How did you all seal your dipstick housing tubes?

[mike87]

Like the title states, how did you all seal your dipstick tube housings? There's no o-ring unlike the 24V engines which the dipstick tube housing goes into the oil pan.

I'm in process of putting my M20B25 back together and, after cleaning the dipstick tube housing hole in my block, the new dipstick tube housing is very slightly loose (i.e., not a press fit into the block anymore).

Should I RTV the dipstick tube housing base and just drop it in the block hole?

[Vincenze]

There is an o-ring there.

There is no part number, though. It's about 10mm in diameter.

[mike87]

There is an o-ring there.

There is no part number, though. It's about 10mm in diameter.

Interesting, do you or anyone have a photo of this? There wasn't an o-ring when I took my original dipstick out. And like you said, there's no part # on realoem (unless I'm looking at a wrong diagram!)

https://www.realoem.com/bmw/enUS/sho...diagId=11_0548

https://www.realoem.com/bmw/enUS/sho...diagId=11_0119 (part #37 is a cover lid, not o-ring)



EDIT: Sorry to clarify, I'm not talking about the dipstick to the dipstick tube 2 o-rings at the top of the dipstick. I'm referring to the bottom of the dipstick tube (the thing the dipstick goes into), and the housing itself entirely goes into the engine block.

[Vincenze]

I wonder if the dipstick tube from the E34 is similar in diameter?

https://www.realoem.com/bmw/enUS/sho...diagId=11_1894

The diagram shows the o-ring 14,5X3

11431287541

[mike87]

I wonder if the dipstick tube from the E34 is similar in diameter?

https://www.realoem.com/bmw/enUS/sho...diagId=11_1894

The diagram shows the o-ring 14,5X3

11431287541

Unfortunately not, the E34 pan has the same setup as the 24V (M50, S50, M52, S52, etc.) pans where the dipstick guide tubes are installed into the oil pan (with an o-ring) and not the engine block (like on the M20 which I think are press-fit in).

[mike87]

bump, anybody else have a view or DIY on this?

[roguetoaster]

If you have a piece of stock of the right diameter you could expand the tube again, cool it, and put it in place. To get more extreme you could braize or JB weld it in, but most people probably just put some RTV in there.