I picked up a '91 RS a few weeks ago, and it has an LO5 swapped in it, on the oil pan is a level sesor above the drain plug...appears to be metric thread...seems to fall inbetween 16 and 18 TPI via my thread gauge.

Anyone know what kinda metric bolt size I need to eliminate it?

Thing is, it a plastic threaded sensor...okay...

Fun part is the drain plug is stripped out and will not remove from its place...so in order to draing the oil I had to remove the sensor, drain a few quarts, the suck out from the sensor hole.

On putting back in the sensor, it wants to cross thread badly..after some filing, I was able to get it back in fine...but this will most likely happen next time and I'd rather find something metal (bolt/daringplug, etc) to use.

Naw, don't want to drop the pan to fix it right just yet

 

Does it look like this?

 

Pretty similar..that one looks like it's metal...and has less threads...but might just be a design difference though.

Any idea of what could be used as a plug?

Thanks

 

That particular oil level sensor is from an LT1, and is a 20mm x 1.5 thread. Your LO5 may be the same, or not.

My first choice would be to use a welding clamp (a.k.a. Vise Grip) and pull on the drain plug as you turn it counter-clockwise to help pick up the threads and remove the plug. Abandon the metric drain plug. Chase the threads with a ½-20 tap, then install a NEW oil drain plug, oversized if necessary. Keep plug torque below 8-12 Ft/Lb and it should work well.

 

Ya, tried all the tricks, have the car over my Dads pit....even made a slight "wedged, pickel fork thing", tried tapping it inbetween the pan and plug while backing out...no go.

Was thinking about filling it back up with oil, taking it to Jiffy Lube and saying "WTF did you do to my car?"

What's funny is it feels like it's actually spinning the innards, like the nut part on the inside isn't holding.

I'll see if the parts house has the LT1 sensor in stock, if it's the same then I'm in business,

Thanks again for information well done.

 

If the existing drain bolt is not leaking, you could drill a small hole in a new location, punch the pan further with a tapered punch (to roll material backward into the pan), then drill/tap the new hole for an additional plug. There are several locations that can be used as drain plugs.

Oddly, some "luxury" cars don't even have drain plugs any more. You could have two.