Preliminary Overheating Diagnostic Inspection
- Does overheating occur while pulling a trailer?
- Is the vehicle equipped with an add-on, or aftermarket, air conditioning system? If so, was a heavy duty radiator installed?
- If overheating occurs after prolonged idle in gear with the A/C system operating, instruct the owner on the following driving techniques to avoid overheating:
- If overheating occurs after prolonged driving in slow city traffic, or traffic jams, instruct the owner on the following driving techniques to avoid overheating:
| • | Does the trailer weigh less than 454 kg (1,000 lb)? |
| • | Is the vehicle equipped with a heavy duty cooling package? |
| • | Idle the engine in Neutral (N) as much as possible. Increase the engine RPM in order to get the coolant flowing through the radiator. |
| • | If overheating is indicated by a hot lamp or the temperature gage, turn the A/C system off during extended idles of the engine. |
| • | Idle the engine in Neutral (N) as much as possible. Increase the engine RPM in order to get the coolant flowing through the radiator. |
| • | If overheating is indicated by a hot lamp or the temperature gage, turn the A/C system off during extended idles of the engine. |
If any of the above conditions apply, instruct the operator on driving techniques that would reduce the possibility of engine overheating.
Step | Action | Yes | No | ||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|
DEFINITION: Hot light on, hissing, rumble, steam, or power loss. | |||||||||||
1 |
Is the coolant to the proper level and the preliminary inspection been performed? | Go to Step 3 | Go to Step 2 | ||||||||
2 |
Notice: When adding coolant, use DEX-COOL® coolant. If silicated coolant is added to the system, premature engine, heater core or radiator corrosion may result. In addition, the engine coolant will require change sooner-at 50 000 km (30,000 mi) or 24 months. Are there any coolant leaks? | Go to Step 4 | Go to Step 5 | ||||||||
3 | Inspect for a loose accessory drive belt. Is the drive belt loose? | Go to Step 6 | Go to Step 7 | ||||||||
4 | Repair any coolant leaks as necessary. Does the engine still overheat? | Go to Step 3 | System OK | ||||||||
5 |
Are there any coolant leaks? | Go to Step 4 | Go to Step 3 | ||||||||
6 | Inspect the condition of the drive belt. Does the engine still overheat? | Go to Step 7 | System OK | ||||||||
7 | Inspect the condition of the radiator hoses. Are the hoses in good condition? | Go to Step 9 | Go to Step 8 | ||||||||
8 | Replace the hoses as necessary. Refer to Radiator Inlet Hose Replacement and Radiator Outlet Hose Replacement . Does the engine still overheat? | Go to Step 9 | System OK | ||||||||
9 | Inspect the temperature of the thermostat. Refer to Thermostat Diagnosis . Is the temperature level of the thermostat normal? | Go to Step 11 | Go to Step 10 | ||||||||
10 | Replace the thermostat. Refer to Engine Coolant Thermostat Replacement . Does the engine still overheat? | Go to Step 11 | System OK | ||||||||
11 | Inspect for a clogged radiator. Refer to Radiator Cleaning . Are the radiator coolant passages normal? | Go to Step 13 | Go to Step 12 | ||||||||
12 | Inspect and clean the radiator. Does the engine still overheat? | Go to Step 13 | System OK | ||||||||
13 | Inspect for a blockage in the engine block coolant passages. Are the engine block cooling passages normal? | Go to Step 14 | Go to Flushing | ||||||||
14 | Inspect if there are any combustion chamber gases leaking into the cooling system. Are there any bubbles present in the coolant? | Go to Step 15 | Go to Step 16 | ||||||||
15 | Repair as necessary. Does the engine still overheat? | Go to Step 16 | System OK | ||||||||
16 | Inspect the water pump for a low pumping volume. Is the pumping volume of the pump normal? | Go to Step 18 | Go to Step 17 | ||||||||
17 | Replace the water pump. Refer to Water Pump Replacement . Does the engine still overheat? | Go to Step 18 | System OK | ||||||||
18 | Inspect the radiator fan clutch. Is the fan clutch operating normally? | Go to Step 20 | Go to Step 19 | ||||||||
19 | Replace the fan clutch. Refer to Fan Clutch Replacement . Does the engine still overheat? | Go to Step 20 | System OK | ||||||||
20 | Other factors, such as the following, may be causing the engine to overheat:
Correct or repair as necessary. Does the engine still overheat? | -- | System OK | ||||||||
