Oil Leak help

[cobra]

Hi guys, I have a bunch of oil leaks on my M3 just crossing 100k miles.

1. Power steering reservoir is coated in oil - I assume it's just the o-ring on the cap.
2. Power steering pressure lines are soaked in oil but not dripping - is that worth replacing or do they all leak?
3. Right side of the engine is soaked in oil and the VANOS accumulator has drips on it - guessing it's the vanos line with a small crack or something.
4. The transmission is covered in oil on the bottom half, with some droplets forming - I am going to use some thread sealant on the drain plug and hope it goes away.

The one I am a little stuck on is the airbox. There is a small fitting on the bottom and it's leaking. Does anyone know if there's an o-ring on that fitting or I have to replace the whole connector? I am having a hard time knowing what it's even called.

Thanks

[xingster]

Check the oil filter housing gaskets also?


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[cobra]

These are some of the pics. Trans oil is clear and amber. The whole exhaust side of the motor is covered in a brown oil. CPV is totally dry. So it looks like maybe the vanos line is spraying out at some points.

[FBloggs]

Note the clean area towards the rear of the transmission?
That means the leak is large as it is flowing stronly enough to wash away any road dust/debris that would happily adhere to the oil. Minimise driving the car until the vanos line the vanos unit seals and the cpv have been deemed leak free or the source of the leak.
Once this is done, any other golden syrup colored oil may be the rear main seal so keep an eye on the underside.
The small plastic line from the intake to the sump is mostly vapor.
power steering lines/reservoir need replacing.

The positive is the active rust proofing option that is occurring for the underbody.

[Obioban]

Don't drive the car anymore until you replace at least the high pressure vanos line. Those don't last long once they start leaking, and dump a TON when they let go completely?
Which high pressure vanos line are your currently running?


Power steering reservoir has a filter in it, so it's a good 100,000 mile item even if not leaking. Lines are also due for replacement. I shimmed the power steering pump to reduce boost by 25%-- improves the steering (IMO), reduces pressure on the lines, creates less heat and HP loss. Wins all around IMO.


Pop the trans fill plug before the drain plug. If any comes out there (as in, if the level is similar to when it was filled), you're not leaking trans fluid. My guess is you're not.

[cobra]

Don't drive the car anymore until you replace at least the high pressure vanos line. Those don't last long once they start leaking, and dump a TON when they let go completely?
Which high pressure vanos line are your currently running?


Power steering reservoir has a filter in it, so it's a good 100,000 mile item even if not leaking. Lines are also due for replacement. I shimmed the power steering pump to reduce boost by 25%-- improves the steering (IMO), reduces pressure on the lines, creates less heat and HP loss. Wins all around IMO.


Pop the trans fill plug before the drain plug. If any comes out there (as in, if the level is similar to when it was filled), you're not leaking trans fluid. My guess is you're not.

I am still running the original vanos line. I really don't want to spend $150 on a OEM one... what do you think about the aftermarket options? They appear to just be a piece of brake line, but I'm wondering about the heat resistance and if they can provide the same flow rate as the original. Do the accumulators ever go bad too?

Damn, looks like I got some serious expense coming up. I'm still on the original cooling system too, but don't want to replace all that either. Damn the 100k mile mark!!

[eacmen]

Check the oil filter housing gaskets also?


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Worth checking but rarely a failure on the S54.

When I had oil on that side of the engine believe it or not but it was the front main seal.

[eacmen]

I am still running the original vanos line. I really don't want to spend $150 on a OEM one... what do you think about the aftermarket options? They appear to just be a piece of brake line, but I'm wondering about the heat resistance and if they can provide the same flow rate as the original. Do the accumulators ever go bad too?

Damn, looks like I got some serious expense coming up. I'm still on the original cooling system too, but don't want to replace all that either. Damn the 100k mile mark!!

Aftermarket lines work just fine. I’ve used the BW one and fitment was good.

However if you have a facelift model year I would personally opt for the OEM one.

[Tbonem3]

Changing the OFHG was a waste of time for me. M54 issue, not S54.

Here's a list of things that can cause oil to appear on the bottom/front of the engine.

Valve cover gasket, esp in the rear.
CPV
Vanos accumulator banjo
Chain tensioner right near the accumulator
vanos sealing plate, though that's not that much oil when the orings are dead
Oil pan gasket
I don't think I've ever seen the return line (in between cyl header pipes #4 & 5, but maybe that, esp the pre face lift cars with braided soft line and oetiker clamp

Most of this is exhaust side

There's the oil level sensor and big oil pan plug on more on the driver's side you can look at, but I don't see how that makes it to the front where the a/c is.
OFHG shouldn't be it.

In my case, it turned out to be the oil cooler lines weeping at the crimps.


Yes, replace power steering lines/res at this point. You can go OEM for the reservoir (febi iirc), but the u shaped line goes bad faster, better to get OE there from FCP as you'll likely be replacing it again. They just don't seem to last that long.

Even dirty, it's pretty easy to distinguish between ATF (PS) and engine oil. Esp our heavier oil. The ATF will be very thin. The eng oil will "stick" between your fingers more.

[lvm3sm46]

I shimmed the power steering pump to reduce boost by 25%-- improves the steering (IMO), reduces pressure on the lines, creates less heat and HP loss. Wins all around IMO.

apologies for being off topic but is there a write up on this?

[jet_dogg]

Damn, looks like I got some serious expense coming up. I'm still on the original cooling system too, but don't want to replace all that either. Damn the 100k mile mark!!

Why don't you get rid of the car if you're not willing to maintain it? It doesn't sound like you want to bother with expected upkeep.

[Obioban]

I am still running the original vanos line. I really don't want to spend $150 on a OEM one... what do you think about the aftermarket options? They appear to just be a piece of brake line, but I'm wondering about the heat resistance and if they can provide the same flow rate as the original. Do the accumulators ever go bad too?

Damn, looks like I got some serious expense coming up. I'm still on the original cooling system too, but don't want to replace all that either. Damn the 100k mile mark!!

The aftermarket ones all suggest replacing it yearly.

Get the updated OE one and be done with it.

And, yes, time to do your cooling system.

[Obioban]

apologies for being off topic but is there a write up on this?

https://nam3forum.com/forums/forum/main-forum/e46-2001-2006/189-comprehensive-steering-information-thread

[Tbonem3]

Why don't you get rid of the car if you're not willing to maintain it? It doesn't sound like you want to bother with expected upkeep.

Harsh, but true. These are old, expensive, performance machines.

[sapote]

Re to OFHG.....Worth checking but rarely a failure on the S54.

I wonder if the M3 has better gasket material than the non M cars. The housing to the block is very similar so why M3 has no issue on this.