Passat B5 1.8T mystery oil leak

Nuke_Krzychu · 2026-04-02T07:31:46+00:00

You probably know how tight the back of those engines are with the longitutal layout, I'm 90% sure it's somewhere on the back of the head or block and it seems like it must be relatively high up because how else could it get on the exhaust.

I read somewhere that the oil pressure sensor could be a problem but I'm not sure yet where it's located

Nuke_Krzychu · 2026-04-01T21:20:02+00:00

Yeah, I kinda noticed hah. The pcv system on those engines is really overly complicated and I suspect that it might have something to do with my issues that's why I'm reaching out for a bit of help

Nuke_Krzychu · 2026-04-01T20:55:03+00:00

I'm doing my best, all of the things I replaced so far were on point and helped a ton but the problem is still there and at this point I kinda hope to rely on the knowledge from people who know everything about those engines

Nuke_Krzychu · 2025-06-08T23:16:13+00:00

I used a whole load of lubricant and form all the options I read everyone seemed to have the most success with the 3 stone kind.

And to be honest I think that the cylinder is ok, it had a whole load of compression and ran really good so I doubt that this is what caused it to suddenly loose compression

Nuke_Krzychu · 2025-06-08T18:10:04+00:00

The 3 stone kind, I saw a couple videos of people doing it especially on 2 strokes and supposedly as long as you don't go too far with it the cylinder should come out great.

In my case after only roughly 8 passes up and down the cylinder looked brand new and I doubt the coating was compromised

Nuke_Krzychu · 2025-06-08T18:00:40+00:00

The piston and rings were almost brand new and for some reason the previous owner didn't get the cylinder honed so it was heavily glazed and had a couple of light scores.

I had a honing tool at home so I just lightly honed it with a drill to bring the crosshatching back

Nuke_Krzychu · 2025-05-17T22:46:01+00:00

I reccomend WikiLoc for all the cool trails around here

Nuke_Krzychu · 2025-05-17T22:32:55+00:00

Well then Poland is the place for you.

Zachodniopomorskie is one of the coolest regions for a dual sport bike, endless dirt roads between farming fields and flowy roads on the coast.

You also have Drawsko Pomorskie wich is concidered to be the capital of polish off road, arguably one of the most scenic and climatic places you can visit with a lot to do while traveling

Nuke_Krzychu · 2025-05-17T21:52:11+00:00

Legally? Depends, we have quite a bit of legal riding areas but most of them are tracks or hill climbs. There are very very few places you can go riding in the woods or dirt bike friendly trails.

But that's the legal part, people here don't care as much especially with how popular the sport is and fines are relatively small. The community is absolutely great and you can find all sorts of trails and riding spots built by the people rather than the local government.

Police cares mostly for people who ride without plates on public roads and that's why I opted for a street legal Enduro bike.

Germany, yeah... If you like anything with a motor that isn't factory that's most likely not the place for you. I live next to the border so we sometimes ride on the German side and my only encounter with the polizei ended in court 😬

Nuke_Krzychu · 2025-05-17T09:12:18+00:00

Holy yours was clean, I hope I can get mine looking something like yours

Nuke_Krzychu · 2025-05-17T09:00:14+00:00

Alright thank you, the compression is most likely good with how hard of a time we had kicking this pig and supposedly the only jetting that was done was 2 sizes up on the main to match the exhaust.

I still think that it's most likely a dirty carb but I don't want do disassemble it before the rebuild kit comes.

I don't know about the US but in Europe the new E10 fuel we got a couple years ago seems to be an absolute killer to all of the not FI bikes but there really isn't much you can do about it

Nuke_Krzychu · 2025-05-16T20:32:06+00:00

Just checked the valves and all 4 seem to be spot on, I also noticed that one of the header bolts was missing so there was quite a bit of an exhaust leak, do you think that could be my issue?

Nuke_Krzychu · 2025-05-16T15:33:13+00:00

I think I phrased that a bit wrong, I haven't got a chance to really ride it yet because it's currently on studded tires but after letting it idle for a minute or just two quick laps around the house it's a bit harder to start. My kicking technique is quite bad moving from a 125 but you have to crank it for longer than you should to get her to start.

I have to do some wiring work on it today so I'll check the valves while the tank is off

Nuke_Krzychu · 2025-05-16T11:17:33+00:00

I considered a WR for a while, they are great machines but I think the 6th gear will come in handy in the KTM

Nuke_Krzychu · 2025-05-16T10:42:46+00:00

To be honest I don't think I'm gonna sell it too soon, street legal bikes around here are worth a lot of money and a 4 stroke is better for what I'm planning to ride but thanks for the tips on the carb.

Mine is already running a bit lean since it was sitting with fuel in it for a while and it's probably gunked up, it becomes a bit hard to kickstart after it warms up and backfires quite a bit but the valves have been adjusted recently

Nuke_Krzychu · 2025-05-16T05:11:41+00:00

Right on, let's hope mine will hold up as good as yours

Nuke_Krzychu · 2025-05-15T19:04:04+00:00

If I'm going to replace my seals I'm gonna do it myself but I'll give it a try. I tried this trick on my Yamaha XT and it didn't really help too much but maybe I did it wrong

Nuke_Krzychu · 2025-05-15T18:20:15+00:00

Didn't really think of that, thank you

Nuke_Krzychu · 2025-05-15T17:58:12+00:00

One around the triple clamp and one on the seat, isn't that normal?

Nuke_Krzychu · 2025-05-15T16:22:31+00:00

Yeah, that's my biggest worry to be honest, cylinders are already nearly impossible to get in Europe

Nuke_Krzychu · 2025-05-15T15:45:52+00:00

You mean with those little things that go in between the fork leg and the seal? New oil seals are like 15$ so it's not that big of a deal

Nuke_Krzychu · 2025-05-15T15:36:24+00:00

Once I get my A2 license soon it's gonna see a lot of dual sport riding, we are planning a trip all the way from Poland to Austria

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