Oil everywhere in the engine compartment...

Does anyone know where oil leaks on the pipes in my 1Z (Passat '94) might be coming from?
The pipe (I think it's for the intercooler) under the battery, for example, is particularly large!

The funny thing is that the stains aren't on lubricated parts, like the cylinder head, but rather in places where there shouldn't be any oil at all!

Sure, here's the translation:

'MFG BASTI' translates to 'Best regards, BASTI' or 'Best, BASTI' in English. It's a common German abbreviation for 'Mit freundlichen Grüßen,' which means 'With kind regards.'

You should take the opportunity to remove the hoses between the turbo and the intercooler and verschandeln them out with gasoline or something similar. While you're at it, you can also reposition the oil drain from the engine downwards, block off the EGR valve, and then you shouldn't have these problems again!
but be careful, it's illegal!!
gruzz mozz

Hi,

Oil stains on the outside of the hydraulic hoses are an indication of leaks and should be taken very seriously!

The intake air always contains a very fine oil mist (e.g., due to oil that seeps past the charger seals), which is normal. In principle, it remains within the charging system and doesn't cause any further problems. However, if the system is leaking, you'll see what you saw.

Leaks in the pressure system unnecessarily strain the charger, can lead to malfunctions, and result in reduced performance.

Depending on how severe it is, you might sometimes hear a hissing sound when the pressure builds up (that's what I heard when my coolant leak was bad).

First, visually inspect the area, then run the engine (contrary to other claims, running it in neutral is sufficient, as I could already feel the air escaping from the leak), and while doing so, check the hoses to see if you can feel any air escaping.

Otherwise, you could still print out the system, but that's more complicated (Rainer or Ulf described how to do that in the old forum).

Best regards,

Jan.

How can one examine the intercooler more closely?
The oil vapor only escapes from areas where a clamp holds the end of the pipe together.
So, could swapping the pipes potentially make a difference?

Or should I get an engine cleaning service and see exactly where the oil is coming from?

Hi Basti!

Okay, here's the translation:

'By the way, there's this round part (about 10cm in diameter) on the cylinder head, and I think it has something to do with the fuel injection pressure.' Behind this section, there's a hose leading to the low-level coolant system, which is quite pinched at this point and doesn't seem to want to straighten out.
Is this a problem, or is it not important?

Recently, I've noticed that the engine makes an extremely low and quite loud rumbling sound in the lower RPM range, and it vibrates quite a bit when I turn it off. What could that be? (Engine mount?)

Hi Basti,

What happens if you put your hand near potentially dangerous areas while the engine is running? Do you feel any escaping air?

I think it might be enough to start by checking all the fittings and connections and cleaning the pipes – perhaps that will be enough to fix the leak.

LLK: Visually inspect to see if it has come loose or detached, and otherwise, check to see if any air is escaping.

Best regards,

Jan.

Hello.

Basti911 wrote:

The oil vapor only escapes from locations where a clamp holds the end of the pipe together. Does swapping the pipes perhaps make a difference?

Use stainless steel hose clamps (because of rust), they are guaranteed to provide a tight seal.

Basti911 wrote:

Or should one have the engine cleaned and see exactly where the oil is coming from?

Good idea.

Basti911 wrote:

Also, there's this round part (about 10cm in diameter) on the cylinder head, and I think it has something to do with the injection pressures. Behind this part, there is a hose leading to the automatic transmission cooler, which is quite pinched at this point and cannot be straightened out.

Most likely the oil separator of the crankcase ventilation system; it sounds normal. Oil vapor enters the charge air system (normally) through the crankcase ventilation system.

Best regards, Rainer.

I held my hand near the leaking areas while the engine was idling, and I only felt an extremely slight air flow.
A mechanic told me that it's a normal age-related issue, and there's nothing you can do about it.

So, if it's not too bad, I'm just going to give the engine a wash now!

Could you guess where that deep humming sound might be coming from?

Thank you, Basti!

If you feel a slight air flow at idle, then at full load and 1 bar of boost pressure, it's like a hurricane! Please replace the clamps as Rainer described.

For comparison: At idle, my boost pressure is below 40 mBar according to VAGCOM, while at full load, it shoots up to about 1.2 Bar... that's a huge difference, and that's what's forcing the oil mist out.

Best regards,

Jan.

Jan6K wrote:

(contrary to other claims, the idle setting is sufficient, as mine was already noticeably blowing air from the leak) and observe the hoses, checking if you feel any air escaping.

Hi Jan,

Just because something works for your car doesn't necessarily mean it's universally applicable.

"For example, according to the LDA (Lambda-regulated air mass control), my car doesn't build up any boost pressure at all after a cold start when idling, but when it's warm, it's estimated to be around 40 mbar."

Therefore, the "blow-by" test is only reliable if an assistant properly revs the engine (approximately 2000-3000 rpm).

(For the lazy: If you spray some dish soap solution into the cooling system, bubbles might come out of leaks --> principle of the bubble blower ).
... by the way: I assume no liability for consequential damages *gg*

Hello Ulf,
The idea of using soapy water isn't bad at all. For example, it can help find small leaks in gas pipes. Of course, you just need to apply the soapy water from the outside. A leak detection spray is a bit more convenient to use (just spray it on the suspected areas). The problem is often the connection between the low-pressure line and the pressure pipe. I've also found that the best approach is to use a proper hose clamp and get rid of those quick-release clamps.

The problem with the oil isn't actually that bad...

I just gave the engine a good cleaning, and it's been relatively verschandeln for the past few months.

Lately, however, a relatively mild vibration has been occurring more frequently across almost all engine speed ranges.
However, the issues are not consistent, and no significant performance losses have been observed.
Even when idling, it occasionally makes a 'thumping' sound, and the RPM fluctuates slightly.
A deep rumble, especially noticeable from the outside, can be heard at lower engine speeds.

As I said, nothing is extremely severe, which is why I don't suspect that the needle lifter is defective. The LMM is also okay.

What could that be?

I believe that the collective expertise in this forum is certainly better than the opinion of a single mechanic who says we should wait and see, and that it's normal for a car with over 300,000 kilometers.

Thank you, CIAO BASTI!

Hello Basti,

A forum is great because you can draw on the experiences of many people.
Unfortunately, a textual description of sounds is often useless when the problem causing the sound is not immediately obvious.

My advice to you: get at least 2 more independent opinions about your problem, by having someone stand next to the car and listen (and observe).

Best regards, Rainer.