carbs chucking up oil!

Hi back again with yet another problem

i've got a lot of oil building up in my air filter. its coming up from the carb and im not sure what the problem is.

Any ideas would be much appreciated

Thanks Mike

The crankcase breather is probably blocked. Trace the hose from the air filter to where it attaches to the back of the engine and thats the thing you've got to replace, GSF sell them. You have to lever it out and when you've got it off check that the drain hole down to the sump is clear, a piece of welding rod should do for that. Before I worked this out I contacted our local VW main dealer with the symptons and they told me that the engine was completely worn out and would need replacing. Avoid them unless you're really desperate.
Cheers.

It won't be coming up from the carb.

As mentioned prob from breather, even on an healthy engine oil vapour from the breather fed into the air intake condenses to form oil.

On older and worn engines oil itself can be blown out into the filter by pressure in the crankcase/engine block.

If its not swimming in oil and the engine is running Ok I wouldn't worry too much.

i'd agree about the breather but i would do it as soon as i had the same problem on my driver and left it for ages which resulted in the pressure in the engine getting so high it blew all the seals and the car was getting through a tub of oil a week! more like a sieve for oil really in the end lol.

took the car down to the mechanic today told him i think its the crankcase breather and he didnt seem to agree. i asked him to take a look at it anyways but wont be till next week. he thinks that its piston damage from when i overheated the engine and blew the headgasket a few months ago.

i'd say he's seen you coming with that one. :mrgreen:
for oil to be coming from your carb you need to have it on the wrong side of the inlet valves which are below the carb so oil can't backflow though the carb. unless you carb is set to suck not blow :mrgreen:

ive found out that its not coming from the carb its coming up from the breather but he says if the breather was blocked then id have oil coming out of all my seals. he's pretty sure its piston rings. but i dont really know

if it was rings the car would sound awful as it would be burning oil aswell as fuel. see if any oil is coming out of your exhuast (youll see it forming on the floor behind the car when you leave it running) and check your plugs if they are wet and black then you may have oil in the chambers. if they are dry and black your car is running rich and if they are whity brown the car is fine.

might be the gauze filter in the top of the rocker cover is past it's best and allowing more than vapour to be chucked up. whip the rocker cover off and have a look.
i know my airbox has a build up of oil in it but thats from not cleaning it for a few years.

is the car running rough at all (as i really not as it was)

Hi SKmk1,
The crankcase breather acts as an oil trap, the gauze traps the oil which then runs back to the sump through a small hole. After time, and possibly poor servicing by previous owners, the gauze gets blocked followed by the drain hole, the consequences are obvious. I have fixed two with this problem, one of them would soak a new filter in less than 50mls, they both ran perfectly afterwards with no trace of oil in the filter housing. What your mechanic is telling you is precisely what the VW main dealer told me.

okay thanks alot mate i'll pass it on to my mechanic get him to take a look at what you've mentioned and go from there.

i havnt got oil coming out the exhaust just dirty water.

I've had this before and I spent a long time chasing and replacing parts playing with breathers etc and have recently rebuilt the engine due to guess what PISTON RINGS BLOWN so all I can say is  

It is quite possible that your problem is due to one or more piston rings being blown. I have been working on my engine out of a 1.3 that was displaying the same symptons.
When you say it's chucking it out of the carb can you actually see this happening if you take the air filter cover off and turn the engine over ? Is it failing to start and coughing back up through the carb ? This could point to valve timing being incorrect or valve guides being worn.

The first thing I would do would be to get a compression check done on each of the bores and compare them to what they should be (see the haynes manual), if one or more is low then it is very likely that they are worn/blown. (I would have thought that your mechanic did this)

If you want to eliminate the crankcase breather from the list of possible problems then get a seperate performance crankcase filter to put on the breather hose so that the return gasses are not going back into the air filter box, if it stays clean after this then it's the crankcase breather if it doesn't that's one less thing on the list. (If you don't want to splash out on the seperate filter then just redirect the hose somewhere) but be warned the return smoke from the breather may come inside the car when you switch the fan on.

If you find out it is the piston rings I would advise you to get you're cylinder head checked out (ie valves and valve guides) before doing anything and make sure you can get all the parts you need before you start anything serious. If you do get stuck with where to get parts from let me know and I should be able to point you to what you need.

i cant see it coming up no but it builds up and i jst keep cleaning the air box out. the car runs and drives okay. but best to get it fixed as it will only get worse and possibly cause other problems. im quite a novice when it comes to engines so any work carried out will be done by my mechanic.

My advice would be to buy a new breather and hose, take it to your mechanic and ask him to fit it, if that cures it all well and good. If it doesn't, buy yourself a compression tester, you can probably get one for less than the garage will charge you to do the test, and test it yourself. If you find a cylinder with low compression squirt a bit of engine oil into it and then test again, if the compression increases its your rings or bore at fault, if it doesn't its valve trouble. (Unless you've got a hole in a piston which is highly unlikely).

1.3??

Mines a 1.3 y reg an it has the little dome bit at the back of the block from which issues the crankcase breather pipe.  I heard these were a pig so put it off.  easy peasy actually…
take off air filter.
reach down to the dome thing and using a duff chisel or similarly sharp edged object, prise off the dome bit.  metal is pretty thin though so be careful not to hit it hard or you could puncture it i suppose.#

i just washed mine in white spirit…lots and cleared the holes as best i could.

lots of black crud came out so hoping ive at least made it better.

failing that i got a white in line thingy that looks like a big fuel filter from gsf for ?6 called an oil separator possibly for a later model but could possibly be used if all else fails.