Rebuilt engine low oil pressure

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sgnimj96
Turbo Charger
Posts: 259
Joined: Thu Feb 20, 2014 2:08 pm

Rebuilt engine low oil pressure

Post by sgnimj96 »

I picked up a "rebuilt" 12mm engine to swap for my problematic 11mm engine.
It was a roll of the dice and a lot of work to save some money
and now that it's running - the oil pressure sucks.
It's like 20psi@1000rpm COLD. 50psi max revving it up COLD. I imagine fully heated up would idle near zero.

I don't think the vacuum pump could be the issue because it's off the old engine that had good oil pressure.
I also tried another vacuum pump, same oil pressure.

I tried different oil pumps, same low pressure.

Put a mechanical gauge on the oil filter flange, it reads the same as
the mechanical gauge at the head.

The intermediate shaft was hard to turn by hand when I first checked it, it got a little easier with some lubing.
Visual inspection of the outer IM shaft bearing seemed ok but I don't know much about them other than the
holes need to line up. I figured the "reputable rebuilder" did them correctly and that tight fit must be a good thing.
Now I'm dreading that the inner one was done wrong and I'm back to zero.

The only thing left I can think to try is swapping in the IM shaft from the 11mm engine.
I've read those threads about replacing IM bearings - special tools and pro skills
Is there anything else I can try?
81' Scirocco 1.6D (conversion)
86 Golf 1.6D
85' 300TD
Fatmobile
Global Moderator
Posts: 7564
Joined: Wed Oct 30, 2002 10:28 pm
Location: north central Iowa

Re: Rebuilt engine low oil pressure

Post by Fatmobile »

20psi at 1000 is pretty good.
I would be happy with that.
I ran one that was at about 7 warm in the VNT-15 for a long time.
Seems like that happened in about every engine I used clevite I-shaft bearing in.
I use sealed power now.

As far as changing I-shaft bearings goes,
the engine needs to be out of the car.
Or I've heard of people lowering that end of the engine enough to do it.
When I tried that the alternator hit the lower rad hose sooo,..

An old I-shaft works great as a special tool.
I grind down the thrust surface until it will just fit through the hole, a little smaller than the outer bearing.
I wrap the seal surface with masking tape until it's big enough to hold the inner bearing tight.
Slide the inner bearing onto the taped area and run it down into place.
The outside of the thrust area drives it into place.
The oil filter mount needs to be removed so you can look through the hole and line up the oil hole.
And the vacuum pump gets removed to reach a finger in and guide the shaft.
If you get it wrong, shove it through and try again.

Now put the outer bearing on the shaft up against the thrust surface,
where it normally rides.
Sliding the shaft through the inner bearing makes sure it's lined up straight.
Removing the gear lessens the damage it could do to the new inner bearing.
Tap the outer bearing into place.
Since there is no thrust surface to stop you from going too far
I stop and use a flat washer to set it flush with the block.

I thought I had a picture of my "special tool" but looks like I'll have to take one.
It so works amazingly well, that when finished I stand there with hands on hips and say,
"Well look what I have done, that went so smooth and didn't take long at all, what a great tool, everyone should have 1".
'91 Golf gasser converted to a 12mm pump, M-TDI.
'84 1.6TD Rabbit with a VNT-15 turbo, still setup to run on vegetable oil.
'84 GTI with 1.7TD pistons and intercooled.
2003 TDI wagon
2000 TDI Jetta.
sgnimj96
Turbo Charger
Posts: 259
Joined: Thu Feb 20, 2014 2:08 pm

Re: Rebuilt engine low oil pressure

Post by sgnimj96 »

This is good stuff. Still trying to wrap head around that, but
to keep moving I did the IM shaft swap from the 11mm block.
The one I took out didn't look as smooth on the inner surface.

Measurements with the HF digital caliper comparing the 2 were
kinda too close to call; anyway, swapped in the other IM
shaft, got it back together.

It was late, but I fired it up and the oil pressure was a little better!
I'll give it another go tomorrow, got an appt at the dmv
in the morning to put a plate on it.

All the while I'm messing around with this
I'm supposed to be breaking the rings in
on this engine!
81' Scirocco 1.6D (conversion)
86 Golf 1.6D
85' 300TD
Fatmobile
Global Moderator
Posts: 7564
Joined: Wed Oct 30, 2002 10:28 pm
Location: north central Iowa

Re: Rebuilt engine low oil pressure

Post by Fatmobile »

So the engine is out and on a stand?
'91 Golf gasser converted to a 12mm pump, M-TDI.
'84 1.6TD Rabbit with a VNT-15 turbo, still setup to run on vegetable oil.
'84 GTI with 1.7TD pistons and intercooled.
2003 TDI wagon
2000 TDI Jetta.
sgnimj96
Turbo Charger
Posts: 259
Joined: Thu Feb 20, 2014 2:08 pm

Re: Rebuilt engine low oil pressure

Post by sgnimj96 »

No, the 12mm engine is in the car.
Removed the mount bolts and lowered it down
enough to get the IM shaft out.

I don't even have a stand (or a hoist). :roll:
81' Scirocco 1.6D (conversion)
86 Golf 1.6D
85' 300TD
sgnimj96
Turbo Charger
Posts: 259
Joined: Thu Feb 20, 2014 2:08 pm

odd readings

Post by sgnimj96 »

When I had both oil gauges hooked up, seems strange they read the same (at the same time)
Most people say that the pressure at the oil filter flange would be much higher than at the head.

It looks like the oil pressure at idle still stays around 10 but the pressures at speed are not
near as good as they should be for a mechanical head. It seems odd the idle pressure would
be that good.

One thing I noticed when spinning the oil pump with drill to prime the system,
is that I could hardly see the oil coming up in the head, no idea what it normally
looks like; But I could definately feel the load on the cordless drill from the pump.

Its a CY block, so it has the squirters, but I don't know how to check those.
I'm running it NA.

This engine has VERY little blowby. I still have the pvc hose "T" that connects the crankcase outlet and the
valve cover outlet and back to the intake. I did notice, when I took the valve cover off,
there was absolutely no oil residue in the intake like the old 11mm engine would have, which was nice.
Here's a dumb question - Could the pvc suction effect on the crankcase actually lower
the oil pressure readings at high rpm?
81' Scirocco 1.6D (conversion)
86 Golf 1.6D
85' 300TD
sgnimj96
Turbo Charger
Posts: 259
Joined: Thu Feb 20, 2014 2:08 pm

Re: Rebuilt engine low oil pressure

Post by sgnimj96 »

Well I crimped off the pcv hose coming from the crankcase and
that has no effect on the oil pressure, lol.

I have no tach so, using this site http://www.scirocco.org/gears/
it looks like I get about 10-12 psi per 1000 rpm when fully heated up (15w40).

Took it for a short drive with both gauges hooked up.
Pressures run exactly the same at the filter and the head.
I was really hoping the filter would read at least a little more.
81' Scirocco 1.6D (conversion)
86 Golf 1.6D
85' 300TD
Fatmobile
Global Moderator
Posts: 7564
Joined: Wed Oct 30, 2002 10:28 pm
Location: north central Iowa

Re: Rebuilt engine low oil pressure

Post by Fatmobile »

Good.
10 to 12 at idle is plenty.

So you had the valve cover off while turning the oil pump with a drill?
And saw no oil coming from the cam?
That's a good thing, it's a pretty good test for if the cam journals are loose.
I had a loose cam in a rebuilt engine and the oil poured out around the cam journals when I did that test.
I took the head back to the place that bent it straight and was supposed to line bore it,
they lined bored it to spec and no oil came out from around the cam, when the pump was turned with a drill,..
and oil pressure came back up to normal.

Having the same pressure at the head and filter is a good thing I would think.
It means there is no big gap the oil is leaking from between the filter and head.

Did you plastigauge the cam journals?
'91 Golf gasser converted to a 12mm pump, M-TDI.
'84 1.6TD Rabbit with a VNT-15 turbo, still setup to run on vegetable oil.
'84 GTI with 1.7TD pistons and intercooled.
2003 TDI wagon
2000 TDI Jetta.
sgnimj96
Turbo Charger
Posts: 259
Joined: Thu Feb 20, 2014 2:08 pm

Re: Rebuilt engine low oil pressure

Post by sgnimj96 »

Not having any engine building experience, I didn't check anything
involving plastigauge or micrometers . Just ASSumed that this longblock
was done and went straight into the install (Doh!!!) . Reminds of the saying,
"hurry up and fuckup". :lol:

The 10-12 psi I get at hot idle is also with the idle turned up a bit.
So that's not great.

In my younger days I drove a couple vw diesels for years, long trips, clueless,
no real gauges. Changed oil, fixed a few basic parts, didn't even know
how to time them. I know there are thousands of these old engines
running with no oil pressure gauges, like the engineers really didn't
think people should worry about it.

I've come a long way, but this is obviously a major piece of
the puzzle. An engine stand may be in the near future.
Cool thing is this is a 12mm turbo block w/ arp main and head studs.

I did just order the tiny 068145117B seals that go in the vacuum pump.
Both of my vacuum pumps still have the old black seals. Man, those things are a
pia to source, $17 to order at my local dealer, so I scrounged online and found some at
a dealer in NY for $6. https://parts.teddyvolkswagen.com/produ ... t=53861039
Called them up to check and they had 3 at their local warehouse
Got 3 on the way for 27 including shippin. (I have 3 of those vane pumps)
81' Scirocco 1.6D (conversion)
86 Golf 1.6D
85' 300TD
Fatmobile
Global Moderator
Posts: 7564
Joined: Wed Oct 30, 2002 10:28 pm
Location: north central Iowa

Re: Rebuilt engine low oil pressure

Post by Fatmobile »

Yeah, the dealership is the only place I've found those vacuum pump seals.
And they do want quite a bit for them.
My local dealership gives me about a 15% discount.

My buddy wants to sell me a '85 Golf for maybe $400.
It's not in nice shape but has the 12mm block, manual steering rack and the much coveted rectangular headlight grill and rad support.
Has about 235,000 miles on it.

Scrap prices are getting high.
We are going to be losing a bunch of these to the crusher.
I spent the last 3 days pulling parts off a couple MK4 wagons.
Windshields are such a pain to pull on those.
Hell just getting the windshield wipers off takes a special tool,... and a hammer.
'91 Golf gasser converted to a 12mm pump, M-TDI.
'84 1.6TD Rabbit with a VNT-15 turbo, still setup to run on vegetable oil.
'84 GTI with 1.7TD pistons and intercooled.
2003 TDI wagon
2000 TDI Jetta.
sgnimj96
Turbo Charger
Posts: 259
Joined: Thu Feb 20, 2014 2:08 pm

Re: Rebuilt engine low oil pressure

Post by sgnimj96 »

Those are some great endeavors.
Mk2 golfs have gotten rare now. Someone did a recent thread about that on vortex.
IMO should have never stopped making mk2 golfs and mk4 wagons! (lol)
With the idi and mtdi diesel power plants, those platforms became the last of best
for people that want the "luxury" to really own their vehicle.
The typical used car today is just an engineering mess (and everybody knows it).

Just saw my neighbors 20 y/o minivan get towed off yesterday.
I was going to change out a bad axle for her, but then she decided to
wait (budget issues). Squirted some grease in the torn boot and
told her it would still drive like that for a while.
So... something else must have gone wrong for it get towed. Looks like she did the right thing.
That axle was super cheap on rockauto, but she still balked on it because, money.
I'd be surprised if that thing ever comes back.
81' Scirocco 1.6D (conversion)
86 Golf 1.6D
85' 300TD
Fatmobile
Global Moderator
Posts: 7564
Joined: Wed Oct 30, 2002 10:28 pm
Location: north central Iowa

Re: Rebuilt engine low oil pressure

Post by Fatmobile »

So did you get new pistons or is this a rering?

The more I think of it,.. I should try to see if I can save the '85 MK2.

It's too bad folks are afraid to work on their own cars.
I know a few girls that have been brave enough to turn some wrenches.
An axle swap probably wouldn't have been that hard for her after watching a utube video.
I try to teach the neighbor kids to use wrenches.
The metrics and fractions are good for them to learn.
We usually start on bikes.
Small town kids get sooo bored.

Nice of you to help her extend the life of the axle.

I was so mousey smelling after parting those cars.
Got some strange looks at the store, stranger than usual I should say.
All clothes went right in the laundry and I showered before sitting down in the house.
The seats and interior I grabbed are sitting in the rain, wind and sunshine for a few days/weeks,
and will get sprayed with a hydrogen peroxide, baking soda, dish soap mix.
'91 Golf gasser converted to a 12mm pump, M-TDI.
'84 1.6TD Rabbit with a VNT-15 turbo, still setup to run on vegetable oil.
'84 GTI with 1.7TD pistons and intercooled.
2003 TDI wagon
2000 TDI Jetta.
sgnimj96
Turbo Charger
Posts: 259
Joined: Thu Feb 20, 2014 2:08 pm

Re: Rebuilt engine low oil pressure

Post by sgnimj96 »

It's tough having to mess with older cars, but being able to legally use the older engines and gearboxes
is gold is this crazy car-world we live in.
And yea, shredder scrap is going for .10/lb here. Bad news for old cars, bad sign for the Dollar.

That engine is said to be bored .30 over and have forged pistons.
Kinda an injustice to be running it N/A but that was the nearest deal available
and it sounded like it would really hold up, ha.
Could be worse, I basically half-assed it by just swapping parts, putting a clutch on
and running it.

Hoping the green seal for the vacuum pump gives me an little boost in oil pressure,
81' Scirocco 1.6D (conversion)
86 Golf 1.6D
85' 300TD
Fatmobile
Global Moderator
Posts: 7564
Joined: Wed Oct 30, 2002 10:28 pm
Location: north central Iowa

Re: Rebuilt engine low oil pressure

Post by Fatmobile »

I just looked at your list of cars.
This is going in the '86 Golf right?

You have an '81 Scirocco?
Noice.

Right the price of metal going up is a bad sign of future inflation.
Because that's the raw materials needed to make things.

Was just looking at clearance stuff.
An upper rad hose for the MK2 diesel,.. $21
https://www.fcpeuro.com/products/vw-rad ... 121101akmy
Someone was looking for one, was it you?
Pretty good price.
'91 Golf gasser converted to a 12mm pump, M-TDI.
'84 1.6TD Rabbit with a VNT-15 turbo, still setup to run on vegetable oil.
'84 GTI with 1.7TD pistons and intercooled.
2003 TDI wagon
2000 TDI Jetta.
sgnimj96
Turbo Charger
Posts: 259
Joined: Thu Feb 20, 2014 2:08 pm

Re: Rebuilt engine low oil pressure

Post by sgnimj96 »

This is for the scirocco. I wouldn't say it's a nice looking car. No a/c and a bit
clunky but it's pleasant in other ways. No strange smells of decomposing plastics,
everything is pretty much fossilized.

The 86 golf isn't plated, just stored in the back waiting :roll:
Thanks for the deal link, but that weird stock rad hose creeped
me out a long time ago so I bought a new radiator (for like $50) that uses
a regular upper hose and has a separate overflow line to the reservoir.
Did that with the a/c and p/s delete.
Oddly, that mk2 non-a/c upper hose also fits as the upper rad hose
in my 300TD.

I get the feeling that having lots of (drivable) vehicles is not going to be so easy
in the future. The dmv seems to be getting really unfriendly about plates and tags,
pushing people away from doing tag transactions in person.
Saw them turning a lot of people away last time I went, forcing them to
some counter to make appointments (that sometimes take a week).
Thing is, for what I was doing, there is no "plate swapping" request online.
I had to call and get an "emergency" appointment to be able to get in there.

Last time I called to ask for and "emergency" appointment
some irritated lady told me what I was doing
has to be done by MAIL, which is ridiculous.
It's probably better where you are at.
All this crap started with the covid bs, but now that it's over
the dmv looks like it's unfriendly protocols are never-ending.
Every time I go there is some new rule (and new employees).

What it really does is put even more pressure on people to
keep working transportation so they don't have to deal the dmv.
81' Scirocco 1.6D (conversion)
86 Golf 1.6D
85' 300TD
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