Daily driver ’92 GT, DSS crate 306 motor, 303 cam, AFR heads, Vortech intake, 24# injectors, oversized aluminum radiator, stock type water pump, 5 1/4 in. drive pulley, new stock fan clutch, fan shroud installed. Coolant is fresh. When I bought this car late last summer, it had a dual electric fan unit installed, but I thought it still ran on the hot side. When the electric fan unit failed, I went back to the stock motor driven fan and the temps got a little cooler. But now that the daily temps are back up in the upper 90’s, the near-overheating is back.
So, when I’m moving at greater than 35-40 mph, the temp stays right in mid-range where it should be, even with the A/C going full blast. But, if I get in stop & go traffic for just a couple of minutes, or stop at one traffic light, the temp starts to rise rapidly, even if I turn the A/C off. Any more than a couple of minutes at those conditions, and the temp gets up toward the 270 reading, fast. Steadily holding a few extra revs on the engine doesn’t seem to have any effect one way or the other. Once I get back up to speed again, the temp drops rapidly back to mid-range. I know the stock gage is not the best, but I got coolant overflow once just as the gage hit the top, so I know it’s close.
Doesn’t seem to act like a sticky t-stat since the temp drops right back down when I get moving. Maybe a failing water pump? Should I go to a bigger size pulley? Or is there just not enough airflow through the radiator? It still has the stock-type GT front fascia, so maybe I need to install a Cobra-type front grill for better airflow? It also has a power steering fluid cooler installed in front of the A/C heat exchanger & radiator, which further reduces airflow. Should I remove this (don’t do enough rally type driving to warrant it, in my opinion)? Any ideas, anyone . . . anyone?
So, when I’m moving at greater than 35-40 mph, the temp stays right in mid-range where it should be, even with the A/C going full blast. But, if I get in stop & go traffic for just a couple of minutes, or stop at one traffic light, the temp starts to rise rapidly, even if I turn the A/C off. Any more than a couple of minutes at those conditions, and the temp gets up toward the 270 reading, fast. Steadily holding a few extra revs on the engine doesn’t seem to have any effect one way or the other. Once I get back up to speed again, the temp drops rapidly back to mid-range. I know the stock gage is not the best, but I got coolant overflow once just as the gage hit the top, so I know it’s close.
Doesn’t seem to act like a sticky t-stat since the temp drops right back down when I get moving. Maybe a failing water pump? Should I go to a bigger size pulley? Or is there just not enough airflow through the radiator? It still has the stock-type GT front fascia, so maybe I need to install a Cobra-type front grill for better airflow? It also has a power steering fluid cooler installed in front of the A/C heat exchanger & radiator, which further reduces airflow. Should I remove this (don’t do enough rally type driving to warrant it, in my opinion)? Any ideas, anyone . . . anyone?