Engine Lifters connected to the Headlight Switch? - 986 Forum - The Community for Porsche Boxster & Cayman Owners

Hi, It's been a while since I actually posted here, but I was hoping to get the help and advice I greatly appreciated in the past. I have a 2004 S and I encountered a strange situation yesterday. I was out to buy some gas to top off the tank for the winter storage. The engine was warm, the Boxster was performing extremely well and dusk was approaching. I turned on the headlights, the oil pressure warning light popped on and the lifters started hammering. Pulled off the side of the road, turned off the engine and lights, waited a few seconds and restarted the engine. No warning light, no lifter noise! Turned on the headlights again and yhe warning light and lifter noise started again. I shut off the engine, waited and restarted. Turned on the parking lights and fog lights and had no issues. Drove it home and parked the car in the garage. Just for information's sake, I do have a set of Nine8Six's BiXenon projectors installed (Not blaming them) Could the head light switch cause a problem with the delivery of oil to the engine? Thanks in advance for your help.

Wow that's a strange one. Maybe a bad headlight switch is causing a big power surge that the alternator has to handle quickly? Is there an electrical regulator for oil pressure? My headlight switch went a couple of months ago, and my Nine8Six projector lights wouldn't fire up, they were sending out short morse code-like quick blinks at less than full power, but the parking lights and fog lights worked fine. No oil pressure issues though. Hope one of the experts here can chime in for you.

There should not be any connections between the headlight switch and the oiling system or lifters.

How do you know it’s lifter noise? Turning on Headlamps would create a load on your alternator. Maybe alternator is on the way out (bearing noise).

What Jeff said. Most likely you have an electrical problem effecting your ECU. Either the light circuit is introducing voltage somewhere in the harness or it lost its ground and pulling it from somewhere corrupting the sensor signals going to your ECU. That's probably why your oil light came on, and the noise you hear is probably the engine out of tune. (wrong spark timing, wrong fuel mixture, etc.) If your ECU gets garbage in it'll go haywire, which is probably what's happening. I'd start by checking your lighting circuit. Check the grounds, etc.

I had a similar problem. Low oil pressure light came on while driving when I turned on bi-xenons. Pulled over and shut down. Restarted and it was gone. It happened intermittently for a while until on a long drive the headlights took a long time to come on. I replaced the headlight switch and it's been good ever since. On most modern cars the headlight switch runs to a relay to turn the lights on. On these cars, I'm pretty sure the full amperage for the headlights runs through the switch. I'm guessing that a failing switch can drop the voltage below tolerance. In the '03 and '04 the Variocam Plus may be unhappy with the variation in voltage.

Thank you all for your input, it's much appreciated. I'm going to get the battery tested to see if is part of the problem. It is an easier replacement than the headlight switch. (I am not a contortionist). Dghii, I don't think it's the alternator, since the condition is not happening all the time. 78F350, thanks for the info on a path forward.

The headlight switch is a lot easier to change than the ignition switch! Just get a tiny screwdriver to put in the little cutout slot in the bezel under the bottom side and that outer bezel will slide right off! That was the hardest thing for me to figure out, it wasn't in the videos or writeups I found on the web.

Thank you PaulE