Replace oil pump

Very low or no oil pressure reading does not necessarily mean the oil pump is not working and if you replaced the oil pump because of low oil pressure does not mean the original pump had necessarily failed. It may have but it may not have. Oil pressure is not created by the oil pump but by the resistance to oil flow. If you have very low resistance to flow you will get very low oil pressure no matter how well the oil pump is pumping. If you have a very worn engine, especially the bottom end main bearings and conrod bearings, tolerances increase very significantly, there is little resistance to flow and you will achieve very low oil pressure and metal parts will touch. Oil flow to the upper part of the engine may also suffer. If your engine is gummed up with oil sludge due to too few oil changes some oil passages may be blocked as well.

You have to remove the engine front cover (over timing chain) and remove the oil pan to get the oil pump in and out. You don't have to remove the heads, however.

Removal & Installation

4.8L, 5.3L, 6.0L & 6.2L Engines






Fig. Exploded view of the oil pump mounting-4.8L, 5.3L, 6.0L and 6.2L engines


Fig. Oil pump disassembly-4.8L, 5.3L, 6.0L and 6.2L engines

1. Remove or disconnect the following:
   
   
   NOTE
   
   Do not allow dirt or debris to enter the oil pump assembly, cap ends as necessary.
   
   
   
   
   NOTE
   
   The internal parts of the oil pump assembly are not serviced separately (excluding the spring). If the oil pump components are worn or damaged, replace the oil pump as an assembly. Do not attempt to repair the wire mesh portion of the pump and screen assembly.
   
   
   
   
   
   Engine front cover Oil pan Oil pump screen bolt and nuts Oil pump screen with O-ring seal. O-ring seal from the pump screen. Discard the O-ring seal. Remaining crankshaft oil deflector nuts. Crankshaft oil deflector Oil pump bolts
   
   
   
   
   
   
   
   Oil pump To install:
   
   
   
   
   NOTE
   
   Inspect the oil pump and engine block oil gallery passages. These surfaces must be clear and free of debris or restrictions.
   
   
   
   
   
   
   1. Align the splined surfaces of the crankshaft sprocket and the oil pump drive gear and install the oil pump. Install the oil pump onto the crankshaft sprocket until the pump housing contacts the face of the engine block.
   
   
   
   2. Install or connect the following:
      
      
      NOTE
      
      Lubricate a NEW oil pump screen O-ring seal with clean engine oil.
      
      
      
      
      NOTE
      
      Push the oil pump screen tube completely into the oil pump prior to tightening the bolt. Do not allow the bolt to pull the tube into the pump.
      
      
      
      
      
      Oil pump bolts. Tighten the oil pump bolts to 18 ft. lbs. (25 Nm). Crankshaft oil deflector
      
      
      
      
      
      
      
      NEW O-ring seal onto the oil pump screen
      
      
      
      
   
   
   
   3. Align the oil pump screen mounting brackets with the correct crankshaft bearing cap studs.
   
   
   
   4. Install or connect the following:
      
      
      
      
      Oil pump screen Oil pump screen bolt and the deflector nuts. Tighten the bolt to 106 inch lbs. (12 Nm) and the nuts to 18 ft. lbs. (25 Nm). Oil pan Engine front cover
      
      
      
   
   
   
   
   
   
   

pull of the timing cover to reveal the chains turn the engine over until all the timing marks line up on tdc. From there on do not turn anything when you remove any chains and it will all go back together ok.

the 2.3 and 3.1 engines need to drop oil pan.for the 3.3 engine you have to remove timing chain cover.you have to remove oil filter adapter the pressure regulator valve and the valve spring.then remove oil pump cover to oil pump screws remove cover remove oil pump gears.when installing another new oil pump lubricate the oil pump gears with clean engine oil pack the pump cavity with petroleum jelly.torque oil pan cover screws to 97 inch lbs which would be 11 ft lbs torque.oil filter adapter plate 24 ft lbs.

check temperature of engine consider oil cooler if you drive it hard Re: Jeff

5.2L and 5.9L Engines
It is necessary to remove the oil pan, and to remove the oil pump from the rear main bearing cap to service the oil pump.

1. Drain the engine oil and remove the oil pan.
2. Remove the oil pump mounting bolts and remove the oil pump from the rear main bearing cap.

To install:

1. Install the pump and tighten the cover bolts to 95 inch lbs. (11 Nm).
2. Prime the oil pump before installation by filling the rotor cavity with engine oil. Install the oil pump on the engine and tighten attaching bolts to 30 ft. lbs. (41 Nm).
3. Install the oil pan.
4. Fill the engine with the proper grade motor oil. Start the engine and check for leaks.

No. You have to lift the engine. The distributor has a gear on it. this is what drives the oil pump. Most times 99% the bearings are worn out causing low oil pressure. I have replaced oil pumps, not because they were bad, but because someone wanted a high pressure pump. The first thing I would do if I suspected oil pressure problems is put a mechanical guage on the engine. If the oil pressure is normal then all you need to do is replace the oil sending unit. Of course if you knocking in the lower engine, then it would be bad bearings. Forget the pump. you need to replace the engine

Why do you want to replace the oil pump? I am asking this question for good reason. Engines that have worn bearings will have low oil pressure, and replacing the pump will not solve this problem. If you are replacing the pump because of low pressure, then you really need to consider correcting the cause of the low pressure. To replace the pump, you need to remove the oil pan from the bottom of the engine, which will likely involve raising the engine. Once the oil pan is off, you can readily remove and replace the oil pump.

REMOVAL & INSTALLATION

Gasoline Engines
See Figures 1 and 2



Fig. Fig. 1: Exploded view of the oil pump used on 2.0L and 2.3L gasoline engines



Fig. Fig. 2: Exploded view of the oil pump used on the 4.0L engine-2.8L and 2.9L engines are similar

1. Follow the service procedures under Oil Pan Removal and remove the oil pan assembly.
2. Remove the oil pump retainer bolts and remove the oil pump.

To install:

1. Prime the oil pump with clean engine oil by filling either the inlet or outlet port with clean engine oil.
2. Rotate the pump shaft to distribute the oil within the pump body. Install the pump and tighten the mounting bolts to 14-21 ft. lbs. on 2.0L and 2.3L engines; 6-10 ft. lbs. on 2.8L and 2.9L engines or 13-15 ft. lbs. on 4.0L engines.

Do not force the oil pump if it does not seat readily. The oil pump driveshaft may be misaligned with the distributor shaft assembly. To align, rotate the intermediate driveshaft into a new position.

1. Install the oil pan as previously described. The oil pumps are not serviceable. If defective, they must be replaced.

Remember rated this.

Remove the engine front cover then drain the engine oil and take out the oil pan. It is under the engine and looks like the bottom of the motor.
Unscrew the oil pump mounting bolts with a wrench and proceed to remove the oil pump itself by pulling it down and out of the engine. Avoid getting any contaminants into the oil pump assembly while removing.
Add fresh oil to the new pump to prime it. Check the alignment on the new oil pump drive with the crankshaft/intermediate crankshaft timing.

Step 2 Install the new pump carefully, rotating it back and forth a little to make sure it has full surface contact between the pump and the engine block.

Step 3 Hold the pump in its sealed position and put in the pump mounting bolts, tightening them to 15 ft-lb.

Step 4 Put the engine oil pan back in and refill the crankcase. Start the engine and check for leaks on the parts you replaced