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No coolant flow
Thread Starter
Teching In
Joined: Oct 2005
Posts: 8
Likes: 0
From: Jackson, MI
No coolant flow Guys I need help. After a 9 week wait I finally got my Mast black label 427 for my 67' camaro. It's in and running but the coolant isn't flowing so the rad is cold but the motor is over heating. I ordered the motor with an F-body water pump and balancer but the thermostat housing I bought, for a 2000 camaro, didn't fit through the opening. I've looked at lots of pics and I'm sure the water pump is from an F-body. I ended up buying an LS2 thermostat and housing and it went together fine but I have no coolant flow. Any ideas? Of course it's Sunday so no tech support from Mast until tomorrow.
How much run time has this engine had ? I have had a few hard times getting the air burped out of the system allowing the coolant to flow. Most of the time after it cools down it will burp some bubbles and the coolant level in the radiator will drop. It takes a bit sometime, if you haven't already... Jack the car up slightly in the front, and try pumping the coolant hoses with the engine running. They also sell vacuum tools to pull air from the system as well, I bought one the last time I reinstalled the motor and it worked well.
You could also drain it into a clean pan and pull the T-stat out and try that if you think its suspect. But it will be a pain in the *** because you'll have to repeat it to replace the T-stat at some point.
You could also drain it into a clean pan and pull the T-stat out and try that if you think its suspect. But it will be a pain in the *** because you'll have to repeat it to replace the T-stat at some point.
Thread Starter
Teching In
Joined: Oct 2005
Posts: 8
Likes: 0
From: Jackson, MI
It hasn't run very long because it gets hot pretty quick. You may be on to something. The engine was cold so I popped the cap and it was a little low so I decided to jack up the front as high as my jack would go and was able to add over a gallon of coolant. Now the top radiator hose is getting hot but the bottom one is still cold. I guess I'll let it cool down again and see if it will take more. The fuel pressure was a little low too so I tweaked that up to 60 but I don't think that had much to do with it.
Try squeezing the radiator hose? I do that to help get air out. Sounds like you have a blockage some where but im sure thats what you are thinking already. Good luck tryn to figure it out.
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These LS engines are super sensitive to air locking. I had the same issue with my crate LS2 when I first started it. I tried removing the thermostat, radiator cap, etc. Basically you have water in the radiator that is sitting there and probably very little, if any, in the actual engine block.
I finally got things to flow by loosening a radiator hose and inserting a water hose in it which allows water to enter directly into the block. This also allows the air to escape as you do this.
Good luck.
I finally got things to flow by loosening a radiator hose and inserting a water hose in it which allows water to enter directly into the block. This also allows the air to escape as you do this.
Good luck.
These LS engines are super sensitive to air locking. I had the same issue with my crate LS2 when I first started it. I tried removing the thermostat, radiator cap, etc. Basically you have water in the radiator that is sitting there and probably very little, if any, in the actual engine block.
I finally got things to flow by loosening a radiator hose and inserting a water hose in it which allows water to enter directly into the block. This also allows the air to escape as you do this.
Good luck.
I finally got things to flow by loosening a radiator hose and inserting a water hose in it which allows water to enter directly into the block. This also allows the air to escape as you do this.
Good luck.
This is the correct answer that will most likely solve your problem. You MUST fill the block with coolant or the thermostat will have a hard time opening. I too pull the top hose and back-fill the block with coolant.
Can clarify what you have for the Water pump.. I know you said F-Body.. but what years / Gen ?.. .98-02 F-Body or 2010+ F-Body ?
You said the LS2 housing fit. Makes me think you have a mis-match issue with the water pump, housing and T-Stat.
The Gen III Thermostat does work differently from the old SBC. Do you have the Heater outlets routed to the core and able to flow ? or plugged ?
But yeah.. check to make sure you don't have an air pocket.. try the suggestion on filling the upper hose. Or you can also try loosening the steam bolts and let the air escape through it.
Good luck.
BC
You said the LS2 housing fit. Makes me think you have a mis-match issue with the water pump, housing and T-Stat.
The Gen III Thermostat does work differently from the old SBC. Do you have the Heater outlets routed to the core and able to flow ? or plugged ?
But yeah.. check to make sure you don't have an air pocket.. try the suggestion on filling the upper hose. Or you can also try loosening the steam bolts and let the air escape through it.
Good luck.
BC
Thread Starter
Teching In
Joined: Oct 2005
Posts: 8
Likes: 0
From: Jackson, MI
It's a 98-02 pump for sure. I picked up a 2000 Camaro T-stat and the ears on the housing were too wide to fit in the hole though. After reading that a 98-02 T-stat was too wide to fit a gen III/IV pump, I decided to try an LS2 T-stat and housing and it fit. The heater hoses were routed to the core and put out plenty of heat but no flow to the rad. Leaving the steam line loose while running the motor eventually worked.
can you elaborate a bit on leaving the steam line loose? If the radiator cap was off, wouldn't the steam line route right into the top of the radiator and into atmosphere anyway?
Where did you "loosen" it?
Where did you "loosen" it?
I just loosen it to help bleed the air and then tighten them back up once coolant starts to flow without any air escaping. I used the front cross over location on the front of the head.
Combining this with filling from the top raditor hose.. I have not had any problem of air trapped in the system.
Once the coolant is filled, top radiator is reconnected. I start up the engine to a high idle loosen to let the air out and the re tighten.
There are many procedures fir filling and for purging air out of the system... just research for them and use what works for you..
good luck
BC
Combining this with filling from the top raditor hose.. I have not had any problem of air trapped in the system.
Once the coolant is filled, top radiator is reconnected. I start up the engine to a high idle loosen to let the air out and the re tighten.
There are many procedures fir filling and for purging air out of the system... just research for them and use what works for you..
good luck
BC
Thread Starter
Teching In
Joined: Oct 2005
Posts: 8
Likes: 0
From: Jackson, MI
Here is the best pic I could get of the thermostat housing. The LS1 housing and T-stat are one piece and the LS2 housing and T-stat are separate. The pump looks like about every pic you see online of the LS1 pump.
Thread Starter
Teching In
Joined: Oct 2005
Posts: 8
Likes: 0
From: Jackson, MI
Loosen the cap screws that hold the steam line to the heads at the front of the engine. You can see them on both sides of the throttle body in this pic. I loosened them enough to let coolant dribble out and every once in awhile I would lift it a bit to increase flow. The cap was off the rad the whole time so I could see when it started flowing. It took a few minutes but it worked. It actually wasn't that messy. Most of the coolant ran down the front of the block and not on the valley cover.
Last edited by 67RS; Jun 24, 2014 at 10:04 PM.