Oil dipstick o-ring - can't refit dipstick tube!
Oil dipstick o-ring - can't refit dipstick tube!
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daniel-5zjw7

Original Poster:

648 posts

132 months

Thursday 27th December 2018
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Hi all,

I've been carrying out CCV replacement on my E46 over the last couple of days, all has been going well and I'm coming to the final stages of putting it back together when I've hit a problem with what I thought was going to be a non issue.. that is refitting the dipstick tube. Oddly since removing the dipstick tube I haven't been able to find the old o ring, it wasn't on the dipstick tube or in the sump hole. No matter as I got a new one from BMW anyway. Problem is, no matter how I do it, either by putting the o ring on the the tube and pressing/applying downward force or seating the seal in the sump hole first and then trying to push the dipstick tube through, i cannot get it to fit back in.

The groove the o ring sits in starts off with slightly tapered walls, then goes straight for a few mm before tapering again but this time its rounded to allow the seal to sit in there. It doesn't help that the tapered straight sections have plenty of crud from 15 years which is tricky to clean as any dirt falls straight into the sump. At the moment I can't even get the o ring into the tapered section! I've tried lubricating the seal but that hasn't helped.

My thoughts are now either to use temperature to try to help and freeze the seal, Or perhaps trying a slightly thinner walled seal, the BMW one is 19.5 x 3 but I could try a 19.5 x 2.5.. I get the seal needs to fit very tightly but the standard one seems crazy.

Does anyone have any experience with this/can share how they did it? Or even any ideas/tricks there are for o rings I can try? Fairly desperate as expected to have the car running again today..

dmarkovina

639 posts

114 months

Thursday 27th December 2018
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I would try the suggestion in the very last post:

http://forum.bmw5.co.uk/topic/90366-struggling-to-...

Good luck.

helix402

7,913 posts

213 months

Friday 28th December 2018
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Grease sump entry hole, grease tube, grease o-ring. (Ideally silicon grease, any old grease will do despite it allegedly making rubber fall apart).

bmwmike

8,772 posts

139 months

Friday 28th December 2018
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I remember struggling with this on my m52tu engine, I don't think I ever got it in fully but managed to get it tight enough that it didn't leak significantly. I don't think it sits below the oil level.

daniel-5zjw7

Original Poster:

648 posts

132 months

Saturday 29th December 2018
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Hi guys,

Just to report back as did get this done.. I ended up cleaning the dipstick hole as best as I could using brake cleaner on a microfiber cloth, I read that to help shrink/resize an o-ring (I'd had a number of attempts at fitting getting the seal covered in oil in the process) to stick it in hot water, so I did this and then re-greased in silicone grease and tried again with the o-ring on the tube and in the dipstick hole.. still no joy!! So I switched to washing up liquid on the centre of the o-ring and on the dipstick tube and seated the o-ring first, after a little firm persuasion the tube went through.

Its looking good so far and no leaks, it was leaking previously so hopefully that's problem solved.

For anyone reading this doing their CCV, pay attention to this element, its trickier than any other part of this job!

Regarding the oil not reaching the o-ring I'm not exactly sure on my oil level prior to doing this job, but think it was around the 3/4 mark, and the oil was only about a cm below the o-ring seat, so it wouldn't surprise me if it does on full..

Sardonicus

19,461 posts

252 months

Sunday 30th December 2018
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Done more than a few CCV hose kits/sets on the M54 engined E46 (all gen BMW parts) and never had this issue would of only used red rubber grease or similar on the dipstick steel tube scratchchin we live and learn I guess