2.0L CU Aircooled. Bad oil leak after running a 500 mile trip overfilled

[Lord-won't-you]

After running a few hundred miles grossly overfilled with oil (I won 't try reading the dipstick without my glasses again   ), I noticed there were a few more drips of oil than the usual very minimal amount I was accustomed to.

I took off the excess oil so it's been running with a normal level, but then a few days ago I noticed a puddle of oil, and drip, drip, drip, dripping when I returned from an 80 mile round trip.

The whole underneath was wet with oil, and the puddle was forming underneath the passenger side (probably due to being parked, so leaning that way slightly due to road camber) front of the engine block roughly inline with the back of the rear wheel. Engine damage aside, it's more oil than I could be happy about dumping at traffic lights, roundabout, queueing traffic etc, I'm a life long biker, and all to aware of the dangers that presents to two wheeled transport.

I suspected the push rods cover seals and rocker covers, but getting my phone camera lens poked above the pushrod protecting tinware, the pushrods seem dry enough, and the oil is coming down the engine block from well above the pushrods. The rocker cover was wet at the bottom, but no drips, and pretty sure the wetness is from the same leak coming down the side of the engine. (gaskets ordered anyways)

So my next thoughts, having looked into T25 2.0L CU Aircooled oil leak issues, I was thinking the oil cooler seals, but although the area was moist, it wasn't running down the metalwork anywhere, and not a drop on the floor under that area. After a run and watching the drip, drip, drip, dripping at the front of the engine block and tinware, that I could expect to see dripping and pooling directly beneath oil cooler/oil filter, if that was the cause of so much oil leaking.

So looking around closely, I've noticed that it's all wet around the oil pressure switch, which I'm thinking from there any leaking oil has a natural run onto the top engine casing, and the path of least resistance flowing forward toward the transmission end of the block, and coming over the side a bit on the way. I've checked carefully around the nearby distributer, and it doesn't look like there's been any oil escaping there.

So I'm assuming it's not the oil cooler as that area of the engine, from underneath, is about the least oily, cleanest part of the whole motor. It looks as if a little oil has seeped over from the leaky pressure switch, unsurprisingly, but not anywhere near enough to be drippy wet, and now feeling reasonably confident that it's the integrity of the pressure switch that's failed.

I guess, the worse case scenario is that it could possibly be from the main seal at the transmission end, but I'm thinking it'd be a push for it to creep up the engine and run along the length of the top casing and ending up at the pressure switch at the other end, even with air cooling circulation howling through there. Fingers crossed, that won't be the case though, as Friday or Saturday, I plan to be travelling up from the midlands to the West Coast of Scotland for a few days , culminating in visiting an old friend on Nth Uist.

I've ordered the relevant tapered thread pressure switch replacement, which should be here tomorrow, when I'll fit it and see, but I just wondered if any more experienced heads than mine can see anything, obvious or not, that I've missed in my deductions, anything else I should be checking.

Thanks, Mart

[Mocki]

The question ( that you maybe wont know the answer to until you have done more miles ) is , is it now loosing oil , has the newly corrected level on the stick dropped ?
With a wbx if you over fill it it will burn , condensate , magically remove the extra oil in a remarkably quick time to where it needs to be on the stick and then not move anymore , mostly out of the breather tower and down through the carb with the fuel i think
I would say you need to clean all the oil off and then you stand a chance of seeing if it’s leaking or has been blown out ?
Are the heat exchangers holding excess oil ? That’s common too .

[Lord-won't-you]

The question ( that you maybe wont know the answer to until you have done more miles ) is , is it now loosing oil , has the newly corrected level on the stick dropped ?
With a wbx if you over fill it it will burn , condensate , magically remove the extra oil in a remarkably quick time to where it needs to be on the stick and then not move anymore , mostly out of the breather tower and down through the carb with the fuel i think
I would say you need to clean all the oil off and then you stand a chance of seeing if it’s leaking or has been blown out ?
Are the heat exchangers holding excess oil ? That’s common too .

Ah sorry Mocki, I should have made that clear. It was a few weeks ago that I overfilled and did the trip. Oil had been at a normal level for a while when this occurred, and yes it's gone from a hair over max to about half way between the lines, over not many miles.

You're right though of course, I'm running twin weber ICT's, with typical pancake filters, and the right hand carb, the one the crankcase breather goes to, had definitely seen some oil, the filter on that side is considerably oilier. I've always wondered why the crankcase breather only runs to the one carb, I'd have thought that'd make a difference between the two, but seemingly that isn't the case, even when it get a deluge of oil. Although the Weber info says the crank breather should be run to at least one carb. I wonder if that's actually saying it may be better to run it from a Y splitter to both carbs.

Although, I ride bikes with basically the same principles, air cooled, carbs etc,  I'm not very well acquainted with the VW Aircooled set up yet, only having the current van since early this year. I had an '89 autosleeper around 25/30 years ago, but water cooled, and I can't remember ever having any issues with that one. Although I'm aware, how much we naturally tend to block out previous traumas 

The current leak is something that's got bad fairly suddenly. I'm not sure how much I overfilled it by, but after a 500+ mile trip, it still had way too much oil in, so hadn't been able to dump its excess in those miles. I relieved it of its excess. Schoolboy error, jeez!

I'll soon see if I was right in my assumptions, as the new sender unit has just arrived and about to swap it over. All fingers crossed, which will make the task more difficult, I know , but I have plans to head up to Scotland, hopefully on Friday, and I'm really not short of jobs that need tending to before I leave. Fitting a fixed panel solar system, so I can cope with being off grid for an extended time, wire in a new 12v fridge and leisure battery, oil and filter change, tighten handbrake (desperately needs it, and what with Scottish hills etc), check wheel bearings swap out the accelerator pump diaphragms (think I've got issues with one of them, unless it's the jet gunked up), fit a diesel heater (probably no rush for that, being summer though).

So yes, I'm praying the oil issue isn't anything too heavy. I'll report back and update later.

[Lord-won't-you]

Sorry, I will get back to this, but not gotten any further with things as a good friend is very sick, taken in to hospital, emergency op etc.

I'm pretty sure the pressure switch was leaking quite badly, and didn't realise how badly until I removed the air cooling rubber boot from around it. I haven't had chance to check if that was the only culprit, but I think it'll probably be the case.

I did discover that the fuel pipe going to the right hand carb has very early signs of cracking, where it's been tightened onto the T-splitter that feeds the supply and delivers to each carb.

I hate to see these vans go up in flames, and would particularly hate to see mine go up in flames, so I'm glad to have caught it. Tbf, I only noticed when examining a photo that I'd taken, so it's not in desperate danger, but I'm not taking any risks with that stuff.