AAZ engine oil pressure

[wolf_walker]

I had a TD installed in the 81 Caddy that came out of an 85 Jetta, that was in an 81 Jetta, and finally ended up in the 82 Caddy.
But anyway, it was the most worn out VW-D I've ever seen that still ran more or less correctly.
Exactly 1.2psi of 15w40 at the flange, hot, at idle.  Bout 25 on the road steady.  Less with hard use/high oil temps.
Ran it for it's last 15K miles that way.  Improperly rebuilt head and worn IMS bearings from too-snug belt was most of
it's problem.  And age.
It made it to 400K though, last drive east to west with it was 37MPG@75mph with the AC on.  Used a quart of oil every 500 miles,
if you poured it in to quickly it made a funny glug glug glug noise when it first started up afterwards.  Valve guides had
HUGE amounts of play.  It still ran OK.  Ahh, the memories and miles.
I can't remember if Father rebuilt that one or if it's in the trunk of a Volvo in the woods back east still.

[damac]

do 1.6 and aaz run at same oil pressures?

i got what i would call a healthy running motor that came in my 79 rabbit but i can tell something isn't right.  15/40 oil here

it was some supposed vw rebuild that didn't see many miles, it has some vw sticker on it.  it is doing the job except what i would call oil pressure issue compared to other used engines i have run.

im going to install an auber electric gage this week but mine is reading about 10 at hot idle and i cruise at 40 when going 70mph, and those numbers are at the head.

i put in a high flow oil pump and replaced the intermediate bearings when i had the engine on the stand and there was no real world difference in readings from before and after?


im going to put my gage on the flange but have a feeling it will be close to spec if thats 29 @ 1900 rpm.

would you use that as the magic number before tearing into things or just run it as long as its spec?

i also replaced the oil pump shaft bushing in the block and put a new seal in the vacuum pump.

if the im bearings are fresh what step of the line would be causing the lower oil pressure?

[air-cooled or diesel]

doing the mains will boost pressure at flange, the im bearings wont improve oil pressure much.
i know the bentley has the oil pressure sensor minimum in it, rough guesstimate head oil pressure of ~7 psi at hot idle is getting too low. i cannt say for sure at flange, and flange is the best reading point.

[wolf_walker]

Any excess clearance can cause low oil pressure, the IM bearings are common since people over-tighten the belt.

I don't have any books on the AAZ that I know of, no idea on the oil pressure spec.
One might look at the diff between spec for the 1.6D and an old 1.7 or 1.8L gasser and see how that ratio looks,
then extrapolate something with specs for an ABA 2L gasser.  Or one might find the spec in a book for a Canadian car
but that's no fun.

I don't think your numbers are any concern, I'm 22ish idle and 60ish at speed at the flange I noted yesterday, 140K or so
on Rotty-T 15/40 every 5K since new fwiw.  I don't remember what it was like out of the crate, and it's sans-turbo now.
Many people teach that idle PSI is of little importance as long as there is some, and it jumps up to 20 or 30 when
RPM rises.  I wouldn't sweat yours if it starts up when it's cold and isn't consuming a ton of oil.

What brand oil pump did you use?  Note that in many cases though possibly not VW-D as I've never seen a worn pump
personally, high volume does not mean high pressure.  There's a pretty old debate about such things. 

[theman53]

doing the mains will boost pressure at flange, the im bearings wont improve oil pressure much.
i know the bentley has the oil pressure sensor minimum in it, rough guesstimate head oil pressure of ~7 psi at hot idle is getting too low. i cannt say for sure at flange, and flange is the best reading point.

This is as far off of a good comment as possible. The head is the best spot to take a reading as it is the last place to get oiled and the first to lose pressure when a problem persists.
IIRC bentley spec is 18psi at 2,800RPM at the flange for oil pressure. I am not for sure on that as I did it by memory but I know they do not have an idle spec.

The IM shaft bearings are crucial to oil pressure. Maybe the most crucial. They are like a cam bearing down there and when overtightened they flake away, leaving a giant gap for oil to leak out of. 10x that of a main or rod bearing. When you lose pressure there then it loses more pressure further up into the head.

If the crank is older and has been polished it could have too much clearance to yeild better numbers than what you have. Also if someone rebuilt it and didn't seal the squirters it could be leaking off pressure there.

[wolf_walker]

I haven't pulled as many apart as some of you guys, but even not well cared for examples that I have, I haven't seen much in the way of wear
other than on the IMS bearings, presumably from belt tension error.  The bottom is really robust on these things within the bounds of
mostly stock.  Heads wear out, rings break, cylinders scuff, but the crank and rods are pretty solid if they are even vaguely cared for in my
experience.  Except for those damn IMS bearings.

[Blue Haze]

wolf walker, I kinda sick about the whole thing.  I'm going to call the vendor where I got the motor but it is past the 90 day warranty period.  I did chg oil to rotella 15-40 today looks like the pressure may have came up 5# at most.  12-15# at idle something like 27-30# at 2000 rpm and about 35# at 2700 or 70 mph.   

[wolf_walker]

If you paid a ton for it especially, I'd ***, but I'd have the book-spec in hand to quote before ***ing,
and if they have a decent Better Biz Bureau rating, tell you will be filing a complaint if they don't step up.
I'd call em too, but if they say tuff *** I don't think I'd loose too much sleep over it.  Try and be cool about it
though.