Correct water temp???
Discussion
I recently experienced issues with the Ultima running hot. The coolant boiled out a few weeks ago, but I found out that the caps were on the wrong pots, so I figured that is what caused it.
I switched the caps to the correct side this weekend after filling everything up with coolant. I left the swirl pot cap off, and ran the car filling it with coolant as it ran. The coolant seems to be circulating through the system fine, since while the engine is up to temp and running there's a pretty big amount of coolant coming back into the swirlpot from the engine.
However, I never really paid attention to what the 'normal' and 'correct' temp should be, so now I don't know if it's still running hot or not. It seems to settle in the 100-110 mark on the gauge. Is this normal, or still hot???
I have already checked hoses, and the thermostat seems to be opening based upon the amount of coolant circulating back into the swirlpot, but for some reason it still seems like it's running hot. Any other suggestions???
Thanks!
I switched the caps to the correct side this weekend after filling everything up with coolant. I left the swirl pot cap off, and ran the car filling it with coolant as it ran. The coolant seems to be circulating through the system fine, since while the engine is up to temp and running there's a pretty big amount of coolant coming back into the swirlpot from the engine.
However, I never really paid attention to what the 'normal' and 'correct' temp should be, so now I don't know if it's still running hot or not. It seems to settle in the 100-110 mark on the gauge. Is this normal, or still hot???
I have already checked hoses, and the thermostat seems to be opening based upon the amount of coolant circulating back into the swirlpot, but for some reason it still seems like it's running hot. Any other suggestions???
Thanks!
It seems like the coolant is overflowing when the car is running, so after the engine cools down both pots are fairly empty.
Good question about the fans.....I don't know what temp they kick in, but they do both come on. However, even with the fans continuously running, when the car sits still and idles it seems to be running hot.
What's the correct max temp supposed to be on the gauge??
Good question about the fans.....I don't know what temp they kick in, but they do both come on. However, even with the fans continuously running, when the car sits still and idles it seems to be running hot.
What's the correct max temp supposed to be on the gauge??
Edited by ILuv4REs on Monday 20th April 21:48
Well X8 used to run all day at 85 degrees C in flowing air. As soon as you came to traffic it would go up quite fast and the fans would kick in at indicated 98 (ish). The temp would continue to rise for a minute or so and then fall to 90 where it would sit even static.
When the engine was cold and the caps removed, you'd see a full swirl pot and a 1/4 full expansion tank. Much more than that in the expansion tank and it would find it's own level by spirting out to ground.
I take it you are taking this reading with the caps both on? You aren't just letting the water flow round without it pressurising?
When the engine was cold and the caps removed, you'd see a full swirl pot and a 1/4 full expansion tank. Much more than that in the expansion tank and it would find it's own level by spirting out to ground.
I take it you are taking this reading with the caps both on? You aren't just letting the water flow round without it pressurising?
I think the swirl pot should be full when all has cooled overnight . Try topping up and checking again . Mine is circa 500 HP and runs at 85 but there again has matching rad' . I would take the thermostat out and test in a kettle with accurate thermometer . The opening value should be the same as stamped on the thermostat . It's difficult to say if you don't know what you previously ran at . I tested my sensor [+ gauge in situ ] in a kettle of water with a lab thermometer and the engine running to ensure same voltage as when driving . The gauge read 100 at 95 on the sensor . Obviously you have to put a bung in where you take the sensor out of . Your gauge may be "high " like mine . All very fiddly but interesting .
Frank
Frank
These little hand-held infrared thermometers are really useful to track heat accurately....used one to cycle my new block.
If its an ongoing problem after all else checks out, the adjustable fan stats seem to be a good, proven option.
I'm still of the opinion that positioning the fan switch nearer the heat source (engine) will work in higher output installations. The Ultima rad will not be quite as effective as an upright example.
I think I read 79'C was supposed to be optimal for the small block.
If its an ongoing problem after all else checks out, the adjustable fan stats seem to be a good, proven option.
I'm still of the opinion that positioning the fan switch nearer the heat source (engine) will work in higher output installations. The Ultima rad will not be quite as effective as an upright example.
I think I read 79'C was supposed to be optimal for the small block.
Edited by 738 driver on Monday 20th April 22:56
If the swirl pot level is dropping then I suspect you have a faulty seal on the cap. The swirl pot level should be right to the brim unless all of the water has gone from the expansion.
If the seal is damaged then the system will not get up to pressure and that is why it will boil.
Steve
If the seal is damaged then the system will not get up to pressure and that is why it will boil.
Steve
GTRMikie said:
With a cold engine my expansion tank is empty, and the swirl pot level is about one inch down from the top. With a hot engine (80degs) the expansion tank is 1/3rd full. I have never had to top up the coolant (9 years!) but have replaced it a couple of times.
Whilst I accept you have not had any problems with this I would say it is not ideal. With air in the swirl pot there is the possibility of the water flow taking that air with it around the system.Steve
Steve_D said:
GTRMikie said:
With a cold engine my expansion tank is empty, and the swirl pot level is about one inch down from the top. With a hot engine (80degs) the expansion tank is 1/3rd full. I have never had to top up the coolant (9 years!) but have replaced it a couple of times.
Whilst I accept you have not had any problems with this I would say it is not ideal. With air in the swirl pot there is the possibility of the water flow taking that air with it around the system.Steve
GTRMikie said:
Steve_D said:
GTRMikie said:
With a cold engine my expansion tank is empty, and the swirl pot level is about one inch down from the top. With a hot engine (80degs) the expansion tank is 1/3rd full. I have never had to top up the coolant (9 years!) but have replaced it a couple of times.
Whilst I accept you have not had any problems with this I would say it is not ideal. With air in the swirl pot there is the possibility of the water flow taking that air with it around the system.Steve
I keep forgetting you're a special case.
Steve
I installed a new thermostat (they're not very expensive and I had to take it out to test anyways - so it seemed foolish not to just replace it!), and I also ordered new caps for both the swirl pot and expansion tanks from Ultima - they should be here today.
Hopefully, these simple things will fix the overflowing coolant issue!!!!!
Hopefully, these simple things will fix the overflowing coolant issue!!!!!
ILuv4REs said:
I installed a new thermostat (they're not very expensive and I had to take it out to test anyways - so it seemed foolish not to just replace it!), and I also ordered new caps for both the swirl pot and expansion tanks from Ultima - they should be here today.
Hopefully, these simple things will fix the overflowing coolant issue!!!!!
You can also fit a new radiator stat so that the fans come on earlier. This helped immensely with the GTR-S.Hopefully, these simple things will fix the overflowing coolant issue!!!!!
This does prompt another question for which I don't currently have an answer.
What is the correct thermostat temperature rating?
I have four books by Chevy experts and none of them talk much about the engine cooling system. The closest I can find is David Vizard advising that the most power can be had with a water temp of 170°F (77°C) and oil temp between 180°F (82°C) and 210°F (99°C). He does admit this is difficult to achieve and advises adding block filler up to the bottom of the core plugs.
From this I’m suspecting we should all be running lower stat temps and bringing the fans in early. I don’t even remember the temp my stat is so I think it has to come out shortly for investigation.
Certainly, from this, running up in the 100 degree area (which I have seen plenty of times) is not good but is likely to be when in traffic rather than when demanding full power. I will have to start monitoring motorway cruise temps as they will be the most stable and probably reflect the temp the stat is operating at.
Steve
What is the correct thermostat temperature rating?
I have four books by Chevy experts and none of them talk much about the engine cooling system. The closest I can find is David Vizard advising that the most power can be had with a water temp of 170°F (77°C) and oil temp between 180°F (82°C) and 210°F (99°C). He does admit this is difficult to achieve and advises adding block filler up to the bottom of the core plugs.
From this I’m suspecting we should all be running lower stat temps and bringing the fans in early. I don’t even remember the temp my stat is so I think it has to come out shortly for investigation.
Certainly, from this, running up in the 100 degree area (which I have seen plenty of times) is not good but is likely to be when in traffic rather than when demanding full power. I will have to start monitoring motorway cruise temps as they will be the most stable and probably reflect the temp the stat is operating at.
Steve
Turns out my radiator cap was bad. I ordered new caps from Ultima, and installed both of them along with a new thermostat & coolant fill. I even pressure tested the system.
BUT, since I never really looked at the temp before this issue, I am really interested to make sure all is ok.........
Does this sound about right???...........While driving around town, the temp is around 90 but goes up to 100 while sitting at a light. On the highway, it drops down to 85-90 range. Does this sound about where is should be???? (I have the 720 HP 406" aluminum small block) Thanks!
BUT, since I never really looked at the temp before this issue, I am really interested to make sure all is ok.........
Does this sound about right???...........While driving around town, the temp is around 90 but goes up to 100 while sitting at a light. On the highway, it drops down to 85-90 range. Does this sound about where is should be???? (I have the 720 HP 406" aluminum small block) Thanks!
738 driver said:
If you purchased the engine from a supplier, new, then you will likely have a dyno sheet.
I would try to match, or run a few degree's cooler than than the dyno run particularly as you are running an alloy block!
The Dyno was done with just the engine out of the car, not installed in the car. Wouldn't the engine installed run a bit hotter since it's now enclosed under the rear lid, plus I live in Florida which is much hotter outside air than in Indiana where the engine came from??I would try to match, or run a few degree's cooler than than the dyno run particularly as you are running an alloy block!
I was hoping if someone could confirm that around town or stopped at a red light a reading of 95-100, and highway reading of 85-95, is reasonable normal operating temps.
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