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Join Date: Sep 2006
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911 Oil Pressure Guage Replacement Required?
I have an 88 911. I wish to replace the oil temp guage which has only markings with one that has numbers. I was planning to order the package Pelican has. Today I noticed that my oil pressure guage fluctuates a lot, moving quickly from about 1 to 3 whenever the car is idling, such that it is useless for indicating the oil pressure. In fact, the only time it really seems to give a steady reading once it is warm is when it is revving hard, and then I read the oil pressure up at 5. I know that there is no problem with my oil pressure. I have only had the car for a few months. Is it normal for the guage on a 911 to fluctuate a lot? If not, is there a way to tell if the problem is the guage or a sending unit? If I am going to replace the oil temp guage, then it may just make more sense to put in a whole new guage.
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06-30-2007, 01:31 PM
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Location: Galivants Ferry, SC
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I've posted this before to help people avoid spending $ when it's not necessary.
Clockwise, ( for your car) as you start a the lower left corner of the temp gauge, here are the temps: top of bottom white block....60 degC ( 140 degF) 8 o'clock white slash..........90 degC (194 degF) 10 o'clock white slash.......120 degC (248 degF) bottom of red block..........150 degC (302 degF) If you allow for a bit of round-off, the Fahrenheit numbers become : 150 / 200 / 250 / 300 ...... Simple...save your money !! Pressure is RPM dependent. A healthy engine is 1 - 1.5 bar / 1000 rpm. Level fluctuates with RPM, will normally be "in red" while driving. Quite the contrary of being "inaccurate"...it precisely tells you the comings-and-goings within the oil tank. Should be mid level if not overfilled, oil at temp, idle rpm. - Wil
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Wil Ferch 85 Carrera ( gone, but not forgotten ) |
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06-30-2007, 01:48 PM
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Senior??? Oh very well
Join Date: Mar 2006
Location: Wonderful Huntington Beach, again!
Posts: 356
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My '88 (95k) oil pressure gauge used to bounce around like that...then when my mech pulled the engine he did a number of things including cleaning the oil cooler(s) and various other items....since then it does not fluctuate except at hot idle and just a tiny bit there....in the range that Wil suggests above....
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06-30-2007, 05:12 PM
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Thank you both for responding. It looks like I will be saving myself some money with Wil's numbers for the temp gauge. As for the fluctuating pressure gauge, I will see if I can get at my oil cooler to clean it a bit. Are there any other parts in particular I should look at to see if I can get the fluctuating to stop? It is fluctuating in a greater range than 1-1-5 bar at 1000rpm, which do to the rapidity of the fluctuation makes me think it cannot be a oil pressure problem, but rather a gauge problem.
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06-30-2007, 10:50 PM
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Location: CT
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A fluctuating pressure reading is often caused by a loose connection at the sending unit. Check the connection. It may be an easy fix.
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Tom Butler 1973 RSR Clone 1970 911E 914-6 GT Recreation in Process |
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06-30-2007, 10:55 PM
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Senior??? Oh very well
Join Date: Mar 2006
Location: Wonderful Huntington Beach, again!
Posts: 356
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My mech is back from vacation tomorrow. I'll talk with him and see
what he recommends....then write you in the next dayr or so....Im with you, that bouncing needle is a PITA... 
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07-01-2007, 04:05 AM
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Check connections and grounds too !!...
- Wil
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Wil Ferch 85 Carrera ( gone, but not forgotten ) |
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07-01-2007, 04:40 AM
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Thank you again for the responses. Fly4val, thanks especially for seeing what your mech will recommend.
My next question is at what temperature should I be aiming to have the car operate at the track? This 911 is exclusively a track car, used in PCA DE events and, soon, vintage racing and PCA club racing. Unlike many track 911s, the car does not have a Ruf type front mounted oil cooler, but was tracked for years in Florida apparently without any overheating issues. What readings on the track would be acceptable for operating in 30 degree celsius conditions, which are temperatures we often see here in southern Ontario in the summer. If the temperatures I am getting (which thanks to Wil I will now be able to know) are too high, then I would consider going to the Ruf type front end. If the temperatures are ok, I would be content to stay with what I have. Mark |
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07-01-2007, 07:52 AM
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It depends...you might see 248 F ( 10 0'clock) on occasion, but it should not be there for long. It might start to get there after a hard 20 minute DE run at 30 degC ambient conditions.
You'll know only after your own particular runs.... - Wil
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Wil Ferch 85 Carrera ( gone, but not forgotten ) |
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07-01-2007, 09:00 AM
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