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Forcing Oil Pressure By Disconnecting Cas?

mosquitocoils

By mosquitocoils,
in General Maintenance

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mosquitocoils Veteran

mosquitocoils

Posted
Posted

Hi all, hopefully I'll get an answer from you knowledagble lot here.

Basically my car has been sitting for a few weeks, unstarted. Picking up a new battery for one, and I will be getting some fresh oil to put in soon enough, but for the first start up should i disconnect by CAS and try cranking to build up oil pressure to get my bearings lubricated? And secondly, can someone tell me how/why this works?

Will the car start at all with the CAS unplugged? Or will it just keep trying but never get there?

Thanks guys

mad082 Grand Master

mad082

Posted
Posted

to be brutally honest it probably won't be required. if you do want to get the oil circulating a bit first, then yes, unplugging the CAS and turning the car over for about 30 seconds will do the job.

unplugging the CAS will stop the injectors firing and the spark plugs sparking.

blind_elk Grand Master

blind_elk

Posted
Posted

Ordinarily you would only do the oil-pressure-build-up on a brand new built engine. The last thing you want is for your brand new engine to fire, and have absolutely no oil flowing and lubricating your brand new bearings. So you crank it over so you can see that oil pressure is happening.

A few weeks for a previously working engine wouldn't be such a problem, and you would probably have oil pressure by the time the engine actually fires.

Beer Baron Grand Master

Beer Baron

Posted
Posted

I wouldn't bother of a few weeks. even a month or two. after 6 months it's probably a good idea. but yeah for 2 weeks don't bother. it will come up to pressure pretty quick.

mosquitocoils Veteran

mosquitocoils

Posted
  • Author
Posted

Thanks for the quick replies, top stuff guys.

I have noisy lifters if I don't drive the car for say, a week normally. So I was thinking it could be helpful seeing as it's probably around 6 weeks without being started? Or not to bother? If taking an extra 7 seconds to unplug the CAS could potentially save me a lot of hassle, I'd rather do it I guess.

Should I drop and replace the oil before I fire it up, or after it's warm and been circulating?

JonnoHR31 Grand Master

JonnoHR31

Posted
Posted

nope, drop it before you start it as all the oil will already be sitting at the bottom of the sump.

dont bother cranking it, most of the time this isnt enought to get any oil pressure in the head, fire it up and it should build pressure within a second or so

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