I have about 1000 miles on my freshly rebuilt 1911 engine. I added a VDO Oil Pressure gauge and sensor using an 18" or 20" long paint ball gun hose. I mounted the sending unit on a small DIY "L" bracket on top of the fan housing.
Click to view attachment
I am curious what I should be seeing for oil pressure.
Recently: Engine warm, CHT at 340F, Oil temp reading above 100, I see the oil press gauge dropping very low, maybe below 10 during acceleration prior to shifting at 3000 to 3500rpm. At a level RPM when cruising OP is 20 to 30. At idle, it is higher, maybe 40.
This is the 1st time I remember seeing the OP drop that much during acceleration.
Is is normal to see a pressure drop during acceleration? Didn't I read that that is how these AC vw engines run? Is the pressure fluctuation I am seeing normal?
Thanks,
Clark
Full Version: VDO oil pressure gauge
What oil are you running and is it at the full mark?
What about the windage tray?
You may be sucking air if the oil is sloshing away from the pickup, or if the windage tray is keeping oil from returning from the heads.
What about the windage tray?
You may be sucking air if the oil is sloshing away from the pickup, or if the windage tray is keeping oil from returning from the heads.
QUOTE(malcolm2 @ Jan 7 2014, 09:14 PM) 
I have about 1000 miles on my freshly rebuilt 1911 engine. I added a VDO Oil Pressure gauge and sensor using an 18" or 20" long paint ball gun hose. I mounted the sending unit on a small DIY "L" bracket on top of the fan housing.
Click to view attachment
I am curious what I should be seeing for oil pressure.
Recently: Engine warm, CHT at 340F, Oil temp reading above 100, I see the oil press gauge dropping very low, maybe below 10 during acceleration prior to shifting at 3000 to 3500rpm. At a level RPM when cruising OP is 20 to 30. At idle, it is higher, maybe 40.
This is the 1st time I remember seeing the OP drop that much during acceleration.
Is is normal to see a pressure drop during acceleration? Didn't I read that that is how these AC vw engines run? Is the pressure fluctuation I am seeing normal?
Thanks,
Wow ! I hope your gauge is somehow wired backwards. Pressure is normally lower at idle and increases with RPM. Rule of thumb is approximately 10psi per 1000 rpm.
Clark
QUOTE(McMark @ Jan 7 2014, 11:28 PM)
What oil are you running and is it at the full mark?
What about the windage tray?
You may be sucking air if the oil is sloshing away from the pickup, or if the windage tray is keeping oil from returning from the heads.
Brad Penn 20 W 50. Just ran about 500 miles on it, After changing the break in oil. I checked the oil last week and it was actually maybe a 1/4 qt over filled. I remember being careful to put 3.7 qts in and it still came out extra full.
What is the question on the windage tray...? I did re-install it during the rebuild, re-used the orange seals.
Dr. 914 suggested that I put a temp. mechanical gauge on to compare. I'll see if Auto-zone rents one. Tractor supply has some oil filled ones with 1/4" threads for @ $8. So I'll have to find some fittings to match.
Did you line bore the case when you built it?
At operating temp I'm running slightly above 20psi at idle and around 55psi on the freeway. My engine has a little over 2,000 miles on it after a full rebuild. Brad Penn 20/50 oil.
Though running a 2056 I'd expect similar values to your 1911. Warmed up idle is around 8-10 PSI, cruising at 3,000-3,300 RPM pressure is around 35-38 PSI, do not see a drop during acceleration nor have I ever experienced such with any car, nor have I seen higher pressure at idle than cruise. Agree that your values sound backwards.
Is the sending unit well grounded, normaly the stainless hose provised a ground but with the rubber hose you need to make sure the sending unit case is grounded.
sounds more like wiring problem, crossed wires at gage mabe. (seems to be reading bakwards)
I have the same type of setup and I read ~10-15 at oil temp 200deg and Idol and ~35-40 at 3000 RPMs.
My motor has about 52,000 miles on it.
sounds more like wiring problem, crossed wires at gage mabe. (seems to be reading bakwards)
I have the same type of setup and I read ~10-15 at oil temp 200deg and Idol and ~35-40 at 3000 RPMs.
My motor has about 52,000 miles on it.
Thanks all. It is warming up to the 40's over the next day or 2. So I will drive the car again and verify my numbers and the gauge operation. Along with some sort of mechanical gauge closer to the port.
The pressure numbers should go up with RPM (until it gets high enough that the relief valve opens), and should go down with warmer oil temps.
The behavior you are seeing is NOT normal. Re-confirm with a mechanical gauge; your gauge and sender may not be "talking" the same electrically.
If your oil pressure is really doing this, you need to stop driving and start disassembling things to figure out what is wrong. Driving with very low oil pressure like that will wear out everything that can wear, pretty quickly. It could also lead to more catastrophic issues--and that engine looks far too clean to require extra holes punched through it by a thrown rod...
--DD
The behavior you are seeing is NOT normal. Re-confirm with a mechanical gauge; your gauge and sender may not be "talking" the same electrically.
If your oil pressure is really doing this, you need to stop driving and start disassembling things to figure out what is wrong. Driving with very low oil pressure like that will wear out everything that can wear, pretty quickly. It could also lead to more catastrophic issues--and that engine looks far too clean to require extra holes punched through it by a thrown rod...
--DD
Crossed wires . Swap the temp wire with the pressure.
QUOTE(Dave_Darling @ Jan 8 2014, 09:57 AM)
The behavior you are seeing is NOT normal. Re-confirm with a mechanical gauge; your gauge and sender may not be "talking" the same electrically.
If your oil pressure is really doing this, you need to stop driving and start disassembling things to figure out what is wrong. Driving with very low oil pressure like that will wear out everything that can wear, pretty quickly.
--DD
My "glass half empty" mentality is making me think the worst. I have seen statements on the forums about the 10 PSI per 1000 RPM, but I also vaguely remember seeing that fluctuations happen while driving, oil sloshing around etc...
I've read several posts about track cars taking turns and having idiot lights flicker kinda things.
Being that I have not had this car on a track or at track speeds or turns is a worry. The half full side is hoping for a gauge issue and will check everything possible.
I'll start the car tonight and video the gauge, might have a mechanical one in place too.
What you are experiencing is exactly why I did this:
And my mech gauge and VDO agreed almost perfectly.
I will remove the mech gauge before any serious driving.
And my mech gauge and VDO agreed almost perfectly.
I will remove the mech gauge before any serious driving.
QUOTE(stugray @ Jan 8 2014, 12:19 PM)
What you are experiencing is exactly why I did this:
And my mech gauge and VDO agreed almost perfectly.
I will remove the mech gauge before any serious driving.
That looks like the Tractor Supply or Northern Tool gauge I found last night.
Is it? I like the set up, you might not have to remove the gauge...very nice.
They were $6 to $15 and I could get today. Another website had them with the proper threads, TSC and NT was a 1/4" npt, i need 1/8" or some fittings.
It is a pressure gauge for an accusump. I think I paid $40 at Summit or pegasus.
With some new info for the VERY LOW pressure. Turns out the signal wire on the sender was loose. So I tightened it up and shot this video. I should have commentated, but anyway 1 of 2 shows the gauges with KEY off, then on, then start and some revving, but mostly cold. I had to shoot 2 videos, 2 of 2 is with the CHT at normal 340-ish. Oil temp never moved.
I end up with over 50 psi at idle and it drops to 20 at 3200. so the very low condition was fixed by tightening the wire.
Take a look and please comment.
pre-start and cold running:
https://www.youtube.com/watch?v=5PsTowPa2cw
warm engine:
https://www.youtube.com/watch?v=UjZGrtzlS7Q
I was able to purchase a mechanical gauge (gauge from TSC: 1/4" npt, 1/4 to 1/8 stuff at HD) and fittings to attach to the paint ball hose, so I might work on that tonight. but the comparison will be forthcoming.
Clark
I still suspect a problem with the gauge. It should have lower pressure at lower RPMs, and higher pressure at higher RPMs. Yours is backwards, which either shows something very funky going on inside the motor (oil pressure control pistons? bearing clearances? other?) or a gauge issue.
--DD
--DD
The way your pressure gauge pegged high, even before the engine was on makes me feel like it's operating exactly backwards of how it should. I can't think of a mechanical way that this would occur.
Check your wiring.
Check your wiring.
QUOTE(Dave_Darling @ Jan 9 2014, 08:06 PM)
I still suspect a problem with the gauge. It should have lower pressure at lower RPMs, and higher pressure at higher RPMs. Yours is backwards, which either shows something very funky going on inside the motor (oil pressure control pistons? bearing clearances? other?) or a gauge issue.
--DD
It should build pressure, not lose it. Did you check the ground for the sender yet? Very important to get the right signal.
your "hot" and signal wires might be reversed. try swapping the wires on the + and s terminals and see if it acts normal then.
QUOTE(rmdinmd @ Jan 9 2014, 07:28 PM)
your "hot" and signal wires might be reversed. try swapping the wires on the + and s terminals and see if it acts normal then.
I double checked that before the video.... Originally I made a mini wire harness or all 4 gauges... Hot to hot to hot, etc... Same for the illumination lights. From the rheostat to each bulb and a ground wire to each bulb.
But I did do it... wire on + to S and wire on S to + and the gauge does not move at all.
Did anyone notice when I turned the key on, the pressure gauge went to max. Is that normal?
QUOTE(malcolm2 @ Jan 9 2014, 08:53 PM)
Did anyone notice when I turned the key on, the pressure gauge went to max. Is that normal?
No. Check your ground.
The oil pressure gauge must be grounded also, most VDO gauges require 3 connections 12 volts, ground and sender connection.
QUOTE(ThePaintedMan @ Jan 9 2014, 07:23 PM)
QUOTE(Dave_Darling @ Jan 9 2014, 08:06 PM)
I still suspect a problem with the gauge. It should have lower pressure at lower RPMs, and higher pressure at higher RPMs. Yours is backwards, which either shows something very funky going on inside the motor (oil pressure control pistons? bearing clearances? other?) or a gauge issue.
--DD
It should build pressure, not lose it. Did you check the ground for the sender yet? Very important to get the right signal.yes, I did check that too. Continuity to the - post of the battery anywhere on the braided hose, the sender or the hose clamp holding the sender to the fan and from the fan.
QUOTE(ThePaintedMan @ Jan 9 2014, 07:55 PM)
QUOTE(malcolm2 @ Jan 9 2014, 08:53 PM)
Did anyone notice when I turned the key on, the pressure gauge went to max. Is that normal?
No. Check your ground.
The ground on the gauge?
The gage has 3 wires and 2 wires for the light.
Pin+ to 12v
pin- to ground
Pin S to sensor
On the sensor there are 2 terminals one is for the oil light (labled wk) the other is for the gage.
What model of gage do you have, and which sensor do you have?
Pin+ to 12v
pin- to ground
Pin S to sensor
On the sensor there are 2 terminals one is for the oil light (labled wk) the other is for the gage.
What model of gage do you have, and which sensor do you have?
QUOTE(malcolm2 @ Jan 10 2014, 11:53 AM)
QUOTE(rmdinmd @ Jan 9 2014, 07:28 PM)
your "hot" and signal wires might be reversed. try swapping the wires on the + and s terminals and see if it acts normal then.
I double checked that before the video.... Originally I made a mini wire harness or all 4 gauges... Hot to hot to hot, etc... Same for the illumination lights. From the rheostat to each bulb and a ground wire to each bulb.
But I did do it... wire on + to S and wire on S to + and the gauge does not move at all.
Did anyone notice when I turned the key on, the pressure gauge went to max. Is that normal?
You could have sticking pressure regulating valve pistons from pump and main oil gallery.
QUOTE(somd914 @ Jan 8 2014, 02:58 AM)
Though running a 2056 I'd expect similar values to your 1911. Warmed up idle is around 8-10 PSI, cruising at 3,000-3,300 RPM pressure is around 35-38 PSI, do not see a drop during acceleration nor have I ever experienced such with any car, nor have I seen higher pressure at idle than cruise. Agree that your values sound backwards.
What i see exactly. Also 2056.
Try the following test, Measure the voltage from the +12 battery to the oil pressure
gauge case. It should stay at 12 volts if it changes the ground is missing to the gauge
case. Other wise you may have the wrong combo of sender and gauge.
gauge case. It should stay at 12 volts if it changes the ground is missing to the gauge
case. Other wise you may have the wrong combo of sender and gauge.
QUOTE(gunny @ Jan 9 2014, 08:20 PM)
The gage has 3 wires and 2 wires for the light.
Pin+ to 12v
pin- to ground
Pin S to sensor
On the sensor there are 2 terminals one is for the oil light (labled wk) the other is for the gage.
What model of gage do you have, and which sensor do you have?
Yes the wiring is correct. the 12v and the ground go to each gauge that needs it and the S pin wire goes back to the sender.
I should check to see if there are physical #s on each, but the invoice says they are both the 0-80 devices. 360-006 for the sender and 350-105 for the gauge.
Besides the actual part #s, I feel good about wiring and grounds at this point. only thing left to do is to add the mechanical gauge.
After looking at your video it looks like you have the terminals reversed on the sending unit. To test connect one side of a light bulb to battery and the other to
one of the post on the oil pressure sender, the light should light bright with the engine off, if it is dim try the other connection on the sender and see if its bright
thats the oil light side ,then the other should be the gauge.
Disconnect the wires to he sender first.
Check 360-006 sending unit markings WK=warning light, G=gauge
one of the post on the oil pressure sender, the light should light bright with the engine off, if it is dim try the other connection on the sender and see if its bright
thats the oil light side ,then the other should be the gauge.
Disconnect the wires to he sender first.
Check 360-006 sending unit markings WK=warning light, G=gauge
QUOTE(904svo @ Jan 9 2014, 09:25 PM)
After looking at your video it looks like you have the terminals reversed on the sending unit. To test connect one side of a light bulb to battery and the other to
one of the post on the oil pressure sender, the light should light bright with the engine off, if it is dim try the other connection on the sender and see if its bright
thats the oil light side ,then the other should be the gauge.
Disconnect the wires to he sender first.
it would have to be labelled incorrectly for me to have it connected incorrectly. Could that happen? I marked the factory stamps for the WK and G with a sharpie.
I vaguely remember trying to switch them months ago and something crazy happened, like the idiot lite stayed on.
I now know that this is a gauge or sender or maybe wire problem, but I am 99% sure that the wires are, at the very least, connected correctly.
Check out the latest video.... check your volume, I do commentate on this one, and tried to talk over the engine, sorry.
25psi at idle... 55psi at 3000rpm. thank the lord.... I was not going to open this thing up AGAIN!
https://www.youtube.com/watch?v=Y2TOgFibQ1g
WOW, no leaks either...YET
"I got a gauge problem."
Yes, you do. But not an engine problem--WHEW!!
Try this as a double-check: Run a wire from the housing of the sender to a ground like the crankcase.
I believe that the sender is a variable resistor. Check the resistance from the terminal on the sender to ground at idle and at 3K RPM. I think the resistance goes down as the pressure goes up? Then check the resistance for the same conditions on the sender wire at the gauge.
You might just have the wrong gauge for the sender/the wrong sender for the gauge.
--DD
Yes, you do. But not an engine problem--WHEW!!
Try this as a double-check: Run a wire from the housing of the sender to a ground like the crankcase.
I believe that the sender is a variable resistor. Check the resistance from the terminal on the sender to ground at idle and at 3K RPM. I think the resistance goes down as the pressure goes up? Then check the resistance for the same conditions on the sender wire at the gauge.
You might just have the wrong gauge for the sender/the wrong sender for the gauge.
--DD
QUOTE(Dave_Darling @ Jan 10 2014, 01:19 AM)
"I got a gauge problem."
Yes, you do. But not an engine problem--WHEW!!
Try this as a double-check: Run a wire from the housing of the sender to a ground like the crankcase.
I believe that the sender is a variable resistor. Check the resistance from the terminal on the sender to ground at idle and at 3K RPM. I think the resistance goes down as the pressure goes up? Then check the resistance for the same conditions on the sender wire at the gauge.
You might just have the wrong gauge for the sender/the wrong sender for the gauge.
--DD
Best I can tell, the sender only has a few markings and they are on the flats of the hose connector. I did see "0 - 5 bar" and "0.5 to 0.015" on 2 flats. I assume that is the range and the tolerance.
5 bar is about 73 psi, and I have a 0 - 80 gauge. Is that how they are matched up?
I'll check the resistance this afternoon, thanks for the suggestion.
Clark
VDO 360-006 has a risatance range of 10-480 ohms and is 5 bar sender (0-80 psi)
Well, I spent some time back and forth online with a VDO support guy today. So all this crap was caused by some jack-leg selling me a mis-matched gauge and sender. The sender is rated 10 to 180 ohms, and the gauge is looking for 240 to 33 ohms. notice the way the rating is stated. one goes up, one goes down.
My gauge going down and showing lower pressure, cause it is the 240/33 gauge and the sender is sending 10/180. BACKWARDS.
It makes perfect sense to use matched pairs, but can anyone tell my why are the ohm rating is NOT LISTED with the gauges? You just have to know what to buy or sell? This is the real kicker. How do you know???
So now I know I need a 350-104 gauge to go with my 360-006 sender.
thanks to everyone for their input, Once again, I have soaked in some knowledge. And if nothing else, I got to practice embedding videos.
Clark
My gauge going down and showing lower pressure, cause it is the 240/33 gauge and the sender is sending 10/180. BACKWARDS.
It makes perfect sense to use matched pairs, but can anyone tell my why are the ohm rating is NOT LISTED with the gauges? You just have to know what to buy or sell? This is the real kicker. How do you know???
So now I know I need a 350-104 gauge to go with my 360-006 sender.
thanks to everyone for their input, Once again, I have soaked in some knowledge. And if nothing else, I got to practice embedding videos.
Clark
QUOTE(malcolm2 @ Jan 10 2014, 03:15 PM)
Well, I spent some time back and forth online with a VDO support guy today. So all this crap was caused by some jack-leg selling me a mis-matched gauge and sender. The sender is rated 10 to 180 ohms, and the gauge is looking for 240 to 33 ohms. notice the way the rating is stated. one goes up, one goes down.
My gauge going down and showing lower pressure, cause it is the 240/33 gauge and the sender is sending 10/180. BACKWARDS.
It makes perfect sense to use matched pairs, but can anyone tell my why are the ohm rating is NOT LISTED with the gauges? You just have to know what to buy or sell? This is the real kicker. How do you know???
So now I know I need a 350-104 gauge to go with my 360-006 sender.
thanks to everyone for their input, Once again, I have soaked in some knowledge. And if nothing else, I got to practice embedding videos.
Clark
Glad that's all it is ! Bad on the salesman for selling you a missmatched set.
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