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Klifex Oil Filter Housing Anti-Drainback Valve

414 Views 16 Replies 4 Participants Last post by  325TI_Compact
I had on-going P0011 issues. At some point, I realized it was the anti-drainback valve allowing the OFH to drain, which in turn led to low oil pressure on startup to the VANOS. Symptoms were the red oil light stayed on for a few seconds on each start (like a normal car would, after an oil change) and freeze frame of the P0011 showed it triggered at or right after startup.

Normally, one would just change to a new housing and change it again, when it fails. I am cheap and decided to try the anti-drainback valve replacement. I bought mine off ebay, from the Ukraine, for $30 shipped. Yes, the same one that is at war with Russia, but it still arrived in 9 days. It comes with a new OFH gasket also.

No instructions come with it in the box, but ebay listing (and the link above) showed a picture of using pliers to pull out the old unit, then installing the new unit, after lapping the plunger to seal surface. You reuse the spring from the original drainback valve. It's a really tight fit, so I ended up drilling sections of the original valve, until the rest of the old valve fell out. Original valve, mangled, but out of the housing:

Here you can see the grooves that the stock plunger eventually grinds into the housing, which is one of several reasons why it was no longer functioning:

The other issue with the stock design is that the plunger is too short. The Klifex design has a longer plunger which goes into a guide hole, keeping the plunger from dropping back in off-axis, when oil pressure is absent. Additionally, the replacement has wider plunger fins to spread the abrasive force of the plunger, as well as a better sealing surface shape.

If I remember. I'll report back on how well it's holding up.
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Fascinating. Never heard of/seen this solution before.

I wonder if there's any particular cause for the drain valve wearing, or if it's just inevitable
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For those interested, I removed my OFH this morning. Lots of stuff was out due to me changing the hard coolant pipes under the intake manifold, so I thought I'd remove the OFH and take a look.

Very interesting. It had a good sized groove in the valve housing like in the photos previously posted, but it was not aligned perfectly with one of the valve blades that causes the problem. I've changed the OFH gasket a few times in the life of the car, and clearly when I had the OFH off in the past I had played with the valve, and unintentionally rotated it a small amount. Only about 10 deg. It was now grinding a new groove in the location of where the blade was now. It was barely visible, but clearly it was starting the groove grinding process again.

So what is the solution? When you remove the OFH, push in the valve and rotate it so the blades are not aligned with the groove. Have a look at the photo I posted on page 1 of this thread. This is how I would make it look. Obviously this needs to be done as preventative maintenance. If the valve is leaking like RayLivingston's, it's all too late and a new valve/OFH is required.

I own two E46 330s, and the OFH will be coming off the other very soon to adjust the valve.
Saw this post

Very, very interesting. Wish I knew this back when I did my OFHG.
Can you clarify if you mean the slots in the housing or the plastic? From my reading, I'd seen various depths of grooves in the housing. I assumed it was from varied amounts of wear.
Ah sorry, here's a link to the thread for context

No those slots are to keep valve from rotating and guidance.
I can make some prictures from my car oil filter housing.

Or have a search for some pictures...
Here you can see one of the slots.
What are the purposes of the slots then, why does it matter if the valve can rotate?
The valve
Yup that is why confused, when I bought new housing years ago.
Brought it back to dealer and replacement has the same grooves.
How deep are the grooves? Maybe the valve is tested from factory, or caused by the assembly process
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