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914World.com _ 914World Garage _ Oil pressure concern
Posted by: 914itis Apr 23 2014, 06:27 AM
My drive to Hershey was flawless. I drive with the newly converted 6 for the first time a total of over 500 miles ov weekend.
The engine sounds great and handles great, however I have a glitch on the oil pressure gauge and light that I would like to figure it out and solved.
When the engine is cold and the car is idling at about 1200, the light is off and the pressure gauge goes up over the 3 mark, as the engine warms up it goes down to 1 at idle and will not go pass the 1 1/2 mark at any rpm as shown on the picture ;the light will come on at a full stop (1000 rpm)
I am using brad Penn 20x50 oil
I am wondering if it's the pressure sender or oil overfill.
All comments appreciated
The motor is 6yl stock 2.0
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Posted by: r_towle Apr 23 2014, 06:34 AM
Do you have an external cooler and thermostat?
Posted by: 914itis Apr 23 2014, 06:59 AM
Do you have an external cooler and thermostat?
No, just an aftermarket (PMS) tank at the factory location using AN fittings
Posted by: brant Apr 23 2014, 07:16 AM
Most likely loose tolerances (worn motor). And heats effect on the oil
Posted by: SLITS Apr 23 2014, 07:21 AM
Can't speak for the oil light, but on flat sixes up to the 3.0L, the gauge was a 10 Bar (140 psig). Using a 10 Bar sender with a 5 Bar gauge might not work really well. Maybe you have a gauge / sender mismatch.
My gauge shows 0 at hot idle, but my oil light does not come on.
Overfilling will not cause a reduction in oil pressure. It will cause oil to be blown out of the tank thru the vent.
On cold startup, my engine throws 100+ psig at 2K RPM, but then settles down to about 10 psig per 1000 RPM.
Electrical gauges are subject to 40 year old wiring connections. I would buy a cheap mechanical gauge and plumb it in to verify your gauge readings.
Posted by: 914itis Apr 23 2014, 07:41 AM
Most likely loose tolerances (worn motor). And heats effect on the oil
Oil temp looks to be ok .
Posted by: 76-914 Apr 23 2014, 09:00 AM
Most likely loose tolerances (worn motor). And heats effect on the oil
Oil temp looks to be ok .
I think Brandt meant the oil viscosity is effected by temp!
Posted by: Randal Apr 23 2014, 09:09 AM
Can't speak for the oil light, but on flat sixes up to the 3.0L, the gauge was a 10 Bar (140 psig). Using a 10 Bar sender with a 5 Bar gauge might not work really well. Maybe you have a gauge / sender mismatch.
My gauge shows 0 at hot idle, but my oil light does not come on.
Overfilling will not cause a reduction in oil pressure. It will cause oil to be blown out of the tank thru the vent.
On cold startup, my engine throws 100+ psig at 2K RPM, but then settles down to about 10 psig per 1000 RPM.
Electrical gauges are subject to 40 year old wiring connections. I would buy a cheap mechanical gauge and plumb it in to verify your gauge readings.
+1
Mechanical gauges are great and give you piece of mind. I had a big red light installed on my dash that would light up if low oil pressure was experienced. Motors are expensive and gauges or warning lights cheap!
Posted by: stownsen914 Apr 24 2014, 12:56 PM
Can't speak for the oil light, but on flat sixes up to the 3.0L, the gauge was a 10 Bar (140 psig). Using a 10 Bar sender with a 5 Bar gauge might not work really well. Maybe you have a gauge / sender mismatch.
The above was my first thought ...
If you've got the right parts, sometimes they do go bad, so you can try swapping them out if you (or a budd) happen to have a spare.
Also make sure your ground is good.
Oil pressure is a really important thing to have right, so do figure it out before you run the engine much.
Scott
Posted by: brant Apr 24 2014, 01:50 PM
Can't speak for the oil light, but on flat sixes up to the 3.0L, the gauge was a 10 Bar (140 psig). Using a 10 Bar sender with a 5 Bar gauge might not work really well. Maybe you have a gauge / sender mismatch.
The above was my first thought ...
If you've got the right parts, sometimes they do go bad, so you can try swapping them out if you (or a budd) happen to have a spare.
Also make sure your ground is good.
Oil pressure is a really important thing to have right, so do figure it out before you run the engine much.
Scott
I Agee you should figure this out.
What are the motor compression numbers and mileage.
Definitely worth trying the senders too
Posted by: yeahmag Apr 24 2014, 03:29 PM
I always wanted to mount a mechanical sender in the engine bay. What are you guys running for a quality unit?
Posted by: Cap'n Krusty Apr 24 2014, 04:01 PM
911s, even the 2 liter engines, run what most non-Porsche people consider scary low oil pressure. When the 2.7 came to market, Porsche changed the oil pressure switch for the light to one with a lower threshold so the light wouldn't come on at idle. At this time, that switch is what you put in all the air cooled 911 engines. If your switch is working correctly and the light comes on at 900 RPM, you're running at less than .5 BAR. That's around 7 PSI. If your temps aren't unusually high, if you're running 20w50, and your idle isn't less than 900 RPM, you may have a problem. First thing I would suggest is installing updated cam tower oil fittings. They're somewhat more restrictive and should raise your overall oil pressure a little. After that, you may have to look into major surgery ......................
The Cap'n
Posted by: 914itis Apr 24 2014, 04:40 PM
I just spoke to a local expert who confirmed the capt'n's post about the low pressure on these 2 litter motors. As far as the pressure gauge, I will try a mechanical gauge and see the results.
Compression was at 175 lbs all around .
Motor runs great.
Posted by: 914itis Apr 26 2014, 06:00 AM
Any recommendations , thread size on a mechanical pressure gauge that can be had at the local FLAPS?
Posted by: 914itis Apr 26 2014, 09:03 AM
Feeling better today, I pulled the sender and it is a 10 bar gauge. That makes me feel a lot better.
As always you guys nailed it!
now on the hunt for a 5 bar sending unit.
Posted by: Steve Apr 26 2014, 09:25 AM
Pelican sells them.
I just bought one for my Tri gauge cluster
http://www.pelicanparts.com/cgi-bin/smart/more_info.cgi?pn=911-606-111-03-M82&catalog_description=&Oil%2520Pressure%2520Sender%2520%2528requires%2520additional%2520sealing%2520ring%252C%2520part%2523%2520%2539%2530%2530%252D%2531%2532%2533%252D%2530%2530%2539%252D%2532%2530%2529%252C%2520%2539%2531%2531%2520%2526%2520Turbo%2520%2528%2531%2539%2537%2538%252D%2538%2533%2529%2520
Posted by: 914itis Apr 26 2014, 11:03 AM
Pelican sells them.
I just bought one for my Tri gauge cluster
http://www.pelicanparts.com/cgi-bin/smart/more_info.cgi?pn=911-606-111-03-M82&catalog_description=&Oil%2520Pressure%2520Sender%2520%2528requires%2520additional%2520sealing%2520ring%252C%2520part%2523%2520%2539%2530%2530%252D%2531%2532%2533%252D%2530%2530%2539%252D%2532%2530%2529%252C%2520%2539%2531%2531%2520%2526%2520Turbo%2520%2528%2531%2539%2537%2538%252D%2538%2533%2529%2520
Thanks
That's a single . I need a dual sender .
Posted by: Dave_Darling Apr 26 2014, 11:42 AM
How about this one, then?
http://www.pelicanparts.com/cgi-bin/smart/more_info.cgi?pn=VDO-360025&catalog_description=&%253Cfont%2520face%253D%2522Verdana%252C%2520Arial%2522%2520size%253D%2522%2532%2522%253EVDO%2520Oil%2520Pressure%2520Dual%2520Sender%252C%2520%2538%2530%2520PSI%2520%2528retains%2520the%2520use%2520of%2520the%2520green%2520oil%2520pressure%2520light%2520on%2520dash%2529%2520sender%2520%253Cbr%253E%2520%253C%252Ffont%253E%253Cfont%2520face%253D%2522Verdana%252C%2520Arial%2522%2520size%253D%2522%2531%2522%253E%2520%2528for%2520use%2520with%2520green%2520light%2520on%2520gauge%2529%253C%252Ffont%253E
--DD
Posted by: Steve Apr 26 2014, 08:53 PM
How about this one, then?
http://www.pelicanparts.com/cgi-bin/smart/more_info.cgi?pn=VDO-360025&catalog_description=&%253Cfont%2520face%253D%2522Verdana%252C%2520Arial%2522%2520size%253D%2522%2532%2522%253EVDO%2520Oil%2520Pressure%2520Dual%2520Sender%252C%2520%2538%2530%2520PSI%2520%2528retains%2520the%2520use%2520of%2520the%2520green%2520oil%2520pressure%2520light%2520on%2520dash%2529%2520sender%2520%253Cbr%253E%2520%253C%252Ffont%253E%253Cfont%2520face%253D%2522Verdana%252C%2520Arial%2522%2520size%253D%2522%2531%2522%253E%2520%2528for%2520use%2520with%2520green%2520light%2520on%2520gauge%2529%253C%252Ffont%253E
--DD
That would be equal to 5.5 bar. I guess that's close enough.
Posted by: 914itis Apr 28 2014, 12:15 PM
Picked up a 5 bar sender from the great Bruce . I got it today and my pressure is fine.
Thanks to you all.
Posted by: SLITS Apr 28 2014, 02:09 PM
Picked up a 5 bar sender from the great Bruce . I got it today and my pressure is fine.
Thanks to you all.
Posted by: bcheney Apr 28 2014, 06:49 PM
So glad this had a HAPPY ENDING 
Posted by: Vacca Rabite Apr 28 2014, 07:17 PM
Zach
Posted by: r_towle Apr 28 2014, 07:36 PM
So glad this had a HAPPY ENDING
Happy endings are the best type.
Posted by: 914itis Apr 28 2014, 08:25 PM
So glad this had a HAPPY ENDING
Happy endings are the best type.
when starting the conversion, I had a 10 bar gauge, then this one comes up in the classified, I like it better, I purchased it and install without ever thinking of the sender.
Ihad to find a sender quick, I couldn't digest having to embrace for the worst.
Happy ending indeed .
to all
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