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Discussion Starter #1
Did a drain and refill on the radiator last night. Opened the bleed screw until I saw coolant. Let the motor run (I have a lisle funnel) until the tstat opened and it pretty much stopped burping. The heat took a bit longer than usual to get hot. What’s got me a bit worried is that once I press the accelerator, the heat gets scolding hot. Once I let go, it goes back to “very warm/hot”. Is this normal or indicative of an air bubble? I’ve got through about 3-4 warm-up/cool down cycles and the level of coolant in the overflow hasn’t changed.
I can try opening the bleed screw again but wouldn’t that not do anything if the air bubble is possibly in the heater core? If I should re-open the bleeder, what is the procedure? (radiator cap off, drain the overflow, etc). Thanks in advance.

2010 5.7 XK Sport

25 Posts

1. Close radiator draincock. Hand tighten only.
2. Install engine block drain plugs, if removed. Coat the threads with MoparT Thread Sealant with Teflon.
WARNING: When installing drain hose to air bleed valve, route hose away from accessory drive belts,
accessory drive pulleys, and electric cooling fan motors.
NOTE: It may be necessary to install a bleed fitting on the 5.7L engine.
3. Attach a 1.5-2m(4-6ft.) long 6 mm (1/4 inch.) ID clear hose to bleeder fitting
² Plug Location (5.7L): Located on the front of the water outlet housing at the front of engine.
4. Route hose away from the accessory drive belt, drive pulleys and electric cooling fan. Place the other end of
hose into a clean container. The hose will prevent coolant from contacting the accessory drive belt when bleed-
ing the system during the refilling operation.
NOTE: It is imperative that the cooling system air bleed valve be opened before any coolant is added to the
cooling system. Failure to open the bleed valve first will result in an incomplete fill of the system.
5. 5.7L ENGINE - Install a threaded and barbed fitting (1/4 - 18 npt) into water pump housing.
6. Attach Special Tool 8195 (1), Filling Aid Funnel to
pressure bottle filler neck.
7. Using hose pinch-off pliers, pinch overflow hose (3)
that connects between the two chambers of the
coolant bottle (2).
8. Open bleed fitting.
CAUTION: Do not mix coolants. If coolant is used
other than specified, a reduction in corrosion protection
will occur.
9. Pour the antifreeze mixture (Refer to LUBRICATION
into the larger section of Filling Aid
Funnel (the smaller section of funnel is to allow air
to escape). For system capacity, (Refer to 7 -
10. Slowly fill the cooling system until a steady stream of coolant flows from the hose attached to the bleed valve.
11. Close the bleed valve and continue filling system to the top of the Special Tool 8195 (1).
12. Remove pinch-off pliers from overflow hose.
13. Allow the coolant in Filling Funnel to drain into overflow chamber of the pressure bottle.
14. Remove Tool 8195 (1). Install cap on coolant pressure bottle.
15. Remove hose from bleed valve.
16. 5.7L ENGINE - Install fitting into thermostat housing. Coat the threads with MoparT Thread Sealant with Teflon.
17. Start engine and run at 1500 - 2000 RPM for 30 minutes.
NOTE: The engine cooling system will push any remaining air into the coolant bottle within about an hour
of normal driving. As a result, a drop in coolant level in the pressure bottle may occur. If the engine cooling
system overheats and pushes coolant into the overflow side of the coolant bottle, this coolant will be
sucked back into the cooling system ONLY IF THE PRESSURE CAP IS LEFT ON THE BOTTLE. Removing
the pressure cap breaks the vacuum path between the two bottle sections and the coolant will not return to
cooling system.

18. Shut off engine allow it to cool down for 30 minutes. This permits coolant to be drawn into the pressure chamber.
19. With engine COLD, observe coolant level in pressure chamber. Coolant level should be within MIN and MAX
marks. Adjust coolant level as necessary.

Premium Member
674 Posts
Sounds like an air bubble in there. Just check under the radiator cap when cool and top off - it may not be able to pull coolant from the overflow tank if air in system. If the engine is not overheating and just the problem with the heater - it will work itself out over time.
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