Oil leak form crank pulley

Fanatix · Post by **Fanatix** » Tue Nov 27, 2007 9:23 am

Hi ppl..

I have a 1970 vw beetle. 1600 twin port..
there was a small oil leak from the crank pulley..
I was advised to buy another pulley which is about 0.5mm oversize
to solve the problem..But after installing the oversize pulley the
leak is still there..What could it be?
Spoke to someone who advised it could be the thread on the block
that is worn out and nothing can be done to fix it..
Is this so..
Can any1 please help..

Merlin · Post by **Merlin** » Tue Nov 27, 2007 9:25 am

OK, I REALLY am not the person to ask about type of stuff, but from what I've heard about my engine-in-progress...

Yes, check the scroll. Perhaps it's 1mm?

I think you can have a "Heli-Coil" fitted?

Anyone else care to clue both of up?

N.

Post by **calooker** » Tue Nov 27, 2007 10:54 am

Several possible problems, scroll on pulley could be the wrongsize,
slinger left off the crank during engine build, or the opening on the case out of round, too much oil in the engine block, too much crank case pressure, breather will help but it's not resolving the cause only helping with the symtoms (I sound like a doctor).
There is a way to stop the leak, you can fit what in the US is known as a sand seal, needs special ally. pulley and seal as well as machine work if it's to fit right, you could get away from the machine work with a smaller dia. seal and corresponding ally pulley, but if the case opening is out of round then the seal will not fit right.

Fanatix · Post by **Fanatix** » Tue Nov 27, 2007 11:46 am

wat is an ally pulley..sorry..iam not mecanicaly
inclined

Merlin · Post by **Merlin** » Tue Nov 27, 2007 11:54 am

Aluminium pulley.

Fanatix · Post by **Fanatix** » Tue Nov 27, 2007 4:26 pm

where wud i get this seal..
thanks for that explanation merlin

Riftvalleyvw · Post by **Riftvalleyvw** » Tue Nov 27, 2007 6:05 pm

Ok. The sand seal will not stop the oil from leaking from the pulley. It is designed to keep sand out of the motor.
If you have a leak from there, there are 3 possible problems. One is Blowby from a worn motor (most probable) and the second is that there is too much oil in the crankcase and the third is that tthe crankcase breather is not hooked up correctly.
First check if there is a hose connected from the oil fill to the air cleaner of the carburator. If you have an older motor there might be a metal tube that goes from the oil fill to under the car. Straight down. But you have a 1970 so there should be a hose. If you dont have the stock aircleaner it can also cause the problem. Make sure that the gasket inside the oil fill cap is there. This setup creates a suction inside the crankcase to keep the oil leaking from the pulley. Air is supposed to enter the crankcase behind the pulley and be sucked thru the motor then in to the carb.. If any of these parts are missing, you will have oil leaking at the pulley.
If the cause is blowby, it means that your motor is worn and will need to have new rings or cylinders installed. If you cant afford it right now, You can drill a hole and attach a 3/4" piece of hose to your valve covers and run two hoses to your air cleaner. this will stop the oil leak. It is standard practice to do this to proformance motors.

Also The scroll on the pulley is not for oil control. It is designed to pump AIR into the motor. Now some of the aftermarket manufactiurers are not so smart and they think that this scroll is for oil so they only put a few threads on the end of the pulley. You dont want this type of pulley. You want the ones where the scroll goes all the way from one end to the other without stopping.

Merlin · Post by **Merlin** » Wed Nov 28, 2007 8:50 am

I've just had a brilliant idea for Fig's KKK meet next year...

We'll all club in, get Rift down to ZA, and take him to the meet...

Then we'll have a face-off, kind of like those old debate TV gameshows.

IMPI vs. Rift.

Can you just imagine

Now that, would be impressive.

N.

Chris · Post by **Chris** » Wed Nov 28, 2007 8:57 am

And TonyZ as an interviewer.

Post by **Bugger** » Wed Nov 28, 2007 9:38 am

Post by **calooker** » Wed Nov 28, 2007 10:58 am

[quote="Riftvalleyvw"]Ok. The sand seal will not stop the oil from leaking from the pulley.
Sorry, I don't share your opinion on that one, why is there a seal on the other end of the crank?
Type 4 and WBX has seal on the pulley.
As well as all Porsche engines.
All the last EFI AC motors have them too.

The down pipe on the bottom of the filler is a condensation outlet.

Post by **Tony Z** » Wed Nov 28, 2007 2:12 pm

Chris wrote:And TonyZ as an interviewer.

No way, you have the gift of the gab, not me. I'll be the moderator....

Merlin · Post by **Merlin** » Wed Nov 28, 2007 2:39 pm

Typical Manager...

The runs can do the work...Tony will "moderate".

N.

Post by **Tony Z** » Wed Nov 28, 2007 5:23 pm

just keeping tabs on all you guys... call me watchdog

Riftvalleyvw · Post by **Riftvalleyvw** » Wed Nov 28, 2007 6:53 pm

calooker wrote:
Riftvalleyvw wrote:Ok. The sand seal will not stop the oil from leaking from the pulley.
Sorry, I don't share your opinion on that one, why is there a seal on the other end of the crank?
Type 4 and WBX has seal on the pulley.
As well as all Porsche engines.
All the last EFI AC motors have them too.

The down pipe on the bottom of the filler is a condensation outlet.

Ok The flywheel seal is there because it keeps the presurized oil from the crank bearing from squirting out of the motor. If you look carefully at the bearing journal and the seal you will notice that there is a space between the two of them. This is a cavity that is designed to hold oil to lubricate the seal. If you look carefully at this chamber you will notice a drain hole. the hole is not on the bottom of the chamber. It is at about a 7o-clock position to allow oil to be traped in between the bearing and seal to lubricate the seal. This is standard seal design technology.
The bearing next to the pulley is inside of the motor, so the oil will flow from the bearing and pour out into the pan. If you install a seal here it will quickly fail because of lack of lubrication. If you look closely you will notice that there is a small chamber with a drain hole in the bottom cut into only one side of the case. Inside this chamber is a concave oil slinger attached to the crank that keeps the oil from squirting out the pulley hole. VW could have eaisly done the exact same thing that they did at the flywheel seal and put a seal at the pullye, but they didnt.
The reason for this is that familiar problem called blowby. VW motors are designed to be inexpencive. Hence no valve stem seals and less complicated piston ring seals. Both of these leak slightly. a good nice tight motor will have just a little blowby at idle and more at acceleration. Most people realize this because if it is severe a lot oil sprays out. But what most people dont realize is that blowby goes in both directions. not only does the over pressure when accelerating blow out but when you are decelerating the air is sucked into the cylinders from the crankcase and valve stems. This is where the opening at the pulley comes into play. the air is drawn in there. if the opening wasent there, the air would just get sucked out of the carburator, causing problems with the operation of the car. When people set up theirr cars for off road use, they are worried about sand being suicked into the pulley hole because of the suction. So they put a seal there. but in combination with the seal, they put vents on their valve covers and breather boxes in to help vent the crankcase. The seals typically doi not last very long maybe 8,000 km and it is time for a new one. There are 2 types of them. There is a press in type and a type where you machine your case with a took that will attach to your crankshaft. The press-in one is garbage. Of course if you were off road all the time it would make sense to bring along a few extra seals and change them from time to time as they pop out, but for a street car, they are sensless.