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Old 04-06-2018, 08:06 AM   #21
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Any other vdo guys have this issue?
No, not at all. My VDO oil pressure gauge's needle swings with rpm changes quite readily, seemingly as it should. In fact, you could use mine as a crude sort of tach.

The gauge needle will obviously respond as directed by the sending unit. What sender are you using?

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Old 04-06-2018, 08:28 AM   #22
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vdo 360-028
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Old 04-06-2018, 09:05 AM   #23
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vdo 360-028
Huh. That's the same sending unit that I have used on several different cars, and it is the correct 0-80 psi sending unit which matches the gauge. So no clues there.

Upon a cold start, my idle pressure's pretty high, as one would expect. Once warmed and at idle, the pressure is corresponding low, again as one would anticipate. And when running thru the gears, the needle swings left to right as a function of rpm, just like you'd think it oughta do.

So I guess that I am out of possible answers now!

Thanks - DM
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Old 04-06-2018, 09:10 AM   #24
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running 5w50 i see about 70lbs of cold oil pressure at idle, dropping down to about 10-12psi hot idle. While the gauge does swing as you get on it, its not as instant as one would expect, making it hard to check, especially while tracking. Where did you run your ground? Perhaps I need to upgrade my ground location
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Old 04-06-2018, 09:34 AM   #25
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Originally Posted by Dave80GTSi View Post
Huh. That's the same sending unit that I have used on several different cars, and it is the correct 0-80 psi sending unit which matches the gauge. So no clues there.

Upon a cold start, my idle pressure's pretty high, as one would expect. Once warmed and at idle, the pressure is corresponding low, again as one would anticipate. And when running thru the gears, the needle swings left to right as a function of rpm, just like you'd think it oughta do.

So I guess that I am out of possible answers now!

Thanks - DM
Same setup for me too. I run M1 15W50 and see 80+ psi cold, 15-17 psi after a session (hot ~ 220F). I have tons of live data on this on my youtube videos. From 3,000 RPM up to 7,000 when oil is hot, pressure hovers around 40-45 psi. Oil pressure gauge definitely moves instantaneously. My oil temp location is on the bank 2 valve cover rear.

All my wiring and gauge connections are behind where my cup holder was and I used the console metal frame for a good ground. Works fine for me. Your oil temps seem slightly high considering it was cold. I will see maybe 225F with 85-90F air temps, but I do have a 2 qt Accusump.



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Old 04-06-2018, 09:37 AM   #26
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Where did you run your ground?
I think i grounded mine under one of the bolts that was under where the front of the shifter is. I think... I may have grounded it to the ground wire of the phone plug, which is where I got my wire... I can't remember

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So gauges were not a distraction at all and line of sight was fine. It was cold out so oil temp only got to 235. Pressure seemed consistently low, but the gauge seems to move kinda slow so it was hard to tell. Any other vdo guys have this issue?
My vdo gauge (I have the VDO 350-104) with that same sender and I run 10W50 oil.

Here are the things I have observed:
  • At cold - the gauge goes to around 70 (essentially pegged) regardless of RPM
  • At normal highway driving, oil around 190-200F it is around 55-60 and stays up there as long as I have some revs up. At idle it drops to around 20 (ok let me find some of my videos to verify, when I was running other oils, the oil would go lower than 20 at hot track level idle)
  • On track, if I got up to around 235F oil temperature, it would max out around 45'ish PSI. Note that the oil pressure read at this location is around 10 PSI lower than the oil pressure at the crank and down near the oi pump (See AZ986S video where he displays two oil pressures - the one read from this spot and the one read on his accusump). The hotter the oil, the lower max PSI readings I have observed.
  • The oi pressure does respond to RPM, but it is like if the needle were in some molasses. Easiest to see whe the oil is around 190-200F (normal driving). Go to idle, the oil pressure falls down shortly after. Rev it up, the oil pressure will rev up, again slightly delaying.

Here are a few laps from Sebring about a year ago, at the beginning of the video the oil temp is 205'ish and by the end, the oil pressure is getting close to 240F

First lap in video:
End of front straight:
RPM: 6250'ish
Oil temp:205'ish
Oil pressure:50

Going down the back straight, 2:21 into video
RPM: 6250'ish
Oil temp: has now climbed to 220F
Oil pressure: 45'ish

2nd and last lap in the video
End of front straight: 2:55 in video
RPM: 6500'ish
Oil temp: 225'ish
Oil pressure: 42.5'ish (1/4 of way between 40 and 50)

Back straight 5:10 in video
RPM: 6000
Oil temp: Almost up to 240F
Oil pressure: 40

This was on 5W40 - it is better on 10W50 for me, but it is still the nature of the beast with these engines...

How does this compare to how your oil pressure gauge was reading?

https://youtu.be/0Od4GJDpvDc



Here's another Sebring, Nov 2017, with the gauges visible - you have to maximize the video in HD and squint, but it is there This is with 10W50 and it is a "little" better... These laps around around 6-7 seconds faster than the other ones from above

https://youtu.be/4DTCPJizquo

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Old 04-06-2018, 10:17 AM   #27
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hmm. From those videos, my gauge definitely feels like its moving more slowly. If I run it up to rpm quickly in a lower gear, it takes a bit for it to catch up, and that doesn't seem to be the case for you guys.

I followed the instructions to a T (16 gauge wire to sender, 14g ground) and a fused power source. The only thing I didn't do is use a dedicated ground, so I'll have to check on that.

I have oil temp on the drivers side, oil pressure on the passengers as I'd assume you guys do also.

My car has always run hot and I'm not sure why, but its also a base car with a 3.2, so maybe a bit less cooling capacity.

Can someone postulate as to what the unmarked lines on the gauges indicate. The one after 200 seems like 210 to me (what my car runs on the street), then 240?
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Old 04-06-2018, 11:00 AM   #28
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Originally Posted by Quadcammer View Post

Can someone postulate as to what the unmarked lines on the gauges indicate. The one after 200 seems like 210 to me (what my car runs on the street), then 240?
From measuring with my durametric:
The two that are to the left of the 200F are 170F and 190F. I was expecting a linear progression from the 120F mark to the left past the two evenly spaced ticks on the way to 200F, but they measured out as 170 and 190, then verified with 200 when I got to that level.

I have been treating the two on the right as 220F and 240F but when I was street driving with the durametric the time I did the calibrations I never got it hot enough to verify anything over 200F. And the two ticks to the left of 200F are not linear, so who knows

But if you look at this other VDO gauge that runs off the same sender (and this is an interesting thread as well)

https://rennlist.com/forums/996-forum/827720-oil-temp-gauge-using-the-built-in-oil-temp-sensor.html

https://www.vdo-gauges.com/instruments-displays-and-clusters/by-series/cockpit/cockpit-300-deg-f-oil-temperature-gauge-use-with-vdo-sender.html

The 180 and 220 marks on this cockpit gauge seem to match our VDO Vision Black gauges:
The 180 seems to split the two lines that I marked as 170 and 190 -Edit: i just figured out to overlay the graphics, the 180F lines up with the 2nd line that I was calling 190F.
The 220 seems to line right up on the line I am calling 220



I have never gotten to the 220F on the street, the only time I get over 200F on regular street driving is if I get jammed up in traffic and not getting good airflow. On the highway it is 200F and below.

I also have a 180F low temp thermostat.

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Old 04-06-2018, 12:08 PM   #29
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hmm. From those videos, my gauge definitely feels like its moving more slowly. If I run it up to rpm quickly in a lower gear, it takes a bit for it to catch up, and that doesn't seem to be the case for you guys.

I followed the instructions to a T (16 gauge wire to sender, 14g ground) and a fused power source. The only thing I didn't do is use a dedicated ground, so I'll have to check on that.

I have oil temp on the drivers side, oil pressure on the passengers as I'd assume you guys do also.

My car has always run hot and I'm not sure why, but its also a base car with a 3.2, so maybe a bit less cooling capacity.

Can someone postulate as to what the unmarked lines on the gauges indicate. The one after 200 seems like 210 to me (what my car runs on the street), then 240?
What sender are you using? I grounded mine at the ground in the auxiliary plug. I just tapped power and ground into that plug. It would be VERY cool to be able to find the male side of that particular plug and make a custom harness.

I used the 996 sender. My gauge operates similarly to the others, almost like a tach. If you used the 996 sender, is it possible you swapped the leads? Not sure if that would make a difference or not, but maybe?
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Old 04-06-2018, 12:24 PM   #30
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using a 2 pole vdo sender, same as most everyone. The other pole is an on/off switch, so I don't think thats possible.

I'll take a short video over the weekend.
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Old 04-06-2018, 12:26 PM   #31
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...The only thing I didn't do is use a dedicated ground, so I'll have to check on that.
I don't see how it could make a difference, but they specifically call that out in the instructions for the gauges if I recall. Might be worth a try...

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I just tapped power and ground into that plug. It would be VERY cool to be able to find the male side of that particular plug and make a custom harness.
That would be very cool!

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I used the 996 sender. My gauge operates similarly to the others, almost like a tach. If you used the 996 sender, is it possible you swapped the leads? Not sure if that would make a difference or not, but maybe?
He's got the VDO sender that is the non-porsche branded version of the (presumably) same part. If the leads were swapped (and I think the blades might even be two different sizes) it would not work at all, the one is simply a low pressure switch that (presumably) completes a circuit to ground when the pressure drops below a certain level.

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