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Well my travails continue.  After 40 miles my new engine began to leak.  Returned home to find the entire engine compartment covered with oil.

I placed a sheet of cardboard under the engine over the last week.  Tried to position it in the same spot between drives so I could localize the leak.  I clean the engine compartment after or before each drive. 

The cardboard shows where the drips are.  The most from the rear -- perhaps the pully seal?  But lots of drip down the middle and up front too.  The dark patches to the left and right on the brick aren't oil -- just dirt.  The driveway slopes down maybe 4% so some of the drips in the middle might be migrating down the engine bottom from the front.  What is up front that might leak?????




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@Marshall  Oil in the engine compartment? ( above the tins???)  

Maybe worth checking a couple easy bits - not involving pulley nuts or engine case.

Above the tins you only have a couple items that run oil above the tins, & that can splatter oil above your tins all over the compartment ( in your engine compartment).

- the two lines that run oil on a traditional VS build... ( line to & from external oil filter, and your breather line/ lines if you have a more complex breather system).  Maybe one of them is loose- or has a cut/nick.... And under pressure leaks/ squirts oil out,,,  the lines are right next to the belt/ pulley, And breathers is typically mounted against the fire wall / fwd of the engine in the compartment which can then help spray oil everywhere.

I DELETED the portion about the oil filter lines ABOVE... MY BAD. They run under the tins.

- or... your oil dipstick not in the hole. ( and when the engine is running oil is sputtering out. Again next to the belt/pulley, which could help spread the oil everywhere). 

- also worth checking your oil cap is on tight... not loose.

Other than those lines, and your oil dip stick there is no other systems above the tins that could leak- spray oil all over above the tins. ( that I’m aware off... but I am not a mechanic, though I play one In my garage on the weekends ;-))

have you tried looking in the compartment with the engine running... with someone reving up the car  to see if something “squirts out”.

a picture would help, if you want assistance identifying your oil lines, breather lines, and were your oil dipstick is located.

Last edited by Lfepardo

I had a similar problem the first year or so with my car.  Everything in the engine compartment would get a sheen of oil on it after driving a while.  I tried all of the common things (oil temp sensor, dipstick, etc.), but it turned out the the cast aluminum pedestal the the internal oil cooler mounts to was a porous casting and wept oil even though no holes were visible.  Since it's inside the cooling shroud the fan would blow an oil cloud all over everything.  It was a bear to find and fix, but a new pedestal cured the problem.

EDIT: This didn't make the engine leak free, but the upper part in stayed pretty clean after that.  There were still the usual pushrod tube leaks and others.  I just lived with it.

Last edited by Lane Anderson

Marshall,  Just wondering what size motor you went with.  If you are building too much crankcase pressure and not releasing it, through a breather, it might be coming out of the weep hole behind the pully, make a mess in your engine compartment.  I had this issue on both my speedster with a 2176 and after I re-build the 912 motor to a 1750.  After adding a breather, no more oil all over the engine. Stock breathers off of the oil fill are not enough to release the pressure.


Last edited by BADSPD - Stephen

Marshall,  Just wondering what size motor you went with.  If you are building too much crankcase pressure and not releasing it, through a breather, it might be coming out of the weep hole behind the pully, make a mess in your engine compartment.  I had this issue on both my speedster with a 2176 and after I re-build the 912 motor to a 1750.  After adding a breather, no more oil all over the engine. Stock breathers off of the oil fill are not enough to release the pressure.


And if whoever built the motor didn't put the oil slinger/washer on the crank, you'll never stop the oil spray.

Also, if it's a motor with some piston ring/cylinder wear, the blow-by pushes oil out of the pulley. The only way to stop it is a top end rebuild.

What are your engine specs, @Marshall?

Almost any modified T1 engine able to rev to 6500+ RPM or with a larger bore (especially with 94s) will pressurize the crankcase enough to push oil out from behind the crank pulley. In an amazing act of courage and hopefulness, the Sainted German Engineers didn't see fit to put an actual seal there-- they relied on a "slinger" and some grooves cut in the pulley hub to get the oil back in the crankcase.

With increased displacement, there's an enormous amount of swept area in the cylinders, with the pistons creating all kinds of turbulance inside the size-tiny crankcase. Add a little (or a lot, depending) of blow-by past the rings, and you've got a fair amount of pressure built up. By far the easiest place to relive that pressure is at what would be the crank seal, assuming there was a seal (which there isn't).

Almost everybody puts a cute little breather box up high, and tries to relieve as much pressure as possible through it, but at the end of the day-- unless you've got a really, really good ring seal (and you probably don't), oil is going to push out from behind the pulley. the pulley picks it up and throws a nice line across the inside of your deck-lid, and surround tin. It's how you know there's still oil in it.

You can help a bit by reducing the oil level in the crankcase, assuming you have an extended sump, but keep in mind that this is playing with fire. Running out of oil in a long sweeping bend is bad for the soul.

As hard as it is to accept-- if you like bouncing off redline, you're going to spray some oil around-- especially if you have a stroked engine, and double especially if you have 94s. Some battles are possible to win, others are mostly "managed".

If you hate it (and I do)-- you can always dry sump it, get thick-wall 92s, go with Deeves rings and a Total-Seal second, and hope for the best like (*ahem*) some silly people. Otherwise... acceptance is the final (of seven) stage of grief.

When I was perusing The Samba prior to redoing my PCV situation, there was some back and for about venting valve covers, the con being that the airflow impeded oil drainage back down the pushrod tubes. 

Most info pointed to it being unnecessary in a <2L motor so I didn't consider it. Plus, given my Spyder has an electric fuel pump, I have a whopping 1/2 hose coming out of my block-off plate that your Speedsters probably don't have.

Despite this, I'll get a few drops out of my valve covers and pulley after a long slog at high rpm. Not enough for me to really worry about. 

1642cc. I do not redline the car. Typically Shift around and maintain 3-3.5 rpm. I tracked oil usage. Drove 100 miles over one week and needed 1/2 quart to near top up the oil.

Luckily I’m taking her to a very qualified mechanic who will shed some light on all of this. I will be sure to pass on the three or four very useful and specific suggestions that all of you have so kindly given me.



Marshall, on a 1641 you shouldn't be using that much at all. If you get a bigger motor in the future, maybe our experiences can help you.

Stan explained what is happening in a larger aircooled type1 very well.

I had a never-ending(worsening?) blowby problem. I vented the valve covers and case(1/2" ID hoses and fittings). I built a large 550-style angled tube breather. I installed a sand-seal. I even installed an rpm-controlled solenoid that evacuated vapors into the exhaust. Still got vapors and mist all over the engine compartment.

So then I went down the dry-sump rabbit-hole. Stan was happy to have the company LOL! I tried different breather arrangements, along with the dry-sump. Still had oil mist.

Last summer, I rebuilt the top end of my motor. New Mahle forged pistons and cylinders. Used Total-Seal for 2nd compression ring and oil scraper 3rd rings. Sent the heads out for guides and re-cutting the seats. I bought a Gene Berg case-cutter and cut the case, and installed the GB double lip seal. Along with the rebuild, I changed the main case breather. I enlarged it from 1/2" to 3/4" ID, through the distributor hole.

It is now much, much better, but there will always be a little mist when I rev up to 6500. If I keep the revs below 5000, the engine stays very clean. But if you play up there where it sounds SO good, there will be some oil mist generated that will overwhelm whatever system you have in place to prevent it.

Last edited by DannyP



I'm glad you have somebody you can trust-- but I'd recommend following the advice of RR, "Trust, but verify". Knowing a few things as you enter into dealing with the mechanic means you aren't flying blind. Forewarned is forearmed.

Difficult to find and fix oil leaks almost always come from the crankcase being pressurized, whether it's and oil mist blowing out behind the pulley, or pushrod tubes, etc. There is pressurized oil in the galleys, and there will sometimes be leaks at threaded joints, seals in the oil cooler, etc.-- but most of the hard to correct leaks are from crankcase pressure. 

Cylinder piston ring seal is what keeps the pressure in the upper half of the cylinder where you want it, and out of the bottom (which is the crankcase) where you don't. If the valves leak by, it will pressurize the intake or exhaust, but not the crankcase. If you have a pressurized crankcase, the pressure is coming from the pressure in the cylinder leaking by the rings. It could be worn out rings, but in hot-rodded Type 1 engines, cylinder distortion is a real problem. As the cylinders heat up, they expand. The thinner the cylinder wall, the more they distort as they expand (making a good ring seal very difficult). This is an instance where more material is always better.

A stock 1600 Type 1 cylinder measures 85.5 mm and is 4.15 mm thick at the top of the cylinder. These cylinders are great, but it's hard to make power without displacement, and the fastest way to increase displacement is with a bigger bore size.

A 94 mm cylinders used in 1915s, 2276s, and 2332s are 3.55 mm thick and often have distortion issues in engines running higher compression or higher RPM, unless a guy is very, very careful with ring selection and cylinder prep (most people are not ). There is a "thick-wall" 94 mm cylinder, but it's very rare, and not very effective, because the outside of the cylinder needs to be grooved for the head-studs to fit, and this creates thin spots. JPM in Sweden makes a 94 mm cylinder out of some super-special iron, and makes them as thick as possible (to be used with 8 mm head studs, etc), while holding a constant cylinder wall thickness. They cost about $1000/set of 4, without pistons or shipping.

The Mahle 90.5 mm cylinders everybody uses in 1776s and 2110s are 3.75 mm thick, which is why everybody uses them for "happy" engines that don't spit a lot of oil. AA makes a "thick-wall" 92 mm cylinder that is 4.55 mm thick, which is the king of the hill in terms of wall thickness, but the pistons in most of their sets are not forged. Now, if JPM made a thick-wall 92 with the super-special iron, and sold them with a set of JE pistons running Deeves rings and a Total-Seal second, we'd probably never throw a drop of oil.

If your engine really is a 1641, then it is a stock stroke engine with 87 mm "slip in" cylinders. The stock 1600 cylinder bore is 85.5 mm. The only way for the cylinder with a bigger bore to fit in the stock case register is for the cylinder walls to get thinner (a lot thinner). 87 mm "slip in" cylinders are 3.4 mm thick-- thinner than a 94, thinner than anything commonly used except an old Mahle 92 mm cylinder (which measures 3.0 mm and is not recommended by anybody).

The 88 mm "slip in" were the thinnest of any cylinders ever used. They are only 2.9 mm thick. For reference, that's only .11". I think they were a thing for about 10 minutes in the 60s and nobody's used them since.

Last edited by Stan Galat

Please forgive my simple question, (because it happened to me with my original 1641) but are you sure you're not over filling the oil.  I did it when I thought the oil should be filled to the line on the dipstick when the engine was cold. What a mess and the engine always leaked after that.  Everywhere.  

In my new engine with an extended sump I leave the oil 1/2 quart low.

Hope you get this thing sorted out. Luck


I’ll preface this by saying that I haven’t tried the following on either a type 1 or type 2 VW engine. And this is not a recommended solution to the OP’s problem.  It might be useful on a crazy performance project though, or just for your entertainment, so here goes.

There have been a couple mentions in threads lately about crankcase ventilation.  It reminds me of how we cured a similar problem with a 750cc sounds of singles road racer I built back in the '90s.

Background on the motor: This was a 750cc high compression single based off of a Honda 600cc engine.  It ran high compression (10.5:1), a cam with a lot of overlap, and it was in a race bike so it regularly (every shift) was revved over 6,000rpm.  The crankcase was small like in a type 1.  You could think of this as 1/4 of 3,000cc 4 cylinder, only worse, because as the piston came down towards the crankcase there was no opposing cylinder moving away from the crankcase maintaining the crankcase volume like in a multi cylinder engine.  Even without blow-by it can pressurize the crankcase. The engine was designed with a dry sump oiling system.  I figured that would be enough to keep crankcase breathing issues under control, along with an enlarged crankcase vent that went to a bottle that vented to atmosphere.  The tiny little stock vent hose with a little flapper valve was deemed stupid and thrown on the scrap heap.
During its first dyno runs there was oil mist all over the back of the bike.  It was from the vent bottle, so an aluminum container was fashioned, stuffed with a stainless steel scrubby pad, and a hose run out of that.  On the dyno it looked like the problem was solved.
On the track this set-up proved that oiling the rear tire was not conducive to rapid lap times…or even staying upright.  We were filling up the tiny vent tank.  Much colorful language ensued.  We weren't going to run a 2 gallon vent tank, so the Einstein crew ran small air filter fixed to the vent hose.  That was a hard no in a 10 lap race.  We were still filling the vent tank until the filter was soggy and spitting all over the place.  This was not going away by rerouting vent hoses. Hmmmmm.
Around this time one of us was reading about some of Smokey Yunick’s crazy NASCAR engine tricks.  We discovered that he had a simple way to create a slight vacuum in the crankcase that was so effective NASCAR outlawed it. We tried it.  It worked. We even picked up power on the dyno.  Cornering also improved without the rear tire being coated in 20-50.  So what was this trick that cost us ten bucks, some scrap and a little welding time?
The bike ran a separate header from each exhaust port to a collector, then one pipe to a reverse megaphone, a 2 into 1 if you will (this things was so loud it scared grown-ass men). We drilled into the exhaust pipe just after the collector at a 45* angle in the direction of the exhaust flow. We fish-mouthed a short 1/2” ID pipe so it would be flush with the header and welded it onto the header at the 45* angle. Then a 1/2” hose was attached to the pipe and run to the new larger vent tank. A PCV valve was installed in the line with air flow allowed toward the exhaust fitting. You carb theory guys know exactly what's happening here.
Problems I could see on other engines might be creating too much and vacuum sucking seals, O-rings, or gaskets into towards the engine.  One could also tune it a bit using different hose sizes or PCV ID's if needed.  On our particular application it actually pulled the seals against their stops and it was all good.  In a type 1 you’d probably have to use tabs on the valve covers to keep the gasket from being sucked in and creating a leak there.  That Smokey was as fine a natural born engineer as ever walked the earth.

Stan, spot-on as usual.

Al, great point! Only run the oil low on the dipstick IF you have an extended sump. With only 2.5 quarts of oil in a stock sump motor, I would NOT run it low. I'd be really nervous about running it dry. On the other hand, an over-full crankcase WILL throw oil out everywhere and is bad for your motor as well.

Yes, it will certainly complicate that. An external filter and lines(depends on how long) should add about a quart, if you have the full-size Ford-type filter most run. 

If you have the filter that is ON the oil pump, they are usually smaller, maybe a half-quart.

If you have an oil thermostat and a cooler, it will be more oil......

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