Porsche 964 Idle and oil pressure variations
04-26-2017, 09:48 PM
#16
Hi Andrew,
My oil pressure varies between 1.5/2 when its hot. The problem is some oil pressure variations combined with idle variations. When i decelerate the tachometer goes below 500 and the oil pressure below 1. Is that a normal behaviour? I am new at this.
Thanks a lot,
JP
My oil pressure varies between 1.5/2 when its hot. The problem is some oil pressure variations combined with idle variations. When i decelerate the tachometer goes below 500 and the oil pressure below 1. Is that a normal behaviour? I am new at this.
Thanks a lot,
JP
Yes, that is completely normal -no need to worry.
04-26-2017, 09:50 PM
#17
Those numbers are high. The OP's numbers are more typical.The variation is due to the oil pressure sensor or the gauge itself - I changed several out before figuring that out.
04-27-2017, 06:18 AM
#19
Burning Brakes
Idle can possibly be solved with a system adaption using the Bosch hammer. If this fails to cure the idle I would suggest changing the oxygen sensor on the exhaust cat.
04-27-2017, 06:32 AM
#20
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Thanks a lot JJJMCD. I´m more confident.
However, next week i will go to a independent mechanic (Porsche specialist) to hear a live opinion.
Can you recommend what kind of engine oil viscosity i should use to this specific car?
Best regards,
JP (not OP)
However, next week i will go to a independent mechanic (Porsche specialist) to hear a live opinion.
Can you recommend what kind of engine oil viscosity i should use to this specific car?
Best regards,
JP (not OP)
04-27-2017, 07:02 AM
#21
Track Day
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04-27-2017, 08:48 AM
#24
Rennlist Member
I have had three different 964's that don't belong to me in my garage in the past couple of months one 90 C2 one 91 C2 and a 91C4 and their oil pressure was more like my car than what we are discussing. My turbo and track car read similar to my C2 as well.
I have been looking at a number of other 964's all different years for potential buyers and I observed more that responded like my car than the OP. I had been keeping an eye on different cars and how their pressures read since I started discussing this with others and I am getting different opinions.
I agree as I stated that these cars do vary and you have to get to know the individual car. I think what is most important is that the pressure builds and is high enough under WOT. The earlier torsion bar cars had varying gauge readings and also different gauges that were calibrated differently within the same MY. I guess this is worthy of discussion and what similarities and differences exist for a car that reacts one way vs another.
My C2 runs flawlessly and is all original engine and sending unit with 61k miles and has always ran this way since I purchased it back in 2005. My turbo the same with far less miles and again reacts the same as my C2? I am wondering if mileage can have something to do with this as well.
I use Mobil 1 15W50 in all my cars but I only drive them in temperatures above 45 degrees usually warmer and I always drive them hard.
Edit: there are a number of threads on this with different opinions.
Some are saying typical for higher mileage cars
Others saying sounds like the begining of oiling problems
Others saying signs of leaks and seals needing replacement
Not sure what is the truth but as I said I think a fresh oil change would be the best place to start.
Last edited by cobalt; 04-27-2017 at 09:08 AM.
04-27-2017, 08:48 AM
#25
10w40 grade semi or fully synth is typical but you may want to adjust slightly for warmer climate. Search engine oil posts on this forum and you will find many many recommendations.
Oh, and it's worth noting that the oil reading any car sees will vary by grade of oil at any given temperature too, which might explain differences in opinion.
Oh, and it's worth noting that the oil reading any car sees will vary by grade of oil at any given temperature too, which might explain differences in opinion.
04-27-2017, 09:32 AM
#26
Really?
I have had three different 964's that don't belong to me in my garage in the past couple of months one 90 C2 one 91 C2 and a 91C4 and their oil pressure was more like my car than what we are discussing. My turbo and track car read similar to my C2 as well.
I have been looking at a number of other 964's all different years for potential buyers and I observed more that responded like my car than the OP. I had been keeping an eye on different cars and how their pressures read since I started discussing this with others and I am getting different opinions.
I agree as I stated that these cars do vary and you have to get to know the individual car. I think what is most important is that the pressure builds and is high enough under WOT. The earlier torsion bar cars had varying gauge readings and also different gauges that were calibrated differently within the same MY. I guess this is worthy of discussion and what similarities and differences exist for a car that reacts one way vs another.
My C2 runs flawlessly and is all original engine and sending unit with 61k miles and has always ran this way since I purchased it back in 2005. My turbo the same with far less miles and again reacts the same as my C2? I am wondering if mileage can have something to do with this as well.
I use Mobil 1 15W50 in all my cars but I only drive them in temperatures above 45 degrees usually warmer and I always drive them hard.https://m.facebook.com/asya.dzhabbarova
Edit: there are a number of threads on this with different opinions.
Some are saying typical for higher mileage cars
Others saying sounds like the begining of oiling problems
Others saying signs of leaks and seals needing replacement
Not sure what is the truth but as I said I think a fresh oil change would be the best place to start.
I have had three different 964's that don't belong to me in my garage in the past couple of months one 90 C2 one 91 C2 and a 91C4 and their oil pressure was more like my car than what we are discussing. My turbo and track car read similar to my C2 as well.
I have been looking at a number of other 964's all different years for potential buyers and I observed more that responded like my car than the OP. I had been keeping an eye on different cars and how their pressures read since I started discussing this with others and I am getting different opinions.
I agree as I stated that these cars do vary and you have to get to know the individual car. I think what is most important is that the pressure builds and is high enough under WOT. The earlier torsion bar cars had varying gauge readings and also different gauges that were calibrated differently within the same MY. I guess this is worthy of discussion and what similarities and differences exist for a car that reacts one way vs another.
My C2 runs flawlessly and is all original engine and sending unit with 61k miles and has always ran this way since I purchased it back in 2005. My turbo the same with far less miles and again reacts the same as my C2? I am wondering if mileage can have something to do with this as well.
I use Mobil 1 15W50 in all my cars but I only drive them in temperatures above 45 degrees usually warmer and I always drive them hard.https://m.facebook.com/asya.dzhabbarova
Edit: there are a number of threads on this with different opinions.
Some are saying typical for higher mileage cars
Others saying sounds like the begining of oiling problems
Others saying signs of leaks and seals needing replacement
Not sure what is the truth but as I said I think a fresh oil change would be the best place to start.
Yes, according to the Porsche 964 owners manual, normal is 1 bar at idle (800 rpm) when hot (9:00pm on the oil temp gauge) and an additional 1 bar per 1,000rpm. If idle is a little low (500-600rpm), oil pressure at idle will be correspondingly lower. I had my car tested with an external oil pressure gauge and swapped out three oil pressure sensors and we determined that the variation in indicated oil pressure was due to some sensors and oil pressure gauges
Last edited by JJJMCD; 04-27-2017 at 11:49 AM.
04-27-2017, 09:40 AM
#27
Hi Anthony,
Thanks a lot again for your attention.
What i was trying to say is that the fan is always working, not the AC. But next week i will check it with a independent mechanic (Porsche specialist) and see if anything is wrong.
I have a passion for classic motorbikes and its much more easy to understand what is right and wrong.
Can you recommend a engine oil to this car (15w40?? 20w50??)?
Best regards,
JP
Thanks a lot again for your attention.
What i was trying to say is that the fan is always working, not the AC. But next week i will check it with a independent mechanic (Porsche specialist) and see if anything is wrong.
I have a passion for classic motorbikes and its much more easy to understand what is right and wrong.
Can you recommend a engine oil to this car (15w40?? 20w50??)?
Best regards,
JP
10w40 non-synthetic. Synthetic oils are thinner and will yield lower oil pressure.
04-27-2017, 09:45 AM
#28
Rennlist Member
Yes, according to the Porsche 964 owners manual, normal is 1 bar at idle (800 rpm) when hot (9:00pm on the oil temp gauge) and an additional 1 bar per 1,000rpm. If idle is a little low (500-600rpm), oil pressure at idle will be correspondingly lower. I had my car tested with an external oil pressure gauge and swapped out three oil pressure sensors and we determined that the variation in indicated oil pressure was due to some sensors and oil pressure gauges
This is contradictory to most 964's I have seen. Mine reads as follows but I am used to seeing pressures more in line with my car than as you noted.
04-27-2017, 12:37 PM
#29
Technical Guru
Rennlist Member
Rennlist Member
One thing I learned when comparing minute oil pressure & level differences between older 964s is to make sure you clean the pin contacts on the back of the gauge first (use a pencil eraser, contact cleaner does not remove tarnish or corrosion...) The tarnish that builds up on the pin contacts changes the resistance in a non-linear fashion.
The same process should be followed before bending the float level on an oil level sensor to match the gauge too, but...
The same process should be followed before bending the float level on an oil level sensor to match the gauge too, but...
04-27-2017, 12:51 PM
#30
Rennlist Member
One thing I learned when comparing minute oil pressure & level differences between older 964s is to make sure you clean the pin contacts on the back of the gauge first (use a pencil eraser, contact cleaner does not remove tarnish or corrosion...) The tarnish that builds up on the pin contacts changes the resistance in a non-linear fashion.
The same process should be followed before bending the float level on an oil level sensor to match the gauge too, but...
The same process should be followed before bending the float level on an oil level sensor to match the gauge too, but...
