How many nuts are there on a 98 subaru Impreza outbacks starter?

Every 60,000 to 80,000 miles depending on your manufacturers reccomendations. The water pump is not normally changed untill you have a problem with it.

Sound like a short or high resistance caused by an in complete intermittanant connection. Did it buzZ while you were using the raising/lowering the window?

on the top of the engine block under the inlet mannifold

It is not as difficult to do for a determined and careful person who knows his/her ways.

1. Write done the code of your radio.
2. Disconnect the negative battery terminal.
3. Locate the positive (red) wire of the battery to where it ends, and remove it with a 12-mm socket and wrench. Remove the other thin positive wire attached to the solenoid.
4. Loosen and remove the starter-motor bolts with a 14-mm sockect and wrench. Then carefully take out the starter-motor.
5. Exchange the starter-motor for a rebuilt one at the dealer's or any competent autoparts store.
6. Reverse removal procedure for installation.

have you ever changed the differential oil

Im sure they will be diffrent,as the outback has more ground clearance ,you can tell for sure by looking at both and comparing differences

check for gas press regulator, broken gas line, or leaking injectors.

call wrecking yard they can tell you what years will fit or dealer! good luck!

The starter is separate from the soleniod; It could be a part called the bendix on the starter itself. If you can remove it, take it to a auto parts store- they will check it for free.

try jump starting it...you get more amps faster,see if that dosent get it started