4 replies to this topic

[incrediblerog]

evening all, did a quick search couldn't find anything really relevant to my prob/query, most topics are about the warning light being on!
ok so the story/problem... i did an oil change earlier today mainly because i was bored at work. i went through the normal routine.. warm up, run with flush (wynns), drain, replace plug with new washer, remove old filter, new filter on, fill up (20/50 mineral).. then when it came to the first run of the engine before topping up the oil, when i turned on the ignition the pressure light didnt come on!! i checked the connections, got the emery cloth out and cleaned them up and stuck another spadey thingy on the wire, tried again and nothing, managed to track down an assistant who told me that when i wiggled the wire the light flickered... so i'm pretty sure after earthing the wire and getting a solid light that the problem is the switch. now i know that during the oil change i didn't touch the switch or wiring to it at all, so question is why did it fail during the oil change??

any ideas, abuse or similar experiences welcomed.. oh yeah and it has crossed my mind that everything breaks eventually so maybe it was just the switches time!
cheers rog

[Dan]

They generally fail because they have something stuck in them. If you used an engine flush what this actually does is loosen up all the scale inside the oil system meaning that the oil is carrying all this gunge around with it briefly. Some of this can get into the switch and jam it. Just get a new one, once they get sticky they are unreliable. Try giving it a whack to fix it in the short term. I always use the high pressure 21 psi version. The standard item switches at 7 psi and by that point it's already a dead engine.

[incrediblerog]

They generally fail because they have something stuck in them. If you used an engine flush what this actually does is loosen up all the scale inside the oil system meaning that the oil is carrying all this gunge around with it briefly. Some of this can get into the switch and jam it. Just get a new one, once they get sticky they are unreliable. Try giving it a whack to fix it in the short term. I always use the high pressure 21 psi version. The standard item switches at 7 psi and by that point it's already a dead engine.

cheers dan, i'd thought this may be the case but having no idea what the switch looks like or how it works didn't want to jump to that conclusion! just out of interest, would the 21psi switch be suitable for a 70,000 miles, tired, old but still a contender of a 998 engine with a fresh sump of oil ?

[Dan]

Possibly not no, depends how good a contender it is really. You might find the warning comes on at idle a lot in that engine if you use the 21 psi version but it might not do. Hard to say really, don't suppose you have a guage you can check it with first?

[incrediblerog]

nope not pumbed in, i'm kinda thinking it might be a 21psi switch in there at the mo as it did like to flicker once nice and warm on idle, either way it's broke or worn so i'll just stick another one in there! thanks for the help mate!!