Purging coolant system
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From: Hudsonville, MI
Purging coolant system Hey guys. Been putzing the Oldsmobile around, I am having an issue with the cooling system. The temperature will inconstantly vary at idle and slow cruise, sometimes it will get real hot before I have to shut it down, other times it stays at about 180*. Sometimes when it gets hot the temp will randomly just drop 20* from say 210* to 190*, then it heats up again or might stay there. I have a SLP 160* stat in it but it will not stay near 160*.
I think I have gotten all the air out of the system, I ran a hose from the steam crossover about 1' above the heads and let the car warm, it puked a bunch of air and coolant, then it got to 230* so I shut it down.
My initial thoughts are maybe a bad T-stat? Its brand new so it could be bad I suppose, second thought is still more air in the system. How do you purge the system? I filled it through the upper water pump hose port.
I think I have gotten all the air out of the system, I ran a hose from the steam crossover about 1' above the heads and let the car warm, it puked a bunch of air and coolant, then it got to 230* so I shut it down.
My initial thoughts are maybe a bad T-stat? Its brand new so it could be bad I suppose, second thought is still more air in the system. How do you purge the system? I filled it through the upper water pump hose port.
Last edited by ryanvv355; Mar 25, 2009 at 12:56 AM.
I am running the stock T-stat in my 5.3 and my temp stays at about 192 all the time.. I did not do anything to purge my coolant system..do you have a catch can that the system can pull the coolant back from?
I filled my system as much as possible through the radiator, then through the upper water pump connection, drove it let it cooled down and topped it off at the radiator. I had to top it off a couple of times.
Where is your steam vent hose routed to again?
Where is your steam vent hose routed to again?
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From: Hudsonville, MI
I if i pop my upper hose off the water pump, the water line is visible just below the bend in the outlet, so I know the block is full. My coolant bypass is routed to a barb welded on the outlet neck.
There are bubbles coming out of the rad. cores if i look into the cap hole, I'm hoping it is not a head gasket or cracked head/block. I will run a compression check tonight after work.
There are bubbles coming out of the rad. cores if i look into the cap hole, I'm hoping it is not a head gasket or cracked head/block. I will run a compression check tonight after work.
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From: Downers Grove, IL
Try topping it off through the heater hoses. Yes I know how crazy that sounds
. but once when I was refilling my el camino it would not stop overheating. I had filled it through the upper rad hose like usual and had topped the rad probably 2-3 times but it was still spiking to over 230 degrees. Finally out of frustration I opened the cap on the flush T in the heater hose and noticed it was empty. Stuck a funnel in and dumped almost a half gallon in......then all of a sudden it cooled just fine
. I have no idea why it was airbound like that but it seemed to fix the problem. I have refilled the cooling system once since then and I filled it through the upper rad hose which worked fine. I have no idea why it didn`t work that time and filling through the heater hose did.
. but once when I was refilling my el camino it would not stop overheating. I had filled it through the upper rad hose like usual and had topped the rad probably 2-3 times but it was still spiking to over 230 degrees. Finally out of frustration I opened the cap on the flush T in the heater hose and noticed it was empty. Stuck a funnel in and dumped almost a half gallon in......then all of a sudden it cooled just fine. I have no idea why it was airbound like that but it seemed to fix the problem. I have refilled the cooling system once since then and I filled it through the upper rad hose which worked fine. I have no idea why it didn`t work that time and filling through the heater hose did. LS1 Tech Stories
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Try jacking the front end of the car up so that the radiator cap is the highest point in the system
When I filled mine I unbolted one of the steam vent lines. Don't know if that made a difference in getting all the air out, but it sure made it fill faster.
By the way, placing the T stat in a pot of water with a kitchen thermometer will tell you if it is opening at the right temp.
When I filled mine I unbolted one of the steam vent lines. Don't know if that made a difference in getting all the air out, but it sure made it fill faster.
By the way, placing the T stat in a pot of water with a kitchen thermometer will tell you if it is opening at the right temp.
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From: Hudsonville, MI
Turned the heater on last night and let it warm up, it hit 209* then fell to 191 where it stayed for a minute. I held the car at 2700rpm for 3-4 minutes and it actually lowered the temp to 179*, where it stayed for about 15 more minutes at idle. I think the heater circuit may have been full of air causing the problem. I'm gonna try it again tonight and see what happens.
