Imperial Home Page -> Repair -> Cooling System -> Checklist
1) Clean the engine and radiator. Good degreaser followed by a pressure wash....watch out for the radiator fins, carburetor, etc.
2) Check all of your radiator hoses. Sometimes, lower Radiator hose collapses during high RPM operation due to no or rotted away interior spring in hose.
3) Flush/Fill/Purge entire cooling system.
4) Check how hot your coolant gets. With a COLD engine, remove the radiator cap. Start and let the engine heat up. Stick a candy thermometer in the coolant and see what it reads. When the temperature stabilizes, you'll see what the actual coolant temperature is, and you can then decide if you have a problem or simply a bad indicator.
5) Check to make sure fan blade is mounted correctly and not backwards, ruining efficiency of fan/air energy transfer.
6) Check to make sure that air is going through the radiator, and not finding its way around, under or over the radiator due to missing, bent or incorrectly installed shrouding.
7) Check to make sure you have no transmission slippage, causing the transmission cooler to transfer excessive heat to coolant. The transmission cooler in the bottom of the transmission can put a lot of heat into the system and may need to be replaced.
8) Check EGR valve for proper operation.
9) Make sure you do not have a lean mixture or retarded spark timing.
10) No bugs in the AC condenser or radiator fins.
11) Check exhaust manifold butterfly valve for proper operation.
12) Check heat riser for proper operation and it is not stuck in the closed position.
13) Install aftermarket temperature gauge temporarily (or perhaps permanently...).
14) Replace thermostat with lower rated one.
15) Check timing per factory service manual specifications.
16) Check water pump and their belts for correct tightness.
17) Make sure you do not have crud in your block breaking loose and depositing on top of radiator core. (Get a dentist's mirror and a powerful little light and take a look at the top of the tubes through the cap or upper hose opening). If this is the problem, get a coolant filter and install it in the upper hose until it stays clear. You may also have to knock out the core plugs in the block and dig out the crud. Easy way to see if you need to do this is to open the block drains on both sides of the block and see if anything comes out the holes without poking them with a sharp stick first. This problem can sometimes can be solved by a complete flush but often requires pulling the freeze plugs and rodding out the water galleries then flushing.
18) Next time you are running hot, check the temperature differential between the upper and lower hoses between the radiator and the engine (watch out for that fan!!). There should be a very substantial difference - if you can beg, borrow or steal a surface temperature meter, see if you can measure this. With a warm engine, idling, on a healthy system, the upper hose should be a little hotter than your thermostat setting ( a "180" is fine, by the way) and the lower hose should be around 140 or cooler. If there is little difference, the radiator is not cooling well enough. If there is way too much difference, (like the lower hose is almost cool), the water is not circulating well, probably due to a slipping impeller on your water pump, or a collapsed lower hose (which you can check for visually - you did make sure the coil spring was in there, right?). We're assuming here that the belts are not slipping, and that the fan is the correct one and properly positioned and shrouded.
This page last updated September 23, 2001. Send us your feedback, and come join the Imperial Mailing List - Online Car Club