NEW G40 OWNER-HUGE OIL LEAK/BREATHER SYSTEM PROBLEM

[Mog Dog]

Hi there G40owners and enthusiasts! I am proud to say that i am the new owner of a Alpine white VW POLO G40 mk3 1993 and am really happy with its looks and power! The car is a little rugged around the edges as is to be expected from such a classic car and needs some tlc on the cosmetics. There is however a huge oil leak or should i say explosion which has splatted up onto the underside of the bonnet which we susspect is due to an issue with the breather system which has been modified with a crankcase breather filter. We are still unsure the the precise location of the leak but i belive that it is coming from the dipstick or maybe the cranckcase filter itself.
 We have hit a wall with this now and will apreciate any information regarding this issue.

J have put some pics of the car and the engine on photobucket as i had problems uploading in here http://s32.photobucket.com/user/mogdog1/library/Mobile%20Uploads?page=1&sort=3

[GR40]

Yeap! That filter is way too small in diameter to vent enough vapors out of the crank and when the pressure is build in the crankcase it shoots oil out of the dipstick. I would remove it and let in vent to the atmosphere for the time being rather than running it like this. You should get either a bigger breather filter or an oil catch can with at least the hose's diameter asap. You are risking running the engine out of oil this way! I know, cause I have managed to do so in the past with a similar contraption.

[Mog Dog]

Hi there friend! Thanks for the reply, so do i not really need to have the filter on the pipe to run it? I an not even running it at the mo because i am unsure if i will damage it and you are right i have used two bottles of oil trying to figure this out but if i could atleast run it u till i get the new parts that would be ideal! It is just staring at me through the window 😭😭

[Mog Dog]

Have removed the cranckcase breather filter and took her out for a supercharged run but unfortunatly it was slightly worse, i now belive the oil is shooting out of the breather hose that the cranckcase filter is attatched to as on the underside of the bonnet directly above this pipe the main splatter zone with significantly more oil than when the filter was on.

Havnt go a clue!! 😂

[GR40]

Did you remove just the filter or everything that is jammed into the hose coming from the breather? If you just removed the filter u didn't do much! You need to have the entire diameter of the hose in order for it to breathe fast enough and not pressurize the crank. If removing everything doesn't stop it from shooting out oil then you might have a bigger issue than just hammed breather.

[GR40]

I just measured my hose from the crank and its around 2cm on the outside that means that is has at least 1,5cm internal diameter, if that is of any help to you!

[Mog Dog]

Hi again! Well thanks for all if the info, like you said i did not remove all of the attatchments from the hose and i have removed it now and i did notice a reduction in the oil spatter. However i managed to get hold of the guy who has rebuilt the car after blowing the old engine and sourcing a new G40 engine and he has done loads of mods to make it faster, and he is saying that the oil is coming from the boost return and i need a catch tank.

You mentioned the possibility of if it wasnt the breather that it may be worse, what kind of issues amy we have here? Could the crankcase be blocked? I havnt got a clue what else it could be.

A little bit more info here, on the way hime he said not to go over 3000 rpm and see if no oil comes out and i took it to 4000 and nothing was there when i hot home. Dont know if that helps but the car is serously fast, i have put it through its paces and put a brand new 208 gti to shame in the moterway haha i love it!!

[Mog Dog]

Well have been looking at some things and i think that the oil is coming from the boost return 😭 I belive this means i need a supercharger rebuild. Its cool i was planning on spending money on it but didnt expect this 3 days after purchase. it has a 65mm pully so i think that means a rebuild every 10k miles although after meeting the guy who rebuilt this it is evident that he ragged the shit out of it, give him a go and was in the passenger seat and shit it felt even more crazy💨💨

Any advice is always apriciated 👌

[GR40]

While you are at it, either block or put a filter on the second hose going to the charger, the way it is now its pulling unfiltered air from the hole on the valve cover and probably other stuff along with it.

[GR40]

Take out the bottom hose of the charger, if there is a tone of oil in there then an oil seal has gone bad. It's normal to have some oil in there but if the bottom of the intercooler is filled with oil then that might give you a clue on what is going on.

[PeteG40]

the crankcase breather is waaaaay too small.  Needs a good inch diameter internally.

This will pressurise the crank case and force oil out wherever, up the dipstick - out of the filler - past charger oil seals - even can blow charger oil seals.


1. Remove crank case breather pipe and bin it.
2. run with it just venting to air - until you get a better sized pipe (with no kinks in either!) or run the stock boost hose on it!

Then when that's fixed, you might need an oil seal replacing in your charger!

[Mog Dog]

Thanks for everything lads but i think it might be even worse, there is a water leak now and im scared i have cracked the block.

Where is the best place to take the car to be looked at? Dont think a standard garrage would do it.

If i cant get this fixed there will be a lot of g40 parts on here real soon.

[Mog Dog]

Ohh yeah and i have got a 1993 polo GT In alpine white with the deal so parts x2 🤑🤑🤑

[hayesey]

Where is the best place to take the car to be looked at? Dont think a standard garrage would do it.

why not?  It's just a car, any back street garage will be able to do it.  I wouldn't get them to do a charger rebuild but everything else on these cars is mega-simple in comparison to almost anything built in the time since they were new.

[Mog Dog]

Yeah you right man was a bit pissed off with it when i sent that! Lol im gunna find a good local garrage and take it on the weekend. I was counting on it running smooth for a short while befor i had to take it in, was told it was all good but gunna have to pull the cash from somewere!!

Anyway its the water pump and not a cracked block so thats good, i will get this car running and looking ace when i have finished with it 😎