# What does this valve in the 2.0 ABA oil filter housing do?



## OddJobb (Nov 6, 2004)

I posted thi in the MKIII forum, but I'm getting no info, so I'm re-posting here:

Anyone know what the small valve pictured next to the oil filter housing in these pictures does? This and the housing it was installed in were removed from a 2.0 ABA engine. The valve is located down inside the filter housing near the port for the high pressure oil swtich; the hole indicated by the green arrow in the first picture. The valve has a spring mechanism in it and oil flows one way only; indicated by the red arrow in the second picture. The other red arrows in indicate the flow of oil in and out of the filter housing. The port with the valve is open to the oil outflow port and high pressure switch port only; therefore it is not a bypass valve.



















I recently replaced this part on my engine. When I replaced it I installed my oil gauge sending unit onto the high pressure switch port on the filter housing since I did away with the high pressure switch to get rid of the random oil pressure false alarm issue that is common. Since relocating the oil pressure gauge sending unit to this location, I often see 0 PSI on my gauge when I start the car. After 5 to 10 minutes the gauge PSI quickly shoots up to normal PSI. I know I do not have low pressure but I wonder if this valve sticking is the source of the false pressure alarms common on these cars.


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## Anony00GT (Mar 6, 2002)

Service information simply calls it a "check valve" with no explanation.

Perhaps it's some kind of drainback valve?

I've found most false oil pressure issues to be nothing more than bad sensors though. If the valve was the problem, a mechanical gauge would reveal it.

I suspect you're not seeing pressure on a cold start because the oil is relatively thick and being dumped back into the pan by the pressure relief valve. Oil pressure specs are with an oil temp of 80*C, not cold.


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## OddJobb (Nov 6, 2004)

I think I've figured it out. I think it is a one-way valve that keeps oil in the engine block near the head when the engine is not running; at start up, oil would be ready to deliver to the valves and such instead of having to pump up from the pan, preventing premature wear and tear on these parts. I don't have the block out, nor a spare, so I cannot confirm. And you're right about the pressure problem. After thinking more about this check valve, I don't think it would prevent pressure build up of the oil in that area.


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## Jay-Bee (Sep 22, 2007)

OddJobb said:


> I think I've figured it out. I think it is a one-way valve that keeps oil in the engine block near the head when the engine is not running; at start up, oil would be ready to deliver to the valves and such instead of having to pump up from the pan, preventing premature wear and tear on these parts. I don't have the block out, nor a spare, so I cannot confirm. And you're right about the pressure problem. After thinking more about this check valve, I don't think it would prevent pressure build up of the oil in that area.


I was going to say it's something like an "oil retention valve" doing exactly as you described, to keep pressure and oil where it needs to be for cold starts.

We just had a similar discussion on Audizine about 2.0T to 1.8T oil system conversion. Some engines use the check valve in the oil filter itself, others one near the oil pump, and some like the ABA and 1.8T in the filter housing area.


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## Anony00GT (Mar 6, 2002)

Yep. Drainback valve, one-way valve, oil retention valve, all different names for the same thing


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## vdub6v (Apr 22, 2004)

Anony00GT said:


> Yep. Drainback valve, one-way valve, oil retention valve, all different names for the same thing


So this isn't a filter bypass valve?

I'm having an issue where I lose my oil prime after my ABA has been sitting for some time. I replaced the oil pump and still have this problem. Perhaps this is the issue that I am having. 

I should also mention that my ABA has a 1.8 digifant head and sits at a 50 degree angle in the back of my vanagon.


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## matty kirk (Jul 2, 2007)

vdub6v said:


> I should also mention that my ABA has a 1.8 digifant head and sits at a 50 degree angle in the back of my vanagon.]


Sick.


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## 5280 (Mar 11, 2003)

bringing this thread back from the dead, but I have info and am curious to know if it relates.

The problem stated here, where the oil prime is lost after leaving the car sitting unused is almost certainly caused by the fact it is at a 50 degree angle. I had this problem myself after leaving the car up on jackstands overnight. Not 50 degrees, maybe more like 20 or 25. But I was only able to figure out why I lost oil pressure after reading this thread that describes the same problem. Even though you're not draining the oil, my guess is the angle is enough to let air creep up and starve the check valve in the pump slowly.

https://forums.vwvortex.com/showthr...ed-oil-and-filter-no-oil-pressure-on-start-up 

Did you ever figure out this problem or does this perhaps sound like your issue?


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## vdub6v (Apr 22, 2004)

Sorry for not responding sooner, I don't look at the old Vortex the way I used to. The problem was compounded because the 1985 vanagon Bentley manual shows the wrong oil pressure sensor on the motor, I was using a higher pressure switch than what was required thus causing the delay for the oil light to turn off to be longer. I replaced the gasket and that housing with a little check valve in it and it might have made an improvement. My next step was to replace the oil pump and pickup tube and make sure the pump and pickup tube surfaces where machined smooth, I thought that maybe some mild wear on this part might add to the draining issue. Unfortunately I parked this Vanagon and because of my two children haven't had a chance to work on it. I'm hoping to get back on it in a few months and be driving it again. I will keep you posted and read that thread you reference as well. Thanks for chiming in and waking up a dead post. I hate Facebook because those posts only have relevance for 15 minutes, wish the vortex had better picture hosting and then maybe there would still be more activity out here

Sent from my SM-G930V using Tapatalk


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