strange cooling problem
Thread Starter
Intermediate
Joined: May 2000
Posts: 36
Likes: 6
From: Hazelwood MO
strange cooling problem
Cooling system works very well--190ish in town, 180 highway--with the heater core in the circuit. Remove the heater core (turn off the heater) temp rockets to 235-40. Belts squeal like an abused hog. In traffic, highway, everywhere. Open heater core-temp drops back to normal, squeal stops, all in about 20 seconds!! Is it possible to hydro-lock a water pump? Missing some kind of by-pass? I'm confused.
82 Corvette
Dart SHP 412
AFR 195 comp
Clay Smith 3102 221 cam
Weiand Team G pump
Robert Shaw type 180* thermo.
Eldebrock XT+EFI
Dewitt rad
Spal fans
Painless controller
82 Corvette
Dart SHP 412
AFR 195 comp
Clay Smith 3102 221 cam
Weiand Team G pump
Robert Shaw type 180* thermo.
Eldebrock XT+EFI
Dewitt rad
Spal fans
Painless controller
Last edited by oldguy; Jun 6, 2017 at 08:25 AM.
Thread Starter
Intermediate
Joined: May 2000
Posts: 36
Likes: 6
From: Hazelwood MO
Where would this mysterious by-pass be located? All the parts seem to be pretty much standard configuration, has a plugged port on top of pump, heater feed out the side of the pump, return into intake--would appear to be normal setup. Something different about Dart SHP 400
block or Wieand Team G pump? AFR heads? Tee off heater return into top port on pump? Really confused.
Last edited by oldguy; Jun 6, 2017 at 09:43 AM.
Thread Starter
Intermediate
Joined: May 2000
Posts: 36
Likes: 6
From: Hazelwood MO
Le Mans Master
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Posts: 9,246
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From: Dryden MI
Thread Starter
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Joined: May 2000
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From: Hazelwood MO
Le Mans Master
Joined: Jan 2001
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From: Dryden MI
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Thread Starter
Intermediate
Joined: May 2000
Posts: 36
Likes: 6
From: Hazelwood MO
Yeah--me neither. But that is what is happening. Some discussion about a missing by-pass. Possibly from top of pump to port on manifold over by heater return. Whatever is going on causes the pump to lock up hard enough to make TWO belts squeal like a banshee.
Drifting
Joined: Oct 2005
Posts: 1,615
Likes: 150
From: Forth Worth TX
There should be a valve inline between the water pump and the heater core (vacuum operated?).
When you turn your Heater OFF, the valve is most likely blocking all water from flowing. Liquids don't compress. With the water flow blocked, the water pump is trying to compress water into the heater hose and it can't do that, the water pump comes to a grinding stop and there is no water "flow" through the engine. The water is just sitting still in the engine/system.
Did this problem just start out of the blue or did you do something to the car and then the problem occurred?
It certainly seems like the heater core is inline with the engines coolant system and when the heater core is turned OFF you are blocking all flow through the engine.
When you turn your Heater OFF, the valve is most likely blocking all water from flowing. Liquids don't compress. With the water flow blocked, the water pump is trying to compress water into the heater hose and it can't do that, the water pump comes to a grinding stop and there is no water "flow" through the engine. The water is just sitting still in the engine/system.
Did this problem just start out of the blue or did you do something to the car and then the problem occurred?
It certainly seems like the heater core is inline with the engines coolant system and when the heater core is turned OFF you are blocking all flow through the engine.
Last edited by Revi; Jun 6, 2017 at 11:59 AM.
Thread Starter
Intermediate
Joined: May 2000
Posts: 36
Likes: 6
From: Hazelwood MO
There should be a valve inline between the water pump and the heater core (vacuum operated?).
When you turn your Heater OFF, the valve is most likely blocking all water from flowing. Liquids don't compress. With the water flow blocked, the water pump is trying to compress water into the heater hose and it can't do that, the water pump comes to a grinding stop and there is no water "flow" through the engine. The water is just sitting still in the engine/system.
When you turn your Heater OFF, the valve is most likely blocking all water from flowing. Liquids don't compress. With the water flow blocked, the water pump is trying to compress water into the heater hose and it can't do that, the water pump comes to a grinding stop and there is no water "flow" through the engine. The water is just sitting still in the engine/system.
Question is will a by-pass hose from pump to intake do what needs to be done and still pass enough coolant thru the heater to make heat on a cold day. Don't drive much in cold- tires absolutely hate cold pavement- but still might need de-foggers some times. Some what less confused now
Trying to get ready for another dyno run. A little tweak here and there might be good for 10-15? hp or more??? Stay tuned.
Actually,in hindsight, problem has been here form the git-go. First start up belts made major racket. Eventually quieted down, but then opened the heater to purge air and never shut it off again until we started getting serious about tuning- Again. Didn't really notice any extra heat so just left it on. Shut it off because we could and the worms were out of the can!
Last edited by oldguy; Jun 6, 2017 at 12:19 PM.
Le Mans Master
Joined: Jan 2001
Posts: 9,246
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From: Dryden MI
The only thing in the 3/4 inch heater hose is a shut off valve. The 5/8 inch hose goes directly to the heater core. Could there be a problem with your radiator? Could the lower radiator hose be collapsing?. I am running the 78 with heater core bypassed until I change out leaking heater core.
The center of your water pump that is plugged might be part of the bypass, if it is a big block.
http://www.hotrodders.com/forum/bbc-...ke-195057.html
The center of your water pump that is plugged might be part of the bypass, if it is a big block.
http://www.hotrodders.com/forum/bbc-...ke-195057.html
Last edited by Cooter Tech; Jun 6, 2017 at 12:44 PM.
Burning Brakes
Joined: Apr 2008
Posts: 1,222
Likes: 93
From: shelbyville West Michigan
assume it's a small block?
which version of the Team G pump do you have, there are several.
are you using a spacer on the pump? is it on right, or is it blocking the internal bypass hole from the pump to the block?
possible the bypass is blocked, AND the thermostat is backwards or not functioning properly leaving low flow with the heater core blocked (which when open functions as a bypass as well).
is the pump correct rotation?
which version of the Team G pump do you have, there are several.
are you using a spacer on the pump? is it on right, or is it blocking the internal bypass hole from the pump to the block?
possible the bypass is blocked, AND the thermostat is backwards or not functioning properly leaving low flow with the heater core blocked (which when open functions as a bypass as well).
is the pump correct rotation?
Thread Starter
Intermediate
Joined: May 2000
Posts: 36
Likes: 6
From: Hazelwood MO
The only thing in the 3/4 inch heater hose is a shut off valve. The 5/8 inch hose goes directly to the heater core. Could there be a problem with your radiator? Could the lower radiator hose be collapsing?. I am running the 78 with heater core bypassed until I change out leaking heater core.
The center of your water pump that is plugged might be part of the bypass, if it is a big block.
http://www.hotrodders.com/forum/bbc-...ke-195057.html
The center of your water pump that is plugged might be part of the bypass, if it is a big block.
http://www.hotrodders.com/forum/bbc-...ke-195057.html
Drifting
Joined: Oct 2005
Posts: 1,615
Likes: 150
From: Forth Worth TX
It seems like your water pump isn't pumping any water directly through the engine block and all the water must first pass through the heater core before it gets to the engine block.
Sounds silly, but does explain the temp rise, belt squeal, etc. when the heater core is turned OFF.
Sounds silly, but does explain the temp rise, belt squeal, etc. when the heater core is turned OFF.
Thread Starter
Intermediate
Joined: May 2000
Posts: 36
Likes: 6
From: Hazelwood MO
assume it's a small block?
which version of the Team G pump do you have, there are several.
are you using a spacer on the pump? is it on right, or is it blocking the internal bypass hole from the pump to the block?
possible the bypass is blocked, AND the thermostat is backwards or not functioning properly leaving low flow with the heater core blocked (which when open functions as a bypass as well).
is the pump correct rotation?
which version of the Team G pump do you have, there are several.
are you using a spacer on the pump? is it on right, or is it blocking the internal bypass hole from the pump to the block?
possible the bypass is blocked, AND the thermostat is backwards or not functioning properly leaving low flow with the heater core blocked (which when open functions as a bypass as well).
is the pump correct rotation?
Thread Starter
Intermediate
Joined: May 2000
Posts: 36
Likes: 6
From: Hazelwood MO
It seems like your water pump isn't pumping any water directly through the engine block and all the water must first pass through the heater core before it gets to the engine block.
Sounds silly, but does explain the temp rise, belt squeal, etc. when the heater core is turned OFF.
Sounds silly, but does explain the temp rise, belt squeal, etc. when the heater core is turned OFF.
So now the question. So is the problem the Dart block, AFR heads or Weiand pump? Is the answer as simple as a by-pass hose ala big block? Getting confused again.