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Author Topic: Possible cause for vanagon AAZs puking oil out the dipstick tube  (Read 1480 times)

May 01, 2018, 12:03:35 am

zuhandenheit

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I think I started a thread about this previously, but I couldn't find it, or remember if it was here or on the Samba.

In any case, if I'm right, this deserves its own thread so that it will hopefully get some visibility.

I know that this is a very common problem and I've witnessed various struggles with vans that spit out from the dipstick tube.

I'll tell my story first, but if you want my hypothesis about the cause (of which there are likely more than one), you can skip to the end.

I didn't have any trouble with the same until recently. It's happened maybe five times in the last several months, and I can't find any relevant correlated conditions that would indicate a possible cause. Once was at idle. One time it happened when I was under the van and stupidly feeling curious about the amount of pressure on my vent hose (coming out of a catch can and venting to the atmosphere), I stuck my finger on the end of the hose and immediately a great deal of oil blew out of the dipstick tube. Hah, yeah, I don't know what I was thinking would happen.

Usually it happened while I was driving and I wouldn't notice until I arrived at my destination. It was always enough to make a big mess, but never so much as to result in a measurable loss of oil.

I disconnected my catch can (which incidentally never did catch any oil) and ran the line straight out, just to see if this would help (thinking the fittings etc in the can might be creating enough of a restriction to cause the problem).This seemed to help and I went a couple weeks without incident, until yesterday.

So, yesterday I decided to make some sort of bung in my intake and run the vent line into it, hoping the vacuum would help. (It was after all designed this way!)

I had my intake apart and my aluminum intake pipe on the drill press, ready to go. But while checking over everything, I discovered a variable that did indeed coincide with the beginning of the problem.

I never removed the original AAZ dispstick tube. I could never find anything that fit very well to seal it, and had some silly little brass thing that pretty well fit in the hole, but was certainly not tight. I worried that it might fall out and get lost somewhere. So, recently, I used I guess some heave plumber's tape and fitted it really tightly. It had to be hammered into place and certainly wasn't going anyway.

Well, the original dipstick was of course not air tight! And the stock tube does not itself go down into the pan, below the level of the oil. So it can act as a vent!

I uncorked it and ran a hose to my still-disconnected catch can. Now I have an oil pan vent!

I may test it. I can attach a big hose to the Vanagon dipstick tube and then try very briefly covering the crankcase vent line. If oil does not immediately blow out of my dipstick, I'll feel confident that the problem is resolved.

Anyway, we all have different ways of handling the stock dipstick tube, and I wonder if this is a (or even THE) major reason for the differences in the occurrence of this problem.



Reply #1May 01, 2018, 10:59:19 pm

ORCoaster

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Re: Possible cause for vanagon AAZs puking oil out the dipstick tube
« Reply #1 on: May 01, 2018, 10:59:19 pm »
Connect it with clear tube and you will know when it pukes up next time.  Might even see it happen.
« Last Edit: May 07, 2018, 10:43:52 pm by ORCoaster »

Reply #2May 04, 2018, 12:16:13 am

fatmobile

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Re: Possible cause for vanagon AAZs puking oil out the dipstick tube
« Reply #2 on: May 04, 2018, 12:16:13 am »
Dipstick tube coming off the side of the oil pan style?
 Vacuum pump open/disconnected?
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with a re-ringed, '84 quantum, turbo diesel, MD block

Reply #3May 07, 2018, 01:27:46 am

bpcaddy

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Re: Possible cause for vanagon AAZs puking oil out the dipstick tube
« Reply #3 on: May 07, 2018, 01:27:46 am »
Maybe you have different dipstick resulting in to much oil in engine. I'm not sure how they account for the engine being tipped in vanagon. My aaz is in caddy and is straight up.

I think i add 1 gallon of oil and then some.

 

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