Q:
What temperature thermistat came stock in the SS (L69)?
The stock thermistat used on the SS's L69 engine is rated at 195 degrees.
Q:
Can I use a cooler thermistat on the L69?
Yes, you can use a 180 degree thermistat without any worry of adverse side effects and
may even see slight performance improvement based on the lower regulated temperature.
Some use a 160 degree thermistat, but this is ill advised when used with the stock
ECM prom chip. With such a low temperature, it is possible that the ECM will not achieve
close loop operation temperature. You can get aftermarket proms which allow the use
of a 160 degree thermistat.
Q:
My engine overheats or runs hot, what could be wrong?
Loss of coolant (See related question/answer below)
Loss of system pressure (Pressure check)
Low coolant protection (Test solution and add coolant as required)
Belt tension too low (Set belt tension to spec)
Ignition timing retarded (Set timing to specifictions)
Timing retarded by malfunctioning ECM
Radiator fins obstructed (Clean away bugs, leaves, etc)
Cooling system passages (radiator, intake, cylinder heads, engine block) blocked
by rust or scale (Flush system - add fresh coolant)
Reservoir hose pinched or kinked, especially at radiator filler neck (Relieve kinks
by re-routing. Replace hose if necessary)
Lower radiator hose collapses (Check for hose spring position by squeezing lower end
of hose. Replace if necessary)
Radiator air flow in wrong direction (Incorrect fan blades - replace)
Inoperative fan clutch (Test and replace if necessary)
Stuck or obstructed thermistat (Replace thermistat, clear obstruction)
Q:
What style water pump does the L69 engine use?
The SS's L69 uses the long neck style small block chevy water pump.
Q:
What kind of radiator came stock on the SS?
The stock SS radiator is a 3 core style.
Q:
On the radiator, which is the return line to the transmission?
The top line is the return line back to the transmission.
Q:
What is the pressure rating on the stock SS radiator cap?
15 LB Closed System type (AC P/N RC27)
Q:
I'm loosing coolant somewhere. Where is it going?
Leaking radiator.
Radiator cap defective or filter neck distored.
Leaking coolant reservoir or hose.
Loose or damaged hoses or connections.
Water pump seal leaking (check weep hole on bottom of pump for evidence.
Replace if necessary.)
Water pump gasket leaking.
Improper cylinder head bolt torque. (check oil for milky sludge for evidence)
Cylinder head or gaskets leaking. (check oil for milky sludge for evidence)
Cylinder block or core plug leaking. (check oil for milky sludge for evidence)
