Oil Light 1999 M Roadster.

**Drakman** · 08-12-2022, 09:32 AM

Hi Guys and Girls,

I have a 1999 M roadster with 98,000 klm's on the odometer, that i purchased about 18 months ago.

The car doesn't get used much, I sometimes have to charge the battery to start it. I have found that the oil light comes on after approximately 10 klm's. I stop the car turn the ignition off and the oil light stays on, quite brightly, for maybe 30 seconds I can then restart the car and drive a further 10 klm's before it comes on again. The oil and filter are fresh, I have replaced the oil pressure sender unit and the constant oil pressure valve (up behind the exhaust manfolds) This kind of feels like an electrical issue but i have no idea where to go next. Has anyone here had this problem or perhaps know of a solution?

Thanks
Dave

**s8ilver** · 08-12-2022, 12:28 PM

What color is the light?

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**Randy Forbes** · 08-12-2022, 12:33 PM

First thing I'd do is add a mechanical oil pressure gauge.

I'm guessing that you have the S50B32 engine (6-individual throttle bodies) which most of us on this forum are unfamiliar with__from a hands-on point of view, we all KNOW what it is (and wish we had one...). IF it has the oil level sensor on the sump, then that is likely to be causing your issue, as it's know to fail on the S54 engines that we DO have in the US.

Get a mechanical gauge hooked up__even if just temporarily, and please report back.

**Drakman** · 08-13-2022, 04:58 AM

Hi S8ilver and Randy, The light is bright red. Yes Randy i have the S50 B32 engine, is the oil level sensor the black sensor thing in the bottom of the oil pan next to the round plate that holds the oil pump filter screen? I have been thinking about an external oil pressure gauge test, do you know where to attach the gauge to the engine is there an outlet on the oil filter area? I don't think the engine actually has low oil pressure but I would love to know for sure.

Thanks guys for the info, I will replace the oil level sensor and let you know if it fixes the problem.

**Randy Forbes** · 08-15-2022, 12:35 PM

Originally Posted by Drakman

Hi S8ilver and Randy, The light is bright red. Yes Randy i have the S50 B32 engine, is the oil level sensor the black sensor thing in the bottom of the oil pan next to the round plate that holds the oil pump filter screen? I have been thinking about an external oil pressure gauge test, do you know where to attach the gauge to the engine is there an outlet on the oil filter area? I don't think the engine actually has low oil pressure but I would love to know for sure.

Thanks guys for the info, I will replace the oil level sensor and let you know if it fixes the problem.

You can buy an adapter* that lets you "T" into the same (M12x1.50) port that the o/p sender is mounted at.

(S52 engine shown, but same filter housing__we even call it the "Euro" one; std. on S54 here in the US)

* I used to make them, but they can now be purchased from Clown Shoe Motorsports https://www.clown-shoe.com/home

** The example seen here actually has a "modified" Banjo-Bolt for the VANOS oil feed line (M12 threads x M14 body) that I drilled/tapped the end of for the OE pressure sender, but any combination that leaves the original devices intact plus a take-off point for an aftermarket (mechanical or electric) gauge will work.