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Wed Sep 04, 2019 4:05 pm

Purchased a baja bug a couple years ago and have been enjoying it ever since.
On a recent trip, I noticed several drops of oil after a quick stop. Checked and oil was about a half quart low. Topped it off and kept driving.. same thing. Long story short I lost a little over a quart of oil in 175 or so miles. Seems to be leaking from the seal behind the crank pulley.

Driving conditions- avg speed 60mph. Ambient temp 70 degrees (Northern Michigan). Oil is Royal Purple 5w30. Oil temp measured at the pressure relive sensor via VDO gauge averaged 190-200, pressure somewhere around 35-40 psi when cruising.

Motor is a type 3 converted. I have had oil pressure problems before, eventually found TWO springs in the pressure relief plunger hole.. it now only has one, which I believe to be stock strength, not Heavy Duty. I do believe the oil pump is larger than stock but have not opened it up to see.

I did check for end play (although I have never dome this check before). When applying pressure with a crow bar to push the pulley out, there is no visible movement. Pushed hard enough to see the pulley begin to flex.

Vent in the fill tube is just a rubber hose vented to atmosphere. Checked and it is clear without obstructions.

Ideas? What to check next? I do have a slight gas smell in the oil. Other than that the car starts easy and runs well.

Other engine thread-
https://www.thesamba.com/vw/forum/viewtopic.php?t=691823&highlight=

Wed Sep 04, 2019 8:40 pm

Stock from VW there was no crankshaft seal. There was a big cupped washer to deflect some of the oil from escaping and the stock pulley has spiral / threadlike grooves on the outside of the hub to push some more of the oil back into the case. Not a seal like the flywheel seal or input shaft seal. It is not a great system.
Your aftermarket pulley may not have those grooves? The grooves may be full of dirt? Washer missing?
There is a product called a “sand seal” that can be installed, I have no experience with them but I believe they require minor machining of the case to accommodate the seal.

I don’t like your case breather arrangement. VW connected the breather hose to the air cleaner so the sucking of the intake exerted negative pressure on the interior of the case. This helps a lot with minimizing leaks at places such as the crankshaft pulley.....

Thu Sep 05, 2019 5:21 am

If the oil smells like gas I would confirm if it does or not have gas in the oil. Could be the fuel pump leaking and the oil is thinned and leaks more.

Thu Sep 05, 2019 5:33 am

I have not previously noticed leaking oil here.. at least not this much. Leading me to not believe the pulley is the main problem.

I did recently change the fuel filter (replaced with the same as before) and the air filter (replaced with the same as before).

I can try running the tube to the connection on the air filter to draw some vacuum.

What are the possible sources for gas in the oil?

- Fuel pump.. pull it and check for..? I did rebuild the original pump on my 1962. This one seems to be a cheapo knockoff.

- Leaking from carb, possibly stuck float? I do adjust the idle screw on the carb depending on weather.. idle higher in the winter, partially due to no intake preheat tubes.

- piston blow by? I have not compression checked the motor. It appeared to be fresh when I bought the car, but have no receipts. Guessing it was assembled cheaply, and possibly from someone without a ton of experience. Did a full oil change removing the stock 'filter' after buying and did find some orange gasket material in the filter.

Anything else I should check?

Thu Sep 05, 2019 8:12 am

Did you check the oil level? When the fuel pump goes bad it leaks fuel into the oil, thins the oil and could raise the oil level. Too much oil and it will leak from behind the pulley.

Thu Sep 05, 2019 8:32 am

Vanillagurilla wrote: Did you check the oil level? When the fuel pump goes bad it leaks fuel into the oil, thins the oil and could raise the oil level. Too much oil and it will leak from behind the pulley.

Oil level has not went above the 'full' mark that I have seen, it was still leaking down past the halfway mark on the dipstick. Didnt let it get much lower. Oil level definitely goes down after driving.
No noticable smoke, just a slight gas smell to the oil.

Wondering if my full mark on the dipstick is correct? Its a type3 case with the empi conversion to normal dipstick..

Thu Sep 05, 2019 8:41 am

After checking all of the above for oil dilution from fuel. You can pull the front pulley off to see if it has a sand seal installed. They have two types, one is a seal installed in a case that has been machined to accept it. The second type is a seal installed into an adapter housing that is then installed in the stock
non- machined case.

Both types are easily replaced if you have them. On both types the pulley should have a smooth metal sleeve installed on it's snout for the seal to ride on. They do get seals wearing a groove in them sometimes.

The non-sand sealed type aluminum pulleys have the spiral grove cut in them like the stock steel pulleys and can not be used with a sand seal.

Pay close attention to the leak and make sure it is not leaking from the oil pump/case sealing area. Leaks there might fool you into thinking it is from the pulley.

Thu Sep 05, 2019 9:38 am

Clean the area well with brake cleaner and a towel etc then use a white powder spray (foot spray) and spray around the area and start up and see where the leak is coming from.

Sat Sep 07, 2019 8:08 pm

And get that fuel filter away from the exhaust pipe!

Eq

Sun Sep 08, 2019 8:52 am

I had trouble with a type 3 case conversion with the dipstick tube allowing oil to push out the top. I put an o ring there to stop it.
Dennis

Tue Sep 10, 2019 6:16 pm

I don’t want to poach this thread, but I am having the same problem. I did not have any oil leaking from that area prior to changing my flywheel main seal last week. Main seal seems to be fine after install, but now this. After putting engine back together and during the process of starting the engine, there was a huge backfire from gas that someone helping me, had poured into the carburetor.

Would a back fire possibly have caused this issue?

My oil dripping from behind the pulley also smells like fuel. Breather not obstructed.

I read that stock pulleys didn’t have seals. Is that correct? If so, then why am I removing the pulley? What is to fix? A new pulley?

Thanks!

Tue Sep 10, 2019 6:44 pm

I personally have noticed on my own car that checking the oil level immediately after driving gives erroneous results. As long as the oil is above the low line, I leave it alone until it has sat and cooled off, preferably overnight. The oil in the cooler will drain back some, and then the level will be accurate. It is possible you had a small leak, and then unintentionally overfilled it. Just my thoughts.

Also, the threads on the crank pulley spin oil back into the engine, yes, but it also pushes some fresh air into the crankcase, which should then be evacuated by the breather hose receiving vacuum from the intake/carburetor. Without proper vacuum, the crankcase is likely being over pressurized.

Wed Sep 11, 2019 7:47 pm

Something I just thought of... have you checked the torque on the case? I had a few that were off. I also get some oil from behind the pulley but only when I overfill it (on purpose) or rev it up past 5k.

Thu Sep 12, 2019 3:44 pm

Torqued tight on main seal. Never touched crank pulley (yet). I have been researching the "oil slinger", blow back and all threads related (samba and other). Gonna drive and see if leak goes away, "if" overfilled. Thanks Vanillagurilla.