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Old 12-07-2010, 11:52 PM
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Low oil temps

Recently with the cold weather (20s to 40s F) I have noticed that my oil temperatures are very low. I am measuring the temps with a SPA oil temp and pressure gauge with the sensor mounted to a Racing Beat oil filter adapter.

Car is normally warmed up until water temp hits 130F which takes a few minutes. At this point oil temp is normally 65Fish and will reach 100F within five to ten minutes. After 100F the temps will climb 1 degree every 2-3 seconds at idle or in stop and go traffic. Temps will hold firm from 10 to 25mph. As soon as I start moving at a between 40-60mph the temperature will drop down very quickly and settle somewhere between 100-115F. Once stopped or moving slow again temperatures will climb again but at the same linear rate (so it's not like it was just reading low while moving and not showing the real temp somehow). The max temp I've ever seen was 165F twice but once was idling for probably 20+ minutes and the other was a half an hour of stop and go traffic.

I generally stay out of boost since I'm cautious about the temps but on the occasions where temps have climbed up above 150F in stop and go and there was a break I would do a few back to back WOT to about 7000-7500RPM but it will not affect the oil temps at all really. Even during those few hard pulls the temps will plummet sometimes back down to 110F within seconds. They also don't climb significantly higher after stopping after high loads. I have been running 9.5psi on a GT3071R but it will spike a bit higher sometimes.

For cooling mods I have a BHR radiator, Mazmart thermostat + waterpump, Evans NPG-R coolant, and early fan on from MM tune. It is using Castrol GTX 10w30 (I requested 10w40 when they clocked my turbo but that was all they had...)

I blocked off both oil coolers with a cut up black plastic folder with black duck tape layered on top of it blocking off all air routes in. Half of the passenger-side vents in-front of the tire are also blocked off.

The coolant temps are from 175F to 190F depending on the situation.

Should I continue to keep blocking off the rear oil cooler vents? Is there something about using the oil filter adapter I am not thinking about where the temps would be significantly lower? I tried to find some switch where I could simply re-route the oil to not run through the coolers but couldn't find any (a switch for each in the interior).
Old 12-08-2010, 07:18 AM
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Oil cooler thermostat seems not to be working.
Old 12-08-2010, 09:30 AM
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I'm measuring oil temps at the filter with the RB adapter and I also have Cobb with MMCCS.
Break out the calculator cuz I work in metric.
In 8 Celsius weather my oil temps run at 72 - 74 C @ 120kph
(46F, 160 - 165F, 74MPH)
Oil temp rises slowly compared to water temp in cold weather.
Hard driving in cool weather will get the oil temp up to 85 C (185F) but it will return to 74C on the highway in cruise.
Warm up time to reach 74 C in steady highway driving is 15 - 20 min.
I did not have any blockage on the oil coolers.

Remember that the oil temp being measured at the oil filter is after the oil coolers before re-entering the engine.

Hope this helps

Last edited by DarkBrew; 12-08-2010 at 09:34 AM.
Old 12-08-2010, 11:16 AM
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Originally Posted by fevest
Oil cooler thermostat seems not to be working.
The factory thermostat is not a true thermostat, it always allows oil to flow.

OP,

Okay, first remember that where you are measuring is on the return after the coolers so the temp will be lower than what it actually is going into the coolers. But still those temps are way low and it is weird because typically my oil temps are fairly close to what the coolant temps are.

Can I ask what oil pressure readings you are seeing?
Old 12-08-2010, 11:29 AM
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I think cold oil temps in cold weather are a common problem (see: milky oil). The adapter plate location is not ideal when trying to compare it to coolant temperature (either measured from the OBDII or on the heater hose), because the *inlet* oil temp, not the *internal* oil temp. My water temp on the exit of the radiator usually reads ~165 F when the OBDII temp is reading 180 deg F. Some have gotten warmer oil temps for winter use by blocking both sides of the oil coolers with pieces of foam.
Old 12-08-2010, 11:35 AM
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block both sides of both coolers. You dont want oil to heat or cool too rapidly.
No switch, nothing else unless you want to replace the enite oil cooling system. Thats too cool.
Also check your sensor. It could be bad. If your coolant temps are 180-190 and your oil temps or at 115F---somethings wrong.
OD
Old 12-08-2010, 11:37 AM
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Originally Posted by 9krpmrx8
Can I ask what oil pressure readings you are seeing?
I see about 16psi at idle but dip down to as low as 13psi on occasion, on cold start it holds pretty firm though. When driving normally I believe I'm in the 55-60psi range.

Edit: I have the Mazmart oil pressure mod but it is not installed yet. It was supposed to be installed with the turbo I guess it slipped through the cracks.
Edit#2: I also have a GReddy oil pan if that makes a difference

Last edited by IronTanuki; 12-08-2010 at 11:45 AM.
Old 12-08-2010, 11:41 AM
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Originally Posted by olddragger
block both sides of both coolers. You dont want oil to heat or cool too rapidly.
No switch, nothing else unless you want to replace the enite oil cooling system. Thats too cool.
Also check your sensor. It could be bad. If your coolant temps are 180-190 and your oil temps or at 115F---somethings wrong.
OD

^ Yep. My oil and coolant are almost always pretty close despite load and ambient temps.
Old 12-08-2010, 11:50 AM
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For the situation above my coolant will hit 85C and my oil will run 72 - 74C on the highway.
Your pressure sounds normal.

I have the oil pressure mod installed... I've seen 8Kg/cm2 indicated although I had to hold high RPM for while to let the gauge respond.... LOL

Last edited by DarkBrew; 12-08-2010 at 11:53 AM.
Old 12-08-2010, 11:21 PM
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Took this tonight, don't pay attention to ambient temp in stock cluster, it was about 46 out when I took the pic. Reading on the radio is oil temp. This was after a spirited drive home from dinner

http://www.flickr.com/photos/9krpmrx8/5245938912/http://www.flickr.com/photos/9krpmrx8/5245938912/ by http://www.flickr.com/people/9krpmrx8/, on Flickr

Last edited by 9krpmrx8; 12-09-2010 at 09:58 AM.
Old 12-09-2010, 09:51 AM
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Originally Posted by 9krpmrx8
Took this tonight, don't pay attention to ambient temp in stock cluster, it was about 46 out when I took the pic. Reading on the radio is oil temp. This was after a spirited drive home from work

Umm, way different than what I would see, but then, unlike 9krpm, I still have a lot of stock parts under the hood.
Old 12-09-2010, 09:58 AM
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Originally Posted by HiFlite999
Umm, way different than what I would see, but then, unlike 9krpm, I still have a lot of stock parts under the hood.
I'm curious, What numbers would you see?
Old 12-09-2010, 09:59 AM
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I monitored my pressures more closely yesterday and it is at 68ish psi on cold start up and tapers off slowly as the oil temp rises. Idle is between 13 and 18 psi, it will normally hold within 2-3 psi. Off idle to about 2500rpm are in the 30s and low 40s. 2500 to 3500rpm is mostly high 40s to 50s and above 4000 rpm is in the 60s with it holding a max of about 68psi.

From 158F the temps dropped to 110 within 2 minutes traveling at 40-60mph even with accelerating hard several times in a row and holding the rpms at 5-6k when not accelerating.

I will try covering up all the rear vents sometime this week and see what effect if any that has.
Old 12-09-2010, 10:07 AM
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Weird. The best thing to do would be to take oil pressure reading as described in the FSM from the fitting the factory oil pressure sending unit goes. It is pretty easy to get too. Low oil pressure can be no bueno.
Old 12-09-2010, 10:22 AM
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Originally Posted by IronTanuki
I monitored my pressures more closely yesterday and it is at 68ish psi on cold start up and tapers off slowly as the oil temp rises. Idle is between 13 and 18 psi, it will normally hold within 2-3 psi. Off idle to about 2500rpm are in the 30s and low 40s. 2500 to 3500rpm is mostly high 40s to 50s and above 4000 rpm is in the 60s with it holding a max of about 68psi.

From 158F the temps dropped to 110 within 2 minutes traveling at 40-60mph even with accelerating hard several times in a row and holding the rpms at 5-6k when not accelerating.

I will try covering up all the rear vents sometime this week and see what effect if any that has.
Assuming you have a stock oil system, that 68 psi reading is when the oil bypass opens and starts to limit oil flow (at that rpm). With the mazmart mod, which bumps the bypass pressure to 120 psi or so and 10W-30 Castrol GTX, a ~50 F cold start gives me 95-100 psi for the first few seconds, tapering down from there over the next minute or so. It's another seeming advantage of this mod - giving more flow during the first ~minute after a cold start. Above ~4,500 rpm the flow does not further increase with rpm, but does with the modded system.

The 68 psi max that you're reading kinda hints that you gauge calibration isn't all the good - it should be in the 70's. Do you have only the single wire from the sensor running back to the gauge head? If so, you're using the "body" ground which can mess up the readings in strange ways. Try clamping an independent wire to the sensor and run that ground back the the gauge head and tie it to the same ground wire used for the gauge itself.

Last edited by HiFlite999; 12-09-2010 at 10:29 AM.
Old 12-09-2010, 10:51 AM
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Originally Posted by 9krpmrx8
I'm curious, What numbers would you see?
From memory (dangerous):

In 75 mph cruise with outside air say 65 - 85 deg F, I see the adapter plate oil temps running around 165 deg F. Probably not coincidentally, I see that the water temp, measured from the radiator to the engine, is nearly identical with the OBDII water temp at 180 F. Turning on the AC, causes the inlet water temp to rise about 10 deg F in a couple of minutes to about 175 F, followed by the oil temp rising about 5 deg F. One is "loading" the radiator by heating the air reaching it, causing that bit of extra heat to be extracted from the oil system. Above 90 F or so with the AC on, one sees the the inlet water gets too hot to keep the OBDII water at 180 F and that's when it starts drifting up.

Driving hard is so subjective it's difficult to make a comparison. When I do that, it's for short periods and the OT doesn't have time to fully react. I can get the OBDII water temp up to around 200 F, but that's rare. I think the only time I've seen 200 F on the OT is in 95 deg weather with the AC on in bumper to bumper.

To really sort this out it would be a big help to either measure the OT from the stock OP sender location on the center iron, or even better, measure the temps at both the entrance of the engine (adapter plate), and at the exit.
Old 12-11-2010, 10:24 PM
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Oil "cooler" hence being "cold"
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