdep73]

Sounds like air in your system to me. Does the heat go away from time to time while driving? Never used a high volume pump. I don't think it is necessary. I would put a stock pump back on and see what happens.

No the heat never goes away. I 100% agree with you on going back to a standard volume water pump. I am seriously trying to avoid having to do that because as we all know changing the water pump on a foxbody is a pain especially with a Novi 2000

 

[rd]

I would have gone with a rad upgrade before a water pump. Is there any chance you are caught up in a reverse vs standard rotation issue? Did you add an intercooler in front of the rad?

Have had some issues getting my 79 Capri full of water over the years. Jacking the car, multiple fills, etc, seems to do it.

May want to check compression/head gaskets, as the sudden heating may be a symtom of a partial/intermittent leak. Had Windstar 3.8 experience with this.

 

[bdep73]

The rad is one of the first upgrades I did. the car curentlly has a mishimoto 3 core alluminum radiator so thats not the issue and the water pump is the correct reverse rotation pump. I am curious about what you mentioned with the haed gasket. I am pretty sure the head gaskets are fine because everythime I open the radiator the coolant level is full and I do not see or smell anything sweet coming out of the exhaust but mabye it's something i should look into further.

 

[mikestang63]

unscrew the water temp sending unit on the front driver side of the lower intake and then fill up the system until the coolant comes up to the threads of the sending unit opening. That point is higher than the radiator of the stat and should remove any air in the system. You can also get a thermostat housing with a removable pipe plug on it to bleed out the air. That is what I have and it works well.

 

[bdep73]

unscrew the water temp sending unit on the front driver side of the lower intake and then fill up the system until the coolant comes up to the threads of the sending unit opening. That point is higher than the radiator of the stat and should remove any air in the system. You can also get a thermostat housing with a removable pipe plug on it to bleed out the air. That is what I have and it works well.

I mentioned that I did exactly what you suggest in my original post. I also installed the thermostat housing with the plug and put another temp sensor in it for my autometer gauge. What happens when I tried to get the air out of them is theyf will bubble for a bit then coolant would come out then ten seconds later they would bubble again. This would literary go on all day with the air never fully coming out.

 

[mikestang63]

is one of your hoses collapsed or do you have a restriction. Have you pressure tested the system.

 

[bdep73]

is one of your hoses collapsed or do you have a restriction. Have you pressure tested the system.

the hoses are all new I put the mishimoto red silicone hose kit on the car. I know for sure the two main hoses are not collapsed but I would have to double check the bypass hose and the heater hose because they went on pretty tight. I didn't even think that that could be the problem until you just said it, great idea. As far as pressure testing the system I have not done that yet I was going to do that when we get some better weather here in CT.

 

[mikestang63]

also, is your overflow line hooked up and not restricted.

 

[bdep73]

also, is your overflow line hooked up and not restricted.

yea thats ok. I'm hoping the issue is the bypass hose because that is the only hose that I didn't really like the way it fit but it never dawned on me that it could be the cause of the whole problem. thanks again I appreciate the help.