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oldtech

GT Blocked crankcase breather affecting dipstick levels?

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oldtech

My dipstick levels have always been up and down for the past 4 years - can a blocked crankcase breather cause this? Always checked when car is level.

 

Also, I've always run the dipstick to show the hatched area upwards when pulled out, but when inserted 'upside-down' the level shows halfway down in comparison - a big difference to get right: what's the correct orientation?

 

(I keep it topped up but have recently been running a little lower in case I'm unknowingly overfilling - but then it runs noisy. It's currently about 5-7mm over the hatched area and runs fine - might be overfilled but presumed inaccurate..)

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steveo3002

easy way to suss this...drain the oil and replace the filter , measure in exaclty what the haynes says and then see if the dipstick reads full

 

never had an issue with mine ...reads consistent both sides of the stick   , warm or cold , just make sure its stood on flat ground ...some of the later cars have more of a wire rod vs the flat dipstick , could see if you can grab one to try ( make sure its identical length)

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steveo3002

blocked crank breather would = lots of oil leaks from gaskets and if you remove the oil cap when running you would feel considerable pressure /force from the opening , a little is to be expected 

 

would it cause funny oil readings...no i doubt it 

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oldtech

My gaskets are leaking from somewhere as the cambelt always has a thin film of oil toward the engine edge which I periodically clean off. The rocker gasket is new.

 

The dipstick ring-pull is yellow on my GT but a lot I've seen are red - what is the correct colour and are they both the same length?

 

Some filters for the Polo are long (like the Halfords one) but the modern genuine ones I use are short and stubby - I always put 3.2l for an oil change but maybe a longer filter would take the 3.5l like the Haynes says.

 

There's always oil left over in the block anyway so don't know if Haynes is quoting 3.5l from factory bone dry or for a typical oil change - and with which type of filter. I presume the long ones were in use when it was written.

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steveo3002

think the short filter is correct ..yes the engine has a little inside but should be near enough

 

i have a red handle dip stick from a abd engine..same length

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oldtech

My dipstick shows more on the upper-showing face than the flipside - I always assumed due to the angle the dipstick tube feeds into the sump at.

 

Is there an easy way to clear or check the breather from the top? Or must the car be jacked/inlet&TB removed for access? I read elsewhere on the forum a blocked breather causes a high reading

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steveo3002

i really dont see how it would , unless due to oil spewing out 

 

take the oil filler cap off if you fear thats causing it ...will vent from there and give a true reading 

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steveo3002

as for checking it ...dunno really , if theres any venting from the pipework then i would say its not blocked , if nothing at all comes from the pipework then myabe blocked , but like i say the pressure woud push oil out of all the seals and dipstick so you ought to know all about it

 

i think theyre an alkward job to change...special tool needed

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oldtech

Ok. I don't yet understand how the breather system or vacuum hoses work or what they do for an engine - will have to read up..

 

Does removing the carbon canister have any benefits?

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steveo3002

carbon canister is basically a filter for fuel tank fumes , instead of venting to air they made that to take away the fumes, most people suggest they wont be working after all these year so take it off to save some weight and tidy things up

 

crankcase vent....well the pistons are like a pump , some air escapes past the rings in normal use so pressure would built in the sump , if pressure was allowed to build it would force oil out like i mentioned before , with the breather its a just a vent to allow it to pass , older cars vented to air , you can also vent to a catch can , the standard car vented to the air filter , which isnt great on a worn engine as its breathing in oily fumes rather than clean air

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dvderlm

could the dipstick  guide tube be moving where it enters the block.

Are you wiping the dipstick before inserting to take a measurement?

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oldtech

The tube is solid. Looks like it's levelled off to maximum now. Thanks for the replies.

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