Coolant fill 1993
03-28-2017, 05:13 AM
#1
Coolant fill 1993
First of all, heads/cam swap and the block was drainied of coolant via shop vac and refilled via the water pump t-stat opening, then the coolant res until full.
Bought a new 180* t-stat as the old one was garbage, it didnt open at all in a pot of boiling water.
I've filled the res as much as it would go and when engine running let the thermostat bleeder out until coolant was flowing out of it, i then let it heat up to about 84C with the rad cap off
Even when the digital readout was at 84C, the lower hose (the passenger side, connects from rad to thermsotat housing on WP) was barely warm at all, i think there is seriously something wrong as this hose doesn't heat AT ALL literally, the drivers side (upper hose) was extremely hot, same as the heater core hoses, radiator itself was very warm. In the coolant reservoir, - i can see coolant moving so the pumps doing something... but i dont think the tstat is opening at all. I know it's a reverse flow system and temperamental as all hell but i did follow shbox's guide for F-Body lt1's on filling coolant, it's mostly the same. What am i doing wrong?
Am i just paranoid? should i leave it run hotter than 84-85C and see what happens? i expect both hoses to be very hot by the time the stat reaches rated temps but this is not the case. it's a brand new t-stat and i tested it in a pot of water so it is definitely working, it just doesn't seem right so here i am. Even the analogue gauge was fairly normal (And it is directly plumbed into the heads coolant passages) but the heads seemed to be extremely hot, as if filled with air in the coolant passages.
After rebuilding this engine and having three bolt threads strip in various places (and figuring out how to repair them) i am so over aluminium and can only imagine heads warping if i push it, in theory if it's full of air you can't trust the temp gauges, this is my first rebuild so go easy on a nooby, i'm here to learn how to do it myself but would prefer to not destroy $4k worth of cylinder heads (Australian problems).
That said, it seems to run very well untuned with a cam swap, i'm going to organise new 30# injectors plus a retune shortly.
Bought a new 180* t-stat as the old one was garbage, it didnt open at all in a pot of boiling water.
I've filled the res as much as it would go and when engine running let the thermostat bleeder out until coolant was flowing out of it, i then let it heat up to about 84C with the rad cap off
Even when the digital readout was at 84C, the lower hose (the passenger side, connects from rad to thermsotat housing on WP) was barely warm at all, i think there is seriously something wrong as this hose doesn't heat AT ALL literally, the drivers side (upper hose) was extremely hot, same as the heater core hoses, radiator itself was very warm. In the coolant reservoir, - i can see coolant moving so the pumps doing something... but i dont think the tstat is opening at all. I know it's a reverse flow system and temperamental as all hell but i did follow shbox's guide for F-Body lt1's on filling coolant, it's mostly the same. What am i doing wrong?
Am i just paranoid? should i leave it run hotter than 84-85C and see what happens? i expect both hoses to be very hot by the time the stat reaches rated temps but this is not the case. it's a brand new t-stat and i tested it in a pot of water so it is definitely working, it just doesn't seem right so here i am. Even the analogue gauge was fairly normal (And it is directly plumbed into the heads coolant passages) but the heads seemed to be extremely hot, as if filled with air in the coolant passages.
After rebuilding this engine and having three bolt threads strip in various places (and figuring out how to repair them) i am so over aluminium and can only imagine heads warping if i push it, in theory if it's full of air you can't trust the temp gauges, this is my first rebuild so go easy on a nooby, i'm here to learn how to do it myself but would prefer to not destroy $4k worth of cylinder heads (Australian problems).
That said, it seems to run very well untuned with a cam swap, i'm going to organise new 30# injectors plus a retune shortly.
Last edited by Hive; 03-28-2017 at 05:20 AM.
03-28-2017, 07:43 AM
#2
Racer
When refilling the cooling system fill at the radiator surge tank until a solid stream of 50/50 coolant mix comes out the bleed valves. Close bleed valve. Then top off the surge tank to the base of the neck.
Start the engine and run for four minutes, fill the surge tank until the level is maintained at the base of the neck. After four minutes or once level is maintained shut off.
Allow the engine to heat cycle (up to 195F/93C & down to 80F/27C) three times before driving aggressively. I usually do this at an idle. After each cool down top off the surge tank to the base of the neck and not to the top.
I like to check the bleed valve on the thermostat neck for trapped air between heat cycles.
Once the level is maintained on the surge tank stop removing the cap and check your level at the coolant recovery reservoir. The level should be maintained between the COLD and HOT marks.
Having the front end on ramps has helped me in the past with bleeding air.
If after heat cycling and air bleeding you still have issues you'll have to do some troubleshooting..
The thermostat usually opens at a temperature higher than its rating.
Recommend you get a FSM (Field Service Manual). Use the search function with key words (bleeding, flushing, cooling system, etc.) might be helpful also.
I hope this helps.
Start the engine and run for four minutes, fill the surge tank until the level is maintained at the base of the neck. After four minutes or once level is maintained shut off.
Allow the engine to heat cycle (up to 195F/93C & down to 80F/27C) three times before driving aggressively. I usually do this at an idle. After each cool down top off the surge tank to the base of the neck and not to the top.
I like to check the bleed valve on the thermostat neck for trapped air between heat cycles.
Once the level is maintained on the surge tank stop removing the cap and check your level at the coolant recovery reservoir. The level should be maintained between the COLD and HOT marks.
Having the front end on ramps has helped me in the past with bleeding air.
If after heat cycling and air bleeding you still have issues you'll have to do some troubleshooting..
The thermostat usually opens at a temperature higher than its rating.
Recommend you get a FSM (Field Service Manual). Use the search function with key words (bleeding, flushing, cooling system, etc.) might be helpful also.
I hope this helps.
The following users liked this post:
Hive (03-28-2017)
03-28-2017, 07:50 AM
#3
When refilling the cooling system fill at the radiator surge tank until a solid stream of 50/50 coolant mix comes out the bleed valves. Close bleed valve. Then top off the surge tank to the base of the neck.
Start the engine and run for four minutes, fill the surge tank until the level is maintained at the base of the neck. After four minutes or once level is maintained shut off.
Allow the engine to heat cycle (up to 195F/93C & down to 80F/27C) three times before driving aggressively. I usually do this at an idle. After each cool down top off the surge tank to the base of the neck and not to the top.
I like to check the bleed valve on the thermostat neck for trapped air between heat cycles.
Once the level is maintained on the surge tank stop removing the cap and check your level at the coolant recovery reservoir. The level should be maintained between the COLD and HOT marks.
Having the front end on ramps has helped me in the past with bleeding air.
If after heat cycling and air bleeding you still have issues you'll have to do some troubleshooting..
The thermostat usually opens at a temperature higher than its rating.
Recommend you get a FSM (Field Service Manual). Use the search function with key words (bleeding, flushing, cooling system, etc.) might be helpful also.
I hope this helps.
Start the engine and run for four minutes, fill the surge tank until the level is maintained at the base of the neck. After four minutes or once level is maintained shut off.
Allow the engine to heat cycle (up to 195F/93C & down to 80F/27C) three times before driving aggressively. I usually do this at an idle. After each cool down top off the surge tank to the base of the neck and not to the top.
I like to check the bleed valve on the thermostat neck for trapped air between heat cycles.
Once the level is maintained on the surge tank stop removing the cap and check your level at the coolant recovery reservoir. The level should be maintained between the COLD and HOT marks.
Having the front end on ramps has helped me in the past with bleeding air.
If after heat cycling and air bleeding you still have issues you'll have to do some troubleshooting..
The thermostat usually opens at a temperature higher than its rating.
Recommend you get a FSM (Field Service Manual). Use the search function with key words (bleeding, flushing, cooling system, etc.) might be helpful also.
I hope this helps.
Last edited by Hive; 03-28-2017 at 07:51 AM.
03-28-2017, 11:01 PM
#4
Ok got it up to 90C and the stat opened 
, i've left it at that, topped it up in both the res and surge tank, put the cap on and will let it cool. No further air coming out of the bleeder.
Interestingly, that split BLM is still there but only at some idle speeds.
TunerproRT - 900RPM. Map 65
Left bank BLM 160
Right bank BLM 108
I imagine the computer is just re-learning? I had the battery unplugged for a few hours prior, it was in closed loop, after a few revs it seems to clear up that split BLM and sat at 675RPM, both banks 108BLM (Subtracting fuel) Obviously untuned and it smelled a little bit rich. No misfire detection with the 1993.
That split BLM completely goes away with the slightest throttle press. Thinking about this, when i yanked the old heads some of the exhaust valves were white, some werent - related?
, i've left it at that, topped it up in both the res and surge tank, put the cap on and will let it cool. No further air coming out of the bleeder.Interestingly, that split BLM is still there but only at some idle speeds.
TunerproRT - 900RPM. Map 65
Left bank BLM 160
Right bank BLM 108
I imagine the computer is just re-learning? I had the battery unplugged for a few hours prior, it was in closed loop, after a few revs it seems to clear up that split BLM and sat at 675RPM, both banks 108BLM (Subtracting fuel) Obviously untuned and it smelled a little bit rich. No misfire detection with the 1993.
That split BLM completely goes away with the slightest throttle press. Thinking about this, when i yanked the old heads some of the exhaust valves were white, some werent - related?
Last edited by Hive; 03-28-2017 at 11:08 PM.
03-29-2017, 11:38 AM
#5
Should have pulled your knocks you left a whole bunch of crap in there.
03-29-2017, 07:15 PM
#6
Melting Slicks
I agree you should pull the knock sensors and properly drain the coolant from the engine block... rinse water through while they are out.
Also the normal operating temperature for your 1993 will be
90-100 degrees C
or
194-212 degrees F
Do some reading on the cooling systems of the LT1 (reverse flow) and you will see that even higher temperatures than these are considered to be in the "normal" range. Just keep the cooling system healthy and keep up on routine maintenance and you shouldn't have any issues.
Also the normal operating temperature for your 1993 will be
90-100 degrees C
or
194-212 degrees F
Do some reading on the cooling systems of the LT1 (reverse flow) and you will see that even higher temperatures than these are considered to be in the "normal" range. Just keep the cooling system healthy and keep up on routine maintenance and you shouldn't have any issues.
The following users liked this post:
Hive (03-29-2017)