1991 doge dakota

Take the oil pan off, and it will be sitting there staring you in the face. Look at the replacement and see where the bolts are that hold the pump on. Remove them, take old pump out, put new one on. DO not overtighten the bolts. not a tough job, but very messy. Best to let the oil drain overnight after oil pan is removed. You will also need anew oil pan gasket

Make sure the drain bolt is tight and filter is tight first then look for your self and see If the value cover has oil around it if so it is the covers if not it could be your seals

Try cleaning the engine with degreaser and hose off the oil and muck. Let the engine dry out and then start the engine and look where the oil is leaking from.
From your description, the oil could be leaking from the tappet cover. May need a new gasket or the tappet cover bolts needs tightening.

no it is not worth that much, you can do it yourself for about 20-40 dollars (price of the gaskets)

follow these for better instructions go to www.autozone.com and register to become a member
this will give you access to their repair database there you can specify your car and get repair info.

Removal & Installation2.0L Spi Engine

1. Loosen the clamp and disconnect the engine air cleaner to valve cover hose from the valve cover.
2. Remove the two ignition wire separators from the valve cover. Position the spark plug wires aside.
3. Remove the three valve cover bolts and remove the valve cover and gasket.

To install:

CAUTION Do not use abrasive grinding discs to remove gasket material; only use manual scrapers. Do not scratch or gouge aluminum sealing surfaces or oil leaks may occur.

NOTE Do not use any sealer with a silicone-type gasket.

1. Install the three valve cover bolts and remove the valve cover and gasket.
2. Install the two ignition wire separators from the valve cover.
3. Tighten the clamp and disconnect the engine air cleaner to valve cover hose from the valve cover.

2.0L Zetec Engine

1. Disconnect the crankcase ventilation hose from the fitting on the valve cover.
2. Disconnect the wiring connector at the oil control solenoid.
3. Disconnect the speed control (if equipped) and the accelerator control cable.
4. Position aside the accelerator cable.
5. If equipped, disconnect the speed control cable from the bracket and position aside.
6. Remove the ignition wires from the spark plugs.
7. Remove the bolts and position the upper timing belt cover away from the valve cover.
8. Remove the valve cover.
9. Fully loosen the ten bolts.
10. Remove the valve cover and valve cover gasket.
11. Inspect the valve cover for damage. Install new cover as required.
    CAUTION Do not scratch or gouge aluminum sealing surfaces or oil leaks may occur.
    
12. Clean and inspect the sealing surfaces of the valve cover and the cylinder head. Both surfaces must be clean and flat.

To install:

1. The valve cover gasket and the valve cover must be installed and the bolts tightened to specification within four minutes of sealant application.
2. Apply a 0.1 inch (3mm) bead of silicone sealant in two places where the front camshaft bearing cap meets the cylinder head.
3. Install the valve cover.
4. Position the valve cover gasket.
5. Position the valve cover.
6. Tighten bolts in the sequence shown.
   
   

   Fig. The proper torque sequence for the 2.0L DOHC Zetec engine
   

7. Install the upper timing belt cover bolts.
8. Install the ignition wires.
9. Connect the oil control solenoid connector.
10. Connect the crankcase ventilation hose.
11. Connect the speed control (if equipped) and the accelerator control cables.
12. If equipped, connect the speed control cable to the bracket.

If you need further help, reach me via phone at https://www.6ya.com/expert/michael_17692f6169bfde50

go to a parts store and buy a valve cover gasket. remove valve cover, and old gasket. carefully clean all surfaces, install new gasket and do not over tighten the bolts when you put the valve cover back on.

Oil sending unit is it hard to replace?

most likely it is the valve cover gasket. it covers the valve train where there is alot of oil to lube the top of the motor. if the head gasket was leaking it may have more signs of running poorly. also having coolant leaks also. so i will have to say valve cover gasket. now usally you may have a oil burning smell with it depending on the area of the lek but not always.

the valve cover can easily be seen when the hood is open. it is right on the top and where it meets the clyinder head is where the gasket is and the leak can be seen.

if you have more question please ask.

The toyota previa uses a formed silicone gasket for the valve cover and the cover is held in place by metric shoulder bolts ( 10mm). The valve gasket leaks because you can't get enough preload on the bolts to re-seat the old gasket when it gets old and shrinks. The shoulder bolts only allow you to tighten the gasket enough to seat the shoulder on the bolt. If you continue to torque down the suspected bolts, you will snap the bolt off ( don't ask me how I know this ). You can either 1.)replace the old gasket with a new one or 2.) remove the existing bolts around the leak area and put in new metric bolts that do not have a shoulder. You may want to put in a small sleeve into the existing bolt hole but shorter than the thickness of the valve cover to account for the smaller diameter bolt. You can now torque down the bolt and get enough preload to seal the valve cover without removing the old gasket. Make sure you use a torque wrench ( in-lbs) or be very careful not to snap these small valve cover bolts.

The problem is over tightening.

If you over tighten your fastners you will sqeeze your gaskets too much and they WILL leak.

You can use black silicon sealant LIGHTLY but you don't really need it. If you have the V6...the torque on them nuts are only 80 in lbs each

If by head covers you mean valve covers this is an easy fix just install a new set of valve cover gaskets, as this is a fairly common problem ( valve cover gaskets ). Just unbolt the valve covers and remove them then scrape off the old gasket and install the new ones and bolt the covers back on. This is a pretty easy job and the gaskets are less than $ 25.00. If it is the oil pan gasket you will needto drain the oil and unbolt the oil pan and remove it then clean off the old gasket and install the new one.