VW Vortex - Volkswagen Forum banner
1 - 1 of 1 Posts

2,692 Posts
Re: Oil Light in '99 Passat 1.8T (VW Newbie1)

The sending unit could be bad, or oil that is too thin was put in.
Overfilling the oil can cause it to foam up, causing problems.
Over filling can blow seals out, get into and ruin the catalytic converters, and is a bad idea.
Oil pressure problems are likely very rare.
A mechanical problem would have the motor knocking badly, although its possible to have a stuck bypass valve in the pump I suppose.
You can measure the oil pressure with a gauge, not sure how hard that is on the 1.8t, you would screw a gauge in place of the oil
pressure switch that activates the alarm.
Since you might replace the switch anyway, checking the actual
pressure would be a good idea, and should be easy to do.
If the pressure IS low, could be a pump problem (stuck open bypass).
Not sure if you can get at the bypass valve without a lot of effort.
Some engines have easy ways to get at it.
2003 GLX
1 - 1 of 1 Posts