Chevy Nova Forum banner

1 - 9 of 9 Posts

·
Registered
Joined
·
928 Posts
Discussion Starter #1
Today I filled up all the fluids and started my engine for the first time ( with fluids), its a brand new LS3 with a new Holly water pump. It climbed to 220 within five minutes, fans came on at 195 but the radiator and upper and lower hoses were cool. Put a gallon through the top radiator hose and ran again after it cooled off. Again got up up to 220 within 5 minutes. This time upper hose is hot but rad and lower hose are cool. There doesnt seem to be any circulation. Water pump is pretty simple and it is spinning. Only other thing I guess is the thermostat but if that is stuck closed shouldn't the lower hose also be hot since that is where the tstat is> Any thoughts? Anyone running the Holly serpentine systm with their waterpump?
 

·
Registered
Joined
·
55 Posts
You probably have it air locked. There is a special funnel that inserts into the fill neck that helps to burp out the air. RTR
 

·
Registered
Joined
·
1,114 Posts
I had the same problem on my LS1. I ended up pumping water through the steam vent line and it cured the problem. i pumped untill it came out of the upper hose. I used a cheap hand pump from harbor freight.

Tim
 

·
Registered
Joined
·
2,256 Posts
Sounds like air in the system, I would burp it!
 

·
Registered
Joined
·
928 Posts
Discussion Starter #6
I hate posts that don't give the resolution so here it is. These engines need to be vacuum filled.
 

·
Registered
Joined
·
1,049 Posts
How do you have the line for the steam ports routed?

I've never had to "vacuum fill" an LSx that maintains the OE coolant and steam vent designs.
 

·
Registered
Joined
·
1,596 Posts
I hate posts that don't give the resolution so here it is. These engines need to be vacuum filled.
I’ve never had issues with air in LS cooling system. Just as long as the radiator neck or surge tank is the highest spot in the cooling system, the air will escape from there. I just fill them up with a funnel attached to the radiator or the surge tank. You can get this funnel at oreilly’s or any other parts store I’m sure. The one I have is yellow. With a few different attachments for import and domestic radiators. Attach the funnel and fill the system up. Let the engine idle for a few minutes keeping a close eye on the coolant level in the funnel
 

·
Registered
Joined
·
928 Posts
Discussion Starter #9 (Edited)
I’ve never had issues with air in LS cooling system. Just as long as the radiator neck or surge tank is the highest spot in the cooling system, the air will escape from there. I just fill them up with a funnel attached to the radiator or the surge tank. You can get this funnel at oreilly’s or any other parts store I’m sure. The one I have is yellow. With a few different attachments for import and domestic radiators. Attach the funnel and fill the system up. Let the engine idle for a few minutes keeping a close eye on the coolant level in the funnel
I used the fancy funnel from Oreillys, it did not work. The engine was new and never had coolant in it. Radiator neck is higher and the steam port is routed correctly to the radiator. With the thermostat on the lower hose, I could not get water into the engine. Spoke with a shop that specialized in LS hot rods, they told me it needed to be vacuum filled, I borrowed a vacuum filler and it took an additional 1.5 gallons of coolant. Runs great, problem solved. It's also a great way to know if you have any leaks before you put coolant in as it has to hold a vacuum for 25 seconds, it's also easier to add the coolant. They are fairly cheap, under 50 bucks, its the only way I'll do it in the future.
 
1 - 9 of 9 Posts
Top