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Oil cap pressure

Posted: Thu Nov 29, 2012 4:24 pm
by ebooksgti
Hi have just picked up a vitara everything seems like its running as it should over the hour drive home i opened the oil cap when the car was running when i got back and theres alot of pressure coming out of it is this normal ??

Re: Oil cap pressure

Posted: Thu Nov 29, 2012 8:09 pm
by dunnin21
Yeh you should have some pressure coming out while ticking over

Re: Oil cap pressure

Posted: Fri Nov 30, 2012 10:01 am
by ScottieJ
Is the Pcv valve hooked up and not stuck closed/ blocked? There should not be a lot of pressure.

Re: Oil cap pressure

Posted: Fri Nov 30, 2012 11:01 am
by ebooksgti
I will find out what that is and check as there is alot of pressure like its an extra exhaust

Re: Oil cap pressure

Posted: Fri Nov 30, 2012 8:48 pm
by Pugsley
Another possibility is that the cylinder bores and or the piston rings have excessive wear and are allowing exhaust gasses to pass in to the crankcase. If the crankcase venting system is not working 100% or the exhaust gas going into the crankcase is excessive and therefore is not fully being vented back in to the recirculation system, the crankcase pressure is relieved back up the bores past the rings and in to the rocker box.

Now it could be that the recirculation system on its own is malfunctioning or a combination of everything I've said. I think further investigation is required as to the condition of the valves and the bore/piston ring wear - a dry and wet compression test should reveal more. There will always be the potential for pressure in the crankcase of course due to the action of the pistons going up and down and the pumping effect on the underside of the pistons, but this catered for by the crankcase venting system.

Re: Oil cap pressure

Posted: Fri Nov 30, 2012 9:06 pm
by turbo-tom
it sounds like a the pcv valve to me so id say another vote on that ;)

Re: Oil cap pressure

Posted: Fri Nov 30, 2012 10:01 pm
by Christoff
Perfectly fine. I'd be worried if there wasnt any pressure there. If you open the cap while running good healthy oil pressure should spit out onto the rocker cover

Your looking directly onto the camshaft and rockers remember, all that needs healthy oil pressure

Iv opened the oil cap on plenty of new cars and had the oil spit everywhere.

Re: Oil cap pressure

Posted: Fri Nov 30, 2012 11:39 pm
by Pugsley
Quite agree with Cristoff but we appear to be talking about air pressure here rather than oil pressure - or have I missed the point?

Re: Oil cap pressure

Posted: Fri Nov 30, 2012 11:54 pm
by ScottieJ
I think we need to determine how much pressure we are talking about really, there should be some pressure there but excessive amounts.

Re: Oil cap pressure

Posted: Sat Dec 01, 2012 7:43 am
by ebooksgti
To me seems excessive its like end of exhaust pressure