Dodge Nitro. Manual - part 48

If the leakage occurs at the crankshaft rear oil seal area:

1. Disconnect the battery.  

2. Raise the vehicle.  

3. Remove torque converter or clutch housing cover and inspect rear of block for evidence of oil. Use a 

black light to check for the oil leak: 



Circular spray pattern generally indicates seal leakage or crankshaft damage.  



Where leakage tends to run straight down, possible causes are a porous block, oil galley pipe plugs, 
oil filter runoff, and main bearing cap to cylinder block mating surfaces. See Engine, for proper 
repair procedures of these items.  

4. If no leaks are detected, pressurize the crankcase as described in AIR LEAK DETECTION TEST 

METHOD. 

5. If the leak is not detected, very slowly turn the crankshaft and watch for leakage. If a leak is detected 

between the crankshaft and seal while slowly turning the crankshaft, it is possible the crankshaft seal 
surface is damaged. The seal area on the crankshaft could have minor nicks or scratches that can be 
polished out with emery cloth. 

6. For bubbles that remain steady with shaft rotation, no further inspection can be done until disassembled. 

See ENGINE LUBRICATION DIAGNOSTIC TABLE under the Oil Leak row, for components 
inspections on possible causes and corrections.  

7. After the oil leak root cause and appropriate corrective action have been identified. See REMOVAL.  

CHECKING ENGINE OIL PRESSURE 

CAUTION: Do not exceed 20.6 kPa (3 psi).

CAUTION: Use extreme caution when crankshaft polishing is necessary to 

remove minor nicks or scratches. The crankshaft seal flange is 
specially machined to complement the function of the rear oil seal.

 

2007 Dodge Nitro R/T 

2007 ENGINE 3.7L - Service Information - Nitro

  

Fig. 139: Locating Oil Pressure Sending Unit, Connector & Oil Filter 
Courtesy of CHRYSLER LLC 

1. Remove oil pressure sending unit. See Fig. 139 (2) and install gauge assembly C-3292.  

2. Run engine until thermostat opens.  

3. Oil Pressure: 

Curb Idle - 25 kPa (4 psi) minimum 

1 - BELT
2 - OIL PRESSURE SENSOR
3 - OIL FILTER
4 - ELEC. CONNECTOR

 

2007 Dodge Nitro R/T 

2007 ENGINE 3.7L - Service Information - Nitro

  

3000 rpm - 170 - 758 kPa (25 - 110 psi)  

4. If oil pressure is 0 at idle, shut off engine. Check for a clogged oil pick-up screen or a pressure relief 

valve stuck open.  

OIL 

STANDARD PROCEDURE 

ENGINE OIL SERVICE 

Fig. 140: Identifying Engine Oil & Transmission Dipsticks & Engine Oil Fill Cap 
Courtesy of CHRYSLER LLC 

1 - TRANSMISSION DIPSTICK

 

2007 Dodge Nitro R/T 

2007 ENGINE 3.7L - Service Information - Nitro

  

The engine oil level indicator. See Fig. 140 (1) is located at the right rear of the engine on the 3.7L/4.7L 
engines. 

CRANKCASE OIL LEVEL INSPECTION 

Inspect engine oil level approximately every 800 kilometers (500 miles). Unless the engine has exhibited loss of 
oil pressure, run the engine for about five minutes before checking oil level. Checking engine oil level on a cold 
engine is not accurate. 

To ensure proper lubrication of an engine, the engine oil must be maintained at an acceptable level. The 
acceptable levels are indicated between the ADD and SAFE marks on the engine oil dipstick. 

1. Position vehicle on level surface.  

2. With engine OFF, allow approximately ten minutes for oil to settle to bottom of crankcase, remove 

engine oil dipstick.  

3. Wipe dipstick clean.  

4. Install dipstick and verify it is seated in the tube.  

5. Remove dipstick, with handle held above the tip, take oil level reading.  

6. Add oil only if level is below the ADD mark on dipstick.  

ENGINE OIL CHANGE 

Change engine oil at mileage and time intervals described in Maintenance Schedules. 

Run engine until achieving normal operating temperature. 

1. Position the vehicle on a level surface and turn engine off.  

2. Hoist and support vehicle on safety stands.  

3. Remove oil fill cap.  

4. Place a suitable drain pan under crankcase drain.  

5. Remove drain plug from crankcase and allow oil to drain into pan. Inspect drain plug threads for 

stretching or other damage. Replace drain plug if damaged.  

6. Install drain plug in crankcase.  

7. Lower vehicle and fill crankcase with specified type and amount of engine oil described in this article.  

8. Install oil fill cap.  

9. Start engine and inspect for leaks.  

2 - ENGINE OIL DIPSTICK
3 - ENGINE OIL FILL CAP

CAUTION: Do not overfill crankcase with engine oil, pressure loss or oil foaming can 

result.

 

2007 Dodge Nitro R/T 

2007 ENGINE 3.7L - Service Information - Nitro