Normal operating levels
#1
Instructor
Thread Starter
Normal operating levels
I am somewhat newer to the 996 scene, being that I only have a couple thousand miles under the belt.
What are the common operating levels for oil pressure, temp, coolant temp, etc.
Maybe it is just do to the extreme Vegas heat, but the last couple days, the car doesn't seem to be running as it should. Last 2 days, especially on the way home (5pm and 110-113º outside), the coolant temp seemed to be rising. The oil pressure seems a bit low. Battery voltage looks ok, but the meter I have on my phone plugged in is showing 12.5V, which would be low. Idle is sitting at 750 RPM.
Here is a where everything is sitting as I got to work this morning. Again, coolant temps look high, oil pressure looks low.
2000 911 C2 Cab w/ manual transmission. As you can see, just shy of 97k miles.
Things I know have been done recently:
What to look for with the cooling system? Level looks fine. I plan on flushing this over the weekend as I don't know when it was done last.
Oil pressure - I see the sending units are a common failure, along with the pressure relief valve. Could something with the low voltage and higher temps be causing this too?
Ideas to look into tonight, this weekend, etc...
Thanks![
What are the common operating levels for oil pressure, temp, coolant temp, etc.
Maybe it is just do to the extreme Vegas heat, but the last couple days, the car doesn't seem to be running as it should. Last 2 days, especially on the way home (5pm and 110-113º outside), the coolant temp seemed to be rising. The oil pressure seems a bit low. Battery voltage looks ok, but the meter I have on my phone plugged in is showing 12.5V, which would be low. Idle is sitting at 750 RPM.
Here is a where everything is sitting as I got to work this morning. Again, coolant temps look high, oil pressure looks low.
2000 911 C2 Cab w/ manual transmission. As you can see, just shy of 97k miles.
Things I know have been done recently:
- New battery - 3 weeks ago
- Oil/Filter Change - Mobile1 0W-40 Syntheic - last night - this was rather dirty, but I didn't see any metal or foreign pieces in the filter
- Transmission oil drained and filled - last night
What to look for with the cooling system? Level looks fine. I plan on flushing this over the weekend as I don't know when it was done last.
Oil pressure - I see the sending units are a common failure, along with the pressure relief valve. Could something with the low voltage and higher temps be causing this too?
Ideas to look into tonight, this weekend, etc...
Thanks![
#2
Since the coolant temp is high, both of your coolant fans could be running on the "High" setting. That could explain the lower voltage. What is the voltage reading at cold start? It should be close to 14v.
In any case, you should first verify if BOTH of your coolant fans are working in both "low" and "high" settings with no obstructions to the air flow. You can feel the air flow if you place you hand on the ground just a few inches in front of the front tires.
At cold start, turn on the a/c and both fans should be on the "low" setting. When the coolant temp is very high, both fans should be ON high.
With 0w-40 and high coolant temp, 0.8bar oil pressure may not be out-of-line.
In any case, you should first verify if BOTH of your coolant fans are working in both "low" and "high" settings with no obstructions to the air flow. You can feel the air flow if you place you hand on the ground just a few inches in front of the front tires.
At cold start, turn on the a/c and both fans should be on the "low" setting. When the coolant temp is very high, both fans should be ON high.
With 0w-40 and high coolant temp, 0.8bar oil pressure may not be out-of-line.
#3
The oil pressure seems fine for warmed up and idling. The temp is not out of line considering the ambient temperature. The voltage seems low - you should have your alternator tested.
Edit: Or just listen to Ahsai
Edit: Or just listen to Ahsai
#4
Rennlist Member
Since the coolant temp is high, both of your coolant fans could be running on the "High" setting. That could explain the lower voltage. What is the voltage reading at cold start? It should be close to 14v.
In any case, you should first verify if BOTH of your coolant fans are working in both "low" and "high" settings with no obstructions to the air flow. You can feel the air flow if you place you hand on the ground just a few inches in front of the front tires.
At cold start, turn on the a/c and both fans should be on the "low" setting. When the coolant temp is very high, both fans should be ON high.
With 0w-40 and high coolant temp, 0.8bar oil pressure may not be out-of-line.
In any case, you should first verify if BOTH of your coolant fans are working in both "low" and "high" settings with no obstructions to the air flow. You can feel the air flow if you place you hand on the ground just a few inches in front of the front tires.
At cold start, turn on the a/c and both fans should be on the "low" setting. When the coolant temp is very high, both fans should be ON high.
With 0w-40 and high coolant temp, 0.8bar oil pressure may not be out-of-line.
#5
Instructor
Thread Starter
Since the coolant temp is high, both of your coolant fans could be running on the "High" setting. That could explain the lower voltage. What is the voltage reading at cold start? It should be close to 14v.
In any case, you should first verify if BOTH of your coolant fans are working in both "low" and "high" settings with no obstructions to the air flow. You can feel the air flow if you place you hand on the ground just a few inches in front of the front tires.
At cold start, turn on the a/c and both fans should be on the "low" setting. When the coolant temp is very high, both fans should be ON high.
With 0w-40 and high coolant temp, 0.8bar oil pressure may not be out-of-line.
In any case, you should first verify if BOTH of your coolant fans are working in both "low" and "high" settings with no obstructions to the air flow. You can feel the air flow if you place you hand on the ground just a few inches in front of the front tires.
At cold start, turn on the a/c and both fans should be on the "low" setting. When the coolant temp is very high, both fans should be ON high.
With 0w-40 and high coolant temp, 0.8bar oil pressure may not be out-of-line.
Was considering going to a different viscosity oil, but already had bought the 0W-40. With this heat, I run 20W-50 in my motorcycles. Would that be an acceptable choice for the 911, at least until it drops below 100° regularly?
No strange noises. Feels and sounds great. But wasn't sure about the temps and such or if that should be expected with these cars and the Vegas heat waves.
#6
Burning Brakes
Nothing there bothers me... the temp is still touching the 0 in the 180 - so that's okay... the oil pressure is fine given the heat. The voltage - I just had my alternator fail - it becomes apparent quick. As you're driving (and running air, fans, stereo) the voltage needle continued to drop. Short version - if you haven't actually put the car on charge over the last 3 days and it's still starting fine - your alternator is likely fine as well.
I've run Mobil 15W 50 in my track car in the summer....
I've run Mobil 15W 50 in my track car in the summer....
#7
Instructor
Thread Starter
Nothing there bothers me... the temp is still touching the 0 in the 180 - so that's okay... the oil pressure is fine given the heat. The voltage - I just had my alternator fail - it becomes apparent quick. As you're driving (and running air, fans, stereo) the voltage needle continued to drop. Short version - if you haven't actually put the car on charge over the last 3 days and it's still starting fine - your alternator is likely fine as well.
I've run Mobil 15W 50 in my track car in the summer....
I've run Mobil 15W 50 in my track car in the summer....
No charger, but daily driven. No notice of hard starts.
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#9
Burning Brakes
The previous owner of my car sold it to me at a discount because he had gone through two alternators and a battery and it made him very frustrated. His Indy didn't figure it out. Within minutes after trailering the car home, I found the connection from the negative battery terminal to the body to be significantly corroded. I cleaned it up, installed a new alternator, and my car runs great. No further alternator related issues in the past year and a half.
#10
The shown voltage looks perfectly fine to me. Orherwise measure the voltage directly on the aternator. I had the alternator refurbished lately and after cold start and driving when the battery is recharged the voltage drops from around 14V a bit to 13.5V. With fans on high, mine drops sometimes to 12.9-13.0. Nothing to worry about I suppose. Would not be bad to check the ground. Higher temperatures in the engine bay mean als higher resistances which result in higher voltage drops.
#11
Rennlist Member
Your temps and oil pressure behave as they should for a car with 100k miles. As water temp increases, the oil pressure drops. I don’t believe 15w or 20w cold is a ‘certified winter’ weight for these cars, but 5w-50 is. You will probably gain oil pressure switching to 50, I know I did.
Was this is around town driving with stop and go? Or was it highway. If highway, I would check into cleaning the front radiators. If around town, this might be normal.
Here’s my advice for temps: borrow a Durametric from someone or buy an ODBII device and use a smartphone app to pulls temps from the ECU. I’ve found that the white line way past zero is where my fans will kick on, not before (unless the AC is on), and that’s because the ECU is recording temps 10F lower than my gauge on the dash (or the HVAC hack display).
Was this is around town driving with stop and go? Or was it highway. If highway, I would check into cleaning the front radiators. If around town, this might be normal.
Here’s my advice for temps: borrow a Durametric from someone or buy an ODBII device and use a smartphone app to pulls temps from the ECU. I’ve found that the white line way past zero is where my fans will kick on, not before (unless the AC is on), and that’s because the ECU is recording temps 10F lower than my gauge on the dash (or the HVAC hack display).
#12
Regarding the voltages, don't forget the alternator-starter Y-cable. They tend to go bad and have been redesigned several times. I had low voltage and replaced my voltage regulator first, but had voltage drop to as low as 12.4 at some points. Changed the Y-cable and immediately got back up to 14v without fans, 13.5 with.
#13
Drifting
OP: In your dash pic did you have the AC on? Reason I ask is my car pops the idle up to @850 with AC on. Yours appears to be a bit under 800. Not sure if that would be significant or not. Ahsai is the man...btw!
#15
Instructor
Thread Starter
Your temps and oil pressure behave as they should for a car with 100k miles. As water temp increases, the oil pressure drops. I don’t believe 15w or 20w cold is a ‘certified winter’ weight for these cars, but 5w-50 is. You will probably gain oil pressure switching to 50, I know I did.
Was this is around town driving with stop and go? Or was it highway. If highway, I would check into cleaning the front radiators. If around town, this might be normal.
Here’s my advice for temps: borrow a Durametric from someone or buy an ODBII device and use a smartphone app to pulls temps from the ECU. I’ve found that the white line way past zero is where my fans will kick on, not before (unless the AC is on), and that’s because the ECU is recording temps 10F lower than my gauge on the dash (or the HVAC hack display).
Was this is around town driving with stop and go? Or was it highway. If highway, I would check into cleaning the front radiators. If around town, this might be normal.
Here’s my advice for temps: borrow a Durametric from someone or buy an ODBII device and use a smartphone app to pulls temps from the ECU. I’ve found that the white line way past zero is where my fans will kick on, not before (unless the AC is on), and that’s because the ECU is recording temps 10F lower than my gauge on the dash (or the HVAC hack display).