Overheat/Cooling system
 

Alright, I previously had what I thought was an issue with my coolant temp being far too low. It was reading 120F however, I determined that it was actually being read in C which would put it at 235F YIKES!

I'm quite confident that I have set the cooling system up incorrectly.

My system is the Stock 84 3 row rad, clutch fan (mechanical), heater core, and engine block. That is it..

I have the 84 overflow tank in there with some fluid to just bury the hose, but it never sees any thing else. I have tested the t-stat and it functions correctly and the water pump also functions correctly.

Did some searching on the forums and my steam line is going to a nipple that is slightly below the rad cap on the Pass side. Apparently this isn't the place to do it?

My questions are:
1) Is that steam line location fine or no?
2) should I actually have a recovery tank instead of an over flow and if YES how should I plumb it in? maybe a diagram?
3) It is also possible that my clutch fan is not operating correctly as well.. It should stop spinning when I shut the engine off when at temp correct?

Thank you in advance

2007 LH6 5.3L

Re: Overheat/Cooling system
 

Ideally the steam can go to the highest location possible, or into flow that feeds to the high point. I actually have mine running into a heater core hose. Once the initial air is out of the system, the steam lines don't do much, but were air to get into the system again, it could hot spot.

With all that, I doubt the steam line alone is causing that high temp. Unless you got a hotspot right where the sender was, the lines themselves don't really cause overheating.

I have an overflow only, not a recovery. As long as your maintaining full fluid volume at normal-high temps (i.e. not puking fluid out the overflow), you should be fine. Where is your overflow plumbed in? The nipple you described the steam line hooking to, seems like the place where my overflow comes off.

You should be able to just watch the thing idle and verify that fluid is circulating, and that the fan is turning on and off as needed.

Re: Overheat/Cooling system
 

I know for a fact the steam line is not the one causing the issue, was more curious if it was plumbed into the right spot, however possible there could be a slight contribution to this because of improper plumbing.. However, quite confident that my clutch fan is not working properly.. It continues to spin after the truck is turned off.. but that does not account for the high temps AT highway speeds... the fan would be doing little at those speeds its more or less for idle and low speed situations No?

The nipple below where I plumbed the steam line in, is the one going to the overflow tank on my set up? incorrect?

Re: Overheat/Cooling system
 

Are you sure you have all the air out of the engine . The ls engines can be difficult to get all the air out and do exactly what you have going on . You may just think you have it purged .

Heres a thread just not long ago with the same problem . http://67-72chevytrucks.com/vboard/s...t=over+heating

Re: Overheat/Cooling system
 

I agree I had a buddy at work changed his water pump on his Tahoe. He was having issues. We talked several hrs and finally found that taking the steam ports loose and filling the motor up until water started coming out of the connections fixed it. he had tried everything else.

I also had a little trouble with my swap when it first started up getting all the air out of the system. We had it on a lift and had the front as high as we could get it with out dragging the back bumper before we got all the air pockets out of it.:chevy:

Re: Overheat/Cooling system
 

Post a pic of this. Theres no way you could get a steam line higher than the nipple for the overflow. That said, I dont think that is your problem though. How is your radiator? Sounds like it may be plugged up or isnt getting enough air flow through it.

Re: Overheat/Cooling system
 

i just had a similar problem, my fix was filling the top radiator hose with coolant then topping off radiator. on my setup i tapped steamline back into water pump, but i ran engine until coolant shot out of steam line, then reconnected it. Haven't had probs since

Re: Overheat/Cooling system
 

X2, I had to fill my cooling system via the upper hose to get rid of my air pocket. Or you can vacuum fill the cooling system.

Re: Overheat/Cooling system
 

Before installing my engine I had high Temps running the motor on a stand. Turned out to be motor was positioned too high or radiator was too low. Upper radiator mouth was lower than mouth on motor. I raised radiator and all was solved. Unsure if this mis alignment Is possible once dropped in vehicle.