Cold Start Gremlin!

[ac427]

I have a 2002 M3 manual
according to RealOEM, it's up to 09/2004 for manual vehicle.

https://www.realoem.com/bmw/enUS/showparts?id=BL93-USA-11-2001-E46-BMW-M3&diagId=11_2996

Regarding the vacuum line to FPR, yes I will be replacing with brand new silicone hose. The existing BMW design has a barb and a small U-shape tube that always fell off and ended up dangled or lost.

Thanks, I just don't think the diagram is right for my 09/2003 Convertible.

I've got an actual picture on my phone but do you think i can get it to upload. I'll have a go when I get back.

[Edit]

[bmwfnatic]

There’s no connection to the dipstick, there’s a male bung threaded into the oil pan.

[ac427]

There’s no connection to the dipstick, there’s a male bung threaded into the oil pan.

Thanks Mate. Is there a check valve in the line?

[ethan]

Thanks Mate. Is there a check valve in the line?

Yeah, otherwise your crankcase wouldn't be forced to vent through the cyclone separator up top.

[ATB88]

FYI the part you guys are talking about is different for factory manual cars vs SMG/converted cars. I can't remember all of the details but I remember back when I was replacing that hose after I did my manual conversion it was confusing. The version of that hose for manual cars won't work for SMG and vice versa, I think the brackets/receiving ends/plumbing are a little different in either case, I think to account for getting around the SMG pump.

[ac427]

FYI the part you guys are talking about is different for factory manual cars vs SMG/converted cars. I can't remember all of the details but I remember back when I was replacing that hose after I did my manual conversion it was confusing. The version of that hose for manual cars won't work for SMG and vice versa, I think the brackets/receiving ends/plumbing are a little different in either case, I think to account for getting around the SMG pump.

Thanks very much.

So is that the SMG hose in the picture in post number 40 ?

[ATB88]

Thanks very much.

So is that the SMG hose in the picture in post number 40 ?

I *think* so.

EDIT: wait no. realoem says that that's the one for manual transmissions, see part number on this diagram: https://www.realoem.com/bmw/enUS/sho...diagId=11_2996

the diagram is a little misleading about how the pipes look, google the part number 11617831930

contrast with the one that realoem says is for SMG, on this diagram: https://www.realoem.com/bmw/enUS/sho...diagId=11_2999 , part number 11617831336

I think the 6MT one has that extra thing built into it whereas the SMG one doesn't. I think that whatever the function of that extra bulge on the 6MT part is, is taken care of in the rest of the different plumbing that the SMG hose plugs into?

[ac427]

How important is vacuum on when running CSL software in your DME?

The brake servo/booster obviously needs vacuum but apart form that?

[Slideways]

None of the RealOEM diagrams show the correct non-CSL E46 M3 dipstick.

The SMG crankcase vent hose is shorter (and takes a different route) than the manual version due to the SMG pump being between the intake manifold and oil pan.

I thought that was a drain for the airbox, but the description for that part is "crankcase breather hose". Someone might need to verify this, but I believe it takes the positive crankcase pressure and draws it up into the intake.

If you want to know how the rest of the PCV system works for the early and later cars, there is a good discussion in this thread - https://nam3forum.com/forums/forum/m...her-tube/page2

[y2k_o__o]

There’s no connection to the dipstick, there’s a male bung threaded into the oil pan.

My bad, I have never taken this apart in the past when I clean the throttle body, so I assumed that REALOEM has provided a correct diagram.

Do you have any picture of the male bung in the oil pan? I will be replacing all those hoses in X'mas time

[y2k_o__o]

Thanks Mate. Is there a check valve in the line?

Yes it does. The check valve allows the oil return to oil pan, but doesn't allow the air being sucked during vacuum.

[ethan]

Yes it does. The check valve allows the oil return to oil pan, but doesn't allow the air being sucked during vacuum.

Did you check this on the new factory tube you just bought? I've asserted this for a while, but want someone else who has known-good OE hardware to confirm it since I made my own hose.

[bmwfnatic]

Do you have any picture of the male bung in the oil pan? I will be replacing all those hoses in X'mas time

There is the bung, it has a few inches of small pipe attached to the bottom of it, you can screw it out and clean it out to make sure it's not blocked.
There's a 16x12x1.5mm aluminium crush washer below it (not sold separately but just use a generic one) and they seem to be torqued to around 18nm from factory.

EDIT: Here is a picture of the actual part removed.

[ac427]

There is the bung, it has a few inches of small pipe attached to the bottom of it, you can screw it out and clean it out to make sure it's not blocked.
There's a 16x12x1.5mm aluminium crush washer below it (not sold separately but just use a generic one) and they seem to be torqued to around 18nm from factory.

EDIT: Here is a picture of the actual part removed.

Thanks for the info. Where does the other end of that pipe go to?

[bmwfnatic]

Thanks for the info. Where does the other end of that pipe go to?

Well, I think the point of it is that it is supposed to be “under water” aka under the oil level, hence the dipstick tube is used for this on the M54. So that whatever is draining through it is not fighting against possible positive crankcase pressure.