History:

The water pump went out and the engine overheated. Next the oil light warning system came on, then the starter went out.

Water pump replaced. Oil warning system still activated. No check engine light on. Oil level and appearance fine. Spark plugs look fine. Starter replaced (twice). Second starter failed. Runs rough and smokes on acceleration/deceleration.

Questions:

What could have been damaged by the overheating that is causing the oil warning system to activate?

Why do starters keep failing?

What other diagnostics should I be doing?

Thank you so much for your help. I need to decide if this is worth repairing or if I need another daily driver.

 

All it says is 1997 Jetta which engine size?

Did the water pump replacement cure the overheating?

Are you replacing the starter motor which another second hand one?

You need to fit an oil pressure gauge and measure the oil pressure it should be 2.0 bar (30 psi) at 2000 rpm. If the pressure is ok replace the oil pressure switch.

You need to get your motor scanned (preferably with VAG-COM\VCDS) for any error codes logged in the ecu and post them, that will save a lot of guessing.