oil pressure light

[fast_hatch]

so ya, i've recently been getting the oil light coming on and beeping and blinking and goes away, everytime it happened was always below 2000rpm,mostly like 1300-1500 rpm, oil level is fine, just changed with elf 5w-40 like 800 miles ago. the po always changed the oil and always used sythedic(sp?) the car has 64,000 and i'm leaning to the oil pressure switch but the problem is, i can't seem to get to the switch and can't seem to find it.... all help is appreciated!  i don't know what to do.   car makes no strange noises and it ALWAYS happens below 2000 rpm..

[Jeronkie]

I hope you’re talking about a 1.8t  The pressure switch you will under the intake mani ,just above the oil filter ,and is only connected to one wire ,,,,I would  take out the sensor and connect it to a manual pressure gauge to see if the pressure is still in spec , before replacing it ,

[olliebgollie]

so ya, i've recently been getting the oil light coming on and beeping and blinking and goes away, everytime it happened was always below 2000rpm,mostly like 1300-1500 rpm, oil level is fine, just changed with elf 5w-40 like 800 miles ago. the po always changed the oil and always used sythedic(sp?) the car has 64,000 and i'm leaning to the oil pressure switch but the problem is, i can't seem to get to the switch and can't seem to find it.... all help is appreciated!  i don't know what to do.   car makes no strange noises and it ALWAYS happens below 2000 rpm..

I too am having this problem. In addition to the above scenario, I have observed the following: 1. the engine is thoroughly warmed-up (Driven in excess of 20 min). 2. I am accelerating (slowly) on a slight upgrade and shifting through 2nd or third gear. i drive the car carefully, shift early and never accelerate agressively and maybe this is method i should be avoiding. The lights have never come on while cruising down the interstate.
initially the lights would only illuminate for a second or two. Now the lights come on and stay on until i move off of the road and shut down the engine. when i start back up the light is out and i go on may way like nothing has happened.
I just purchased the car (2000 passat 1.8T, 78,000k) and i am behind the power curve when it comes to knowing this car and its systems.  i bought it from a mechanic friend and i do known some of the history. The car was brought to this fellow because the previous owner was getting the oil pressure light. He (my mechanic friend) relaced the turbo (rebuilt), oil pump, main and connecting rod bearings, thinking this would solve the problem.
I too was thinking pressure switch (sender).
does anyone know how the oil system regulates pressure? I don't see any accumulator or pressure regulator in the guides i have. could check valves/pressure relief valves preform this function and could this be an area to explore?

[Jeronkie]

the pressure of the oil pump gets regulated by a spring and ball in the oil pump ,i have seen a few guys taking the pump out and putting a spacer (so that the spring presses harder on the ball) thus raising the pressure ,,,but bob made 716hp with standard oil pressure so i don't know if its necessary ,,i would replace the sender unit and check the wire between the sender and the ECU,lastly i would manually test the oil pressure with a test gauge just to make sure

Jeronkie

[olliebgollie]

the pressure of the oil pump gets regulated by a spring and ball in the oil pump ,i have seen a few guys taking the pump out and putting a spacer (so that the spring presses harder on the ball) thus raising the pressure ,,,but bob made 716hp with standard oil pressure so i don't know if its necessary ,,i would replace the sender unit and check the wire between the sender and the ECU,lastly i would manually test the oil pressure with a test gauge just to make sure

Jeronkie

thanks for your response. i had the volkswagen dealer in my area check the pressure and change the oil/filter. they say that the pressure is good. they also checked the sender and that too is good. i still get the warning light occasionally. the previous owner did not take care of the car and it is very possible that there is sludge. could a good flush help? one mech i know advises against the flush saying it could dislodge sludge which could accumulate at a screen at the turbo inlet and starve those bearings. another mech says that the oil that vw recommends simply is not heavy enough, and that i should
try a 10-40 or 20-50 wt. oil.
olliebgollie.

[Jeronkie]

if i may ask how did they check the pressure ,,,and what do they see as good pressure ,,and how did they check the sender ,,if the pressure is good and the sender is working the only problem could be wiring ,,think about it if the oil is not heavy enough why is the pressure good ,and if your there lots of sludge the pressure still good or so they say ,,almost all the times the oil feed for turbos comes after the oil filter so i would say use the flush,,,but open a new post and ask what do the other guys think of flush ,,,I personally use it without any problems

[fast_hatch]

problem solved..... it was the oil pressure switch. i'm suspecting thats your issue aswell. the sensor was only 8 bucks.

[olliebgollie]

if i may ask how did they check the pressure ,,,and what do they see as good pressure ,,and how did they check the sender ,,if the pressure is good and the sender is working the only problem could be wiring ,,think about it if the oil is not heavy enough why is the pressure good ,and if your there lots of sludge the pressure still good or so they say ,,almost all the times the oil feed for turbos comes after the oil filter so i would say use the flush,,,but open a new post and ask what do the other guys think of flush ,,,I personally use it without any problems

olliebgollie's gonna need a new crank shaft, anybody know where i can get a crank kit for a 1.8T?

[TommyBoyee]

On an old engine with sloppy clearances you can get low oil pressure when the engine is warm and the revs are low. By adding a friction modifier like Lucas(non synthetic) you can thicken up the oil slightly to get more pressure. On a 1.8T the pump should make enough pressure on the suggested oil to keep the light from coming on. If the light comes on there is definitely something wrong.  On my modified 1.8T the oil pressure varies from about 60 psi cold at idle to somewhere around 20 psi when warm. That is on a fresh rebuilt engine with a new oil pump and screen.

[fast_hatch]

just my luck, the light is now back, i need to change my oil in a thousand miles.... what you guys think is the issue? no, i still haven't checked oil pressure yet. the car only has 67k and has only had full synthedic oil used its whole life. i'm really sik of this damn light. its also coming on at the same rpm, always below 2000 rpm. help appreciated!

[silverado]

we bought the car with 38,000 miles and now has 43,000 it has not given us any probles until Sunday when the oil indicator lite came on and then the stop engine appeared in the panel. we changed the oil with 5/40 yesterday drove it about 10 minutes and then the lite came on again