temp keeps going up slowly but steady

[dutch]

I just came back from my first 10 mile trip. 
The temp keeps slowly crawling up... very little idling on this trip and cool weather too.  parked the car in the driveway and it puked a bunch of coolant 
I was wondering what would cause this.  First thing that caught my attention is the fan clutch.  Isn`t that thing supposed to turn light when the engine is cold and hard when hot...?   it turns super light when hot...   

[72cudamaan]

Thermal fan clutch is hard when cold. As it heats up and the car goes faster, there should be less need for the fan to turn
as there is more air being passed across the radiator anyway. So it should freewheel more at higher rpm's

[72cudamaan]

Maybe just air in the system? Sticky stat?

[dutch]

hm... new stat and I drilled a small hole in it to get rid of the air up there 

[Bullitt-]

Thermal fan clutch is hard when cold. As it heats up and the car goes faster, there should be less need for the fan to turn
as there is more air being passed across the radiator anyway. So it should freewheel more at higher rpm's

Am I the only one that thinks this is bass-ackwards?......no need for fan when cold

That being said you may need a new clutch fan but the fan has little to do with cooling at highway speeds. I'm guessing you have flow issues, either coolant or air.

[Strawdawg]

does the fan seem to be pulling air thru the radiator as it should?  Does the air flow increase immediately when you blip the throttle?  Got a shroud on it and is the fan positioned properly in the shroud  so it is not too far inside the shroud or not deep enuf...?

[dutch]

Am I the only one that thinks this is bass-ackwards?......no need for fan when cold

That being said you may need a new clutch fan but the fan has little to do with cooling at highway speeds. I'm guessing you have flow issues, either coolant or air.

that was my idea as well...  when driving @ say 50mph the temp seems pretty stable. 

just looked into the cooler and there`s junk in the channels, so that could very well be the problem. It`s not glogged up all the way but no 100% passage either.  The block was hot tanked before rebuild, but the rad has nothing done to it other than a flush before installation. 

[dutch]

does the fan seem to be pulling air thru the radiator as it should?  Does the air flow increase immediately when you blip the throttle?  Got a shroud on it and is the fan positioned properly in the shroud  so it is not too far inside the shroud or not deep enuf...?

fan is about half way into the shroud.  I haven`t tested the airflow.

[4 speed fish]

I think you have air in the system.I would  idle the car between 1800 and 2000 rpm's with the radiator cap off and let the system burp.I had the same issue and this work for me.A friend of mine once ran water with a hose with some pressure starting from the lower radiator hose to flush the system in the reverse order.

[Strawdawg]

http://www.haydenauto.com/upload/HaydenAuto/Documents/Cat_Imperial/2007-imperial-fan-clutches.pdf

If the car runs cool at 50 then it seems you don't have enough air flow at lower speeds...But if the tubes in the radiator are plugged very much, then I would guess that is a problem and perhaps, the primary problem.

If the clutch is working as per the above link, then I would think the fan is doing its job but I would check it as I suggested and see if immediately pulls more air, or does it gradually increase air flow, or not at all, when the rpm is brought up

[BS CUDA]

I think you have air in the system.I would  idle the car between 1800 and 2000 rpm's with the radiator cap off and let the system burp.I had the same issue and this work for me.A friend of mine once ran water with a hose with some pressure starting from the lower radiator hose to flush the system in the reverse order.

  I also jack the front end of the car up so the rad cap is the highest point - seems to assist in flushing the air.

[brads70]

Just wondering... who's/what water pump are you using?  Mind you it sounds like the clutch fan is buggered up?

[dutch]

some good points here 
so how do I know for sure all air is gone?

[BS CUDA]

some good points here 
so how do I know for sure all air is gone?

I use this procedure even with a stock rad. When you are at the top up portion of the procedure with the rad cap off you can see the air bubbling out. It may take a minute or it may take 10 minutes for it to completely disappear. You will see the flow of coolant smooth out and all bubbles disappear. I always purge with the front end in the air!!

 http://db.becool.com/assets/downloads/owners_manual.pdf

[Bullitt-]

that was my idea as well...  when driving @ say 50mph the temp seems pretty stable. 

just looked into the cooler and there`s junk in the channels, so that could very well be the problem. It`s not glogged up all the way but no 100% passage either.  The block was hot tanked before rebuild, but the rad has nothing done to it other than a flush before installation. 

Years ago mine would be good up to about 55 on a hot day but if I drove any faster the temp would climb then would overheat if I had to stop in traffic. Clogged radiator was the problem, replaced with a 3-core and now it runs cool all the time. You might have a shop boil yours out, have it rodded or re-cored.