Hi Guys...My motor has less than 5K on a complete rebuild. Been running great, boosting to 18 psi on a SP61GT Turbo. Here's my question (I've never seen this) and was wondering if it was a cause for concern.
On a dead cold start, coolant temp is at zero as expected. Car warms up, coolant temp gauge rises to about the 4 O'clock position. Stays there for a few minutes, then suddenly drops to a little less than the 5 O'clock position. Stays there for about a minute, then rises back to the 3:30-4 O'clock position and stays there rock steady. It never rises above this position under any driving conditions and I am not losing coolant at all. The system is not leaking anywhere on the car. The heater works normally.
When I shut the car off after the 1st run and restart (even after a few hours), it goes to 3:30-4 O'clock position fairly quickly and stays with no momentary drop. The only time it does this is after a dead cold start-up.
I have a CSR radiator, FAL twin fans w/ a variable speed controller (come on & off normally), and a 180 deg thermostat. The water pump is new...no weep hole leaks. I'm running Toyota Red coolant (60-40 mix) w\ Redline Water Wetter.
I was thinking when the thermostat opened up, it was allowing the cold coolant in the block as it should. The CSR radiator is a dual core...probably has close to double the capacity (I haven't measured it) of the stocker. The higher volume of coolant is taking longer to heat up, hence the drop in temp as seen on the gauge for a minute as the coolant circulates and gets heated up. Only thing my pea brain could come up with to explain this behavior. :dunno:
What do you guys think? Seen this one before? :icon_conf
On a dead cold start, coolant temp is at zero as expected. Car warms up, coolant temp gauge rises to about the 4 O'clock position. Stays there for a few minutes, then suddenly drops to a little less than the 5 O'clock position. Stays there for about a minute, then rises back to the 3:30-4 O'clock position and stays there rock steady. It never rises above this position under any driving conditions and I am not losing coolant at all. The system is not leaking anywhere on the car. The heater works normally.
When I shut the car off after the 1st run and restart (even after a few hours), it goes to 3:30-4 O'clock position fairly quickly and stays with no momentary drop. The only time it does this is after a dead cold start-up.
I have a CSR radiator, FAL twin fans w/ a variable speed controller (come on & off normally), and a 180 deg thermostat. The water pump is new...no weep hole leaks. I'm running Toyota Red coolant (60-40 mix) w\ Redline Water Wetter.
I was thinking when the thermostat opened up, it was allowing the cold coolant in the block as it should. The CSR radiator is a dual core...probably has close to double the capacity (I haven't measured it) of the stocker. The higher volume of coolant is taking longer to heat up, hence the drop in temp as seen on the gauge for a minute as the coolant circulates and gets heated up. Only thing my pea brain could come up with to explain this behavior. :dunno:
What do you guys think? Seen this one before? :icon_conf
