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Dry dipstick VW but not T25
Posted: 08 Jan 2016, 15:52
by itchyfeet
On the car I sometimes pull the dipstick and it's dry, when it happens it takes a few seconds of panic before I remember to put it back, pull it again and then it has the oil to the right level
How on earth if it's in the oil can it come out dry
VW Polo 1.4 petrol 2007, It just happened, it has just had an hours run home and rested for an hour too, so I wonder if being very hot when parked has an affect?
Re: Dry dipstick VW but not T25
Posted: 08 Jan 2016, 15:59
by lloydy
Could it just take a while for the oil to drain back to the sump?
Re: Dry dipstick VW but not T25
Posted: 08 Jan 2016, 16:03
by CJH
Maybe the dipstick tube goes all the way down beyond the end of the dipstick to below the level of the oil, and the dipstick makes an airtight seal at the top of the tube. So when the engine is running the sump level drops, so the tube is then filled with air, which prevents the oil rising back into the tube as it settles back into the sump.
If that's what it's doing, then the next time you want to check it you could just 'crack' the seal between the dipstick and the tube and see if the oil level rises.
Re: Dry dipstick VW but not T25
Posted: 08 Jan 2016, 16:32
by itchyfeet
CJH wrote:Maybe the dipstick tube goes all the way down beyond the end of the dipstick to below the level of the oil, and the dipstick makes an airtight seal at the top of the tube. So when the engine is running the sump level drops, so the tube is then filled with air, which prevents the oil rising back into the tube as it settles back into the sump.
If that's what it's doing, then the next time you want to check it you could just 'crack' the seal between the dipstick and the tube and see if the oil level rises.
I think you have it there^^^
trouble is it doesn't happen every time so hard to test
Re: Dry dipstick VW but not T25
Posted: 08 Jan 2016, 16:34
by CJH
If this is what it's doing, then pushing the dipstick firmly in before running the engine, to ensure an airtight seal at the top, should make it happen more reliably.
Re: Dry dipstick VW but not T25
Posted: 08 Jan 2016, 16:35
by itchyfeet
lloydy wrote:Could it just take a while for the oil to drain back to the sump?
it had an hour
itchyfeet wrote:, it has just had an hours run home and rested for an hour too
Re: Dry dipstick VW but not T25
Posted: 08 Jan 2016, 16:36
by itchyfeet
CJH wrote:If this is what it's doing, then pushing the dipstick firmly in before running the engine, to ensure an airtight seal at the top, should make it happen more reliably.
Yes maybe a smear of oil too to make sure it seals.
Re: Dry dipstick VW but not T25
Posted: 08 Jan 2016, 23:00
by Smosh
itchyfeet wrote:CJH wrote:If this is what it's doing, then pushing the dipstick firmly in before running the engine, to ensure an airtight seal at the top, should make it happen more reliably.
Yes maybe a smear of oil too to make sure it seals.
Id prob use some gasket seal or silicone...