Low oil pressure - AAZ

[Gizmoman]

Big bummer.
I have been taking the van to work (56 miles round trip) to shake it out/break in the engine after a complete rebuild.
I have over 1500 miles on it now (dino oil) and the blow-by has subsided to near zero - that's the good news.

A few days ago after a hard run on the freeway at 35-3600 RPMs/70-75 MPH, my oil pressure dropped to zero at a light. Freaked me out and I slid my foot to the pedal and raised the R's to make some pressure.

A short dive to the house and I shut it down. When I would start it in the morning, it used to make 70-80 psi, now it's more like 55 psi (cold). Oil level is at the top of the upper line on the stick so low oil is not the issue.
I believe it's time to switch to full synthetic (Rotella T-6 5-40) and will be doing so before I drive it again (new filter as well).

There is a very thin oil film on the belt side of the engine that could be the IM shaft seal but it doesn't seem serious. I pulled the cover and checked timing belt tension as a loose belt would possibly indicate a bad IM shaft bearing, but it feels exactly like it was when I first installed it. BTW, the IM shaft has ball bearings so if they were "out" the belt would be quite loose)
As youy can see in the photo, I cross-drilled a hole to bring oil into the front side of the dual ball bearings. This hole should have been smaller but my running pressure used to be a bit higher than it is now.

Also, there is no oil whatsoever in the turbo (compressor side). and none on the exhaust side. The oil pump is a new unit, "Febi" is the manufacturer if I recall. Oil pressure is taken at a "T" at the turbo line from the top of the filter mount. The filter itself has been relocated and I am running a cooler and fan so high oil temps are not a problem.

When the pressure drops, the engine doesn't sound different so it seems my lifters are staying pumped up but I have to say, I am beginning to think the oil pressure (when warm) may be too low across the board - 30-35 PSI at 3400! If I really push it hard, I get a "valve float" type of flutter at high RPM's (close to 4K). I thought it may be my lift pump causing a fuel restriction as I had been leaving it turned off. After turning it on, the issue didn't go away. Could low oil pressure keep my valves from opening at high RPM's?

The biggest bummer is the wife and I have long been planning a three week road trip in early September, camping and kayaking. This issue could put a real damper on that

There are any number of things that could cause this, but I'd like to get other opinions and where I should begin to look for issues.

Jim

[srgtlord]

Is it possible that too much oil is some how leaking through the arrangement of ball bearings?

[vanbcguy]

What's the story with your oil pump? Where is it from originally, how old is it, etc?

[Gizmoman]

What's the story with your oil pump? Where is it from originally, how old is it, etc?

I know my post is "wordy" but I do mention that it's new and a Febi brand. I'll also add that it is the correct one for an AAZ with the wider gears and longer pick-up tube.

Is it possible that too much oil is some how leaking through the arrangement of ball bearings?

It is possible but the pressure has dropped about 20 psi since the first start after the rebuild. I don't know when it went South, but it used to be higher.

Keep the suggestions coming (reasonable ones only please). I won't be able to get "into it" till the weekend buty every idea keeps the brain cells clicking away!

[libbydiesel]

I'll also add that it is the correct one for an AAZ with the wider gears and longer pick-up tube.

Whadaya mean it is the correct one for an AAZ with the longer pickup tube.  It has a diesel vanagon oil pump pickup tube on it, doesn't it?

[Gizmoman]

Well, what I should have said is "it's the same one that came off the original engine (vanagon) and was recommended by libby" (except for the brand)

The pickup tube sits about 1/4" or less from the horizontal surface of the 50 degree AAZ vanagon style pan.

I did have the pan off a while ago to do some tig welding. I also removed the pump (don't recall why). Maybe I didn't torque the two bolts enough and it's leaking at the seat.

[libbydiesel]

The oil pump not being torqued properly is a scary thought.  I asked on your mirrored thread whether or not the idiot light came on when the gauge went to zero.

[Gizmoman]

The oil pump not being torqued properly is a scary thought.  I asked on your mirrored thread whether or not the idiot light came on when the gauge went to zero.

It didn't that I noticed and it does work AFAIK. Light comes on with key and shuts off soon after start.

I'm fairly sure I put blue locktite on the two bolts and torqued to the spec - but I'm not 100% sure of it. That's an excellent application for safety wire - just thinking about being loose it makes me wince. That's the trouble with us weekend mechanics - never do enough of the same thing to form good, specific habits (no excuse though).

I'll drop by AutoZone tomorrow after work and get a new sender (Auto Meter), a long grease gun hose, and remote mount it.
Man, I hope that's it

[745 turbogreasel]

Have you changed the oil?

Cut the filter open  with a knife or  pipe cutter(not a sawblade), and see what you find in there.

[Gizmoman]

I was planning to any way because it's due. 1st one was after 200 miles, and it's getting Rotella T6 5-40 synthetic.
Opening up the filter is a great idea but I don't have a pipe cutter that big.

Hopefully the FLAPS has a new sender with two posts.


The gauge and sender are Glowshift. - not the best but I like them.

[Gizmoman]

No such luck finding a new sensor locally - I have one on the way.
In the meantime, I rigged up a gauge (tested accurate).

Here's a shot of it idling - not quite warmed up all the way


I'm stoked. Once it warmed up idling pressure was a tad over 30 psi.
Goes up to 60+ when I punch the throttle.

Sweet!

[libbydiesel]

Right on.

[ORCoaster]

Always pays to have that mechanical backup you know you can trust doesn't it.

[Gizmoman]

Good communication can be so cool

Thanks everyone

[92EcoDiesel Jetta]

Is that a 300 psi gauge?  Boudon tube gauges are most accurate at the middle of scale, not at extreme ends. I'd suggest getting a 0- 20 psi gauge and plumb it in when engine is hot (so you don't pin it from cold starting) to confirm you are really getting 10 psi hot idle.