Oil Pressure issues

[A80Avant]

i see.

does that mean that audi doesnt really care if the hot idle oil pressure sits at 1bar then?

[max_s2]

AFAIK the 1.8bar oil pressure switch kicks in when you rev over 2000rpm and have <1.8bar.

[A80Avant]

the problem is why are we seeing low oil pressure on a new engine!!!!

all bearings replaced, all clearances checked, crank in cood condition, pump in good condition... if it is not the sender unit, what could it be?

i have also noticed that the car has a 1.8bar (rs2) oil pressure switch, which i presume would notify of if the oil pressure is low. I have to see the manual about this if it exists on the rs2 dash or not. however i still see as low as 1.1bar and no warning light from the dash!

[max_s2]

Found oil pressure description on youtube. http://www.youtube.com/watch?v=8f2fc...feature=fvwrel

[max_s2]

Looks like oil pressure problems are common on these engines. Any oil pressure guru in the house?

[rs200]

what I done in 7 days:
change oil from 10w-40 to 14w-40
change 2 oil pressure sender , today I put 3. sender on it
change 2 instrument closter
change 2 oil sender (small one)
change valve under small sender (the new one)
I also clean all electrical contact on both instrument closter.

and in every case it was 1bar at hot idle

I would like to change oil pump , but they are expensive , dont want to by some rubish (China) pump. OEM audi only. .


just a second.. there was 2 type of small sensor one is for 3b,7a,nm , which have value of 0.25bar , and second is for aan ,aby,adu which have 1.7bar value .. could that make any difference on oil pressure gauge?
do you know something about that?

[A80Avant]

Can you check if the AAN pump has 2 washers on the spring rather than one which could also increase the pressure?

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[Thuppu]

I checked my aan oil pressure with a mechanical gauge and it showed about 0,5 bar more on high rpm's than the stock gauge. Idle was almost identical, maybe 0,1-0,2 bar more...

[max_s2]

A for my friends pressure problems - yep, he also checked pressure with mechanical gauge. Readings were the same as on electric gauge.

[V6quattro]

Anyone checked it with a mechanical gauge screwed in the hole for the pressure sensor?

[A80Avant]

yes, also on the previous engine rebuild as i wrote previously i had more than 2bar on warm idle, which may have been due to a pump issue with an extra washer or something that was found there and that could artificially had increased the pressure. i dont know really. My bearings were in perfect condition when removed and everything else is completely new in the engine.

Other than using a 7A head with what looks like to be identical to ADU, so no extra oil channel being open, i cannot think of anything else other than a faulty sender.

I will clean the contacts on the sender and the gauge, and get a sender replacement to see if there is going to be any improvement.

Obviously, ill check once i put the fully synthetic 10W40 what it does, but i doubt there will be much difference.

[max_s2]

what engine? What head?

Stock 3B engine with everything stock (head including).

[rs200]

Today i was doing some fueling adjustments and had the car idling for a while, as it reached 85C on vems, and the fan was kicking in, the idle pressure had dropped to 1.1bar.

Now, the oil pump was cleaned and inspected, so its surelly not that. Oil used, is mineral 15W40 for the first 1000kms break in oil.

Funnily enough, the max pressure it reaches is between 4-4.5bar so im thinking the gauge sender is going nuts.

however seeing the gauge is always worrying..

I have the same "problem" .
than I speak with friend which do motorsport engines for offroad . and he said that is full normal . he said that if oil drop under 0.8bar , and don't want to go over 4 bar over 2000rpm then it is some problem..
1 or 1.2 bar at idle it is normal.
so I don't know what to think.. I'm not smart at all.

today I replace valve under the oil pressure sensor with new one , and it is the same.. 1bar at hot idle.

A80Avant - you said that you inspect oil pump and all was ok , and you still have 1 bar at idle.. so than my pump are good to..

my mind will blow away..

[Billman]

Local forum member also has oil pressure problems. On cold engine he has 4.5bar at idle. Warm on idle shows 0.8bar, on revs it has maximum 3-3.3bar.
First he changed rod bearings as they were in bad condition. Had no changes with oil pressure.
Changed oil pump - still the readings are the same.

Ideas?

what engine? What head?

[max_s2]

Local forum member also has oil pressure problems. On cold engine he has 4.5bar at idle. Warm on idle shows 0.8bar, on revs it has maximum 3-3.3bar.
First he changed rod bearings as they were in bad condition. Had no changes with oil pressure.
Changed oil pump - still the readings are the same.

Ideas?