Yellow dipstick - check yours

[pudding]

So you know how supposedly the yellow dipstick is a fix for the old orange one that crumbled to bits and fell into the sump?

Turns out it isn't. I suggest keeping an eye on yours. I think I will replace it every 2 years as a yet another TFSI consumable item 

I also discovered the supplied O ring is slightly too small and causes a small vacuum leak.  I fitted a larger one and it seems to have cured some snatching/surging I was experiencing at very light throttle below 2000rpm. I'm investigating silicone O ring options as they're less prone to deterioration compared to the standard nitrile rubber o rings.

It may seem like the o ring was doing it's job going by the colour difference before and after the ring, but believe me, there was oil on top of the dipstick tube, meaning boost blew it past the ring.

The cracks you see here resulted it those bits separating and falling off with gentle pressure. They were destined to end up in the sump, so I caught it at the right time.

[stealthwolf]

@vRSAlex will probably verify I’ve had two dipstick replacements (orange and yellow). Don’t know why they crumble.

[pudding]

I've already passed this onto Alex but cheers 

They crumble because of the acidic vapours over time and they crack because of the side loadings when pulling it out/putting it in.  Plastic simply has no place being in areas subjected to fuel, oil and constant heat cycles. Probably why the MK8 has gone back to a metal sump 

If someone like Alex could come up with an ally cap with a decent sized silicon O ring, we could simply remove the dipstick completely and just pop it in occasionally to check the level.  This would completely remove the risk of bits falling into the sump.  The little guiding ball half way down the stick also falls to pieces.

I've seen the metal dipsticks from ECS tuning and Racingline, but neither of them have the tangs to latch onto the guide tube.  I don't know what kind of blow by pressure you'd need to back the dipstick out, but clearly VW thought that was a risk, hence putting said tangs on the stick.

[LC5F]

That's not ideal - I would suspect the tube is also the same material as the dipstick handle.
Likely that it will be failing too, but internally where you can't see

[ljc19630]

Thanks Kev, great info as ever!
I’d replaced mine prior to the hybrid turbo build, but will defo keep an eye on this

Cheers
Louie


Sent from my iPhone using Tapatalk

[GreigC]

Yeah… think mines seen better days…not even a seal on it! worth changing the filler neck also? Or just the dip stick?

[Lewo]

Makes note to check in the morning..... Cheers Kev.
have already broken one of the tabs.....

[pudding]

I think I'm being way too obsessive over this, but I found some suitable O-rings -  https://www.amazon.co.uk/dp/B07CVHLBYJ/ref=pe_27063361_487055811_TE_dp_1

The stock one is...



The fitted diameter of the silicon O ring is 1mm tighter on both the inner and outer diameters....



Compared to the first pic in this thread, you can clearly see the bigger o ring is going to seal a lot better! 



Probably a complete waste of time but I feel better about a tighter seal in any case, and only a few quid for an experiment 

[pudding]

Yeah… think mines seen better days…not even a seal on it! worth changing the filler neck also? Or just the dip stick?

I would change the stick and the guide tube mate    You can see in your pics that oil has made it's way out past the dipstick, so you've got a small vac leak there.  And all the missing bits are chilling out in your sump!

[GreigC]

I bought genuine dipstick and tube… I undone the tube nut looked about how to remove it and by looks of it the tube requires a bit more effort to fit so I’ll do that another time as it’s not cracked. I can tell the new dip stick has a seal it clicks into place when pushed in. (Plus the fact it has a seal) 😂

[LC5F]

Did an oil change yesterday and there definitely is a big gap around the OEM o-ring - group buy of bigger ones anyone?

Interesting that there seems to have been 3 colours of tube, my original was orange, the genuine replacement about 1.5 years ago was yellow and now there seems to be a 3rd colour of French mustard that GriegC has above, but his original looks to be the same colour.

As we are comparing dip-sticks and tubes here's mine being double yellow, being a bit camera shy:

[GilesWoodward59]

Think mine has seen better days…

Didn’t even realise it was supposed to have an o ring seal as the break is so clean!

[Dan_FR]

My yellow one lasted about 6 years of me taking it out and checking it weekly, before I noticed cracks and pieces wanting to break off. Original orange one was on 8 years, but I doubt the original owner checked it as often as I do

[pudding]

Yeah that's how long my first yellow one lasted. To be fair, £14 every couple of years is cheap insurance to stop bits falling into the sump.

Did an oil change yesterday and there definitely is a big gap around the OEM o-ring - group buy of bigger ones anyone?

Yeah I don't get that.  Maybe other engines aren't as sensitive to slight air leaks as mine, but it's definitely driving better since fitting the bigger O ring.  It's more at the lower end of the rev range, <2000rpm. It was just flat and felt like the lambda control was doing wild plus/minus adjustments, which is a strange kind of surging, almost like the handbrake is being pulled, released, pulled etc etc.

[pudding]

A few hundred miles post bigger O ring and no oil sitting on top of the tube.  I'm calling that a fix 

Out of interest, I checked the dipstick on our TDI and it's same situation. Oil misting around the dipstick area and loads of oil blown past the o-ring 

I don't know how big of a deal it really is tbh, but it seems crazy VW fitted an o-ring there that is too loose to do anything