Denimir

iTrader: (1)

Hello eveyone,

Since I have mounted a bigger radiator on my car, I've noticed a big decrease in my oil temps and my main concern is comming when the outside temp is 10 celsius or bellow. At about 10 degrees, I am having oil temps at 55-60 max, however today the temepratures dropped around 0 and I was not able to make my gauge detect any oil temp (the minimum is 50 celsius), which means that they were bellow 50 or be bellow all the time. I am having a Lamco gauges (another question for those gauges, I have never seen combination like this, boost presure, oil temp, oil pressure before, is this custom made or?), I left the car running for 10 minutes at one place and the oil temperature went as usual 70 degrees, however once I started driving it went back to 50 or bellow.
I need your opinion on this, is this normal, should I drive the car at winter and is it save to go above 4000 rpm with such low oil temps? Additionaly, I am planning to go skiing next month in the mountain where I expect the temperature to be way bellow 0.
I am running Motul V300 Competition 15W50.

P.S. this picture is from a few months ago.

I appreciate your support!

m40ttc

Maybe a silly question but are you sure it’s reading oil temperature and not coolant temperature?

Denimir

iTrader: (1)

No worries, but I am for sure reading the oil temps, the sensor is locateted on the bottom of my oil pan in place of the drain plug, which actualy after thinking, this might be the reason. Due to the snow today or just the cold air bellow the car, it affects the readings on the sensor, so I might have to change it's position. Does that make any sense to you guys?

DDS789

iTrader: (2)

Pretty sure oil temp sensor isn't supposed to be located in the sump

From memory there's an engine block bung on the top side of the engine that will give much more accurate temp readings.

As you mentioned the sensors location plus recent weather will be what's causing issues

NOSSY_89

As soon as you said it was near the drain plug I thought yep thats the issue there. They are notorious for failing there in that set up but thats not to say sensors in other locations don't fail too but just don't seem to be as common. Like @DDS789 said take it from the other location.

Sad Weevil

iTrader: (1)

I had the same Lamco gauges on my GF8, but with the boost on the right hand side. My sensor was in the drain plug too, once warmed up it seldom went below 70 no matter what the weather. Do you have an accurate reading of the coolant temp? Since this started after fitting the bigger rad, maybe you're running too cool?
I used Millers 10W40. I never used more than 3000rpm until the temp was 70 degrees at least. Hope this helps.

Linksfahrer

I use Motul 300V 15W-60 racing oil and continue to do so even if the outside temperature is 10 Degrees *


Although excellent for 40 degree German summers ,
the lower Visco versions are also excellent.
the 10W50 is probably the better UK allrounder .

However I would certainly not just drive off if the outside temperature was 0 Degrees / cannot yet see my oil temperature on gauge scale.

Here is why :



* I would not have any concern about driving my car away with my oil temperature gauge showing of 50 Deg C
The difference is I need to wait for 20 degrees longer warm up before driving off.

Although my grade has a higher viscosity than yours and at all temperatures than any of these above
you can clearly see from the chart that by 50 degrees C they all come down fast to a lower working viscosity level.

If I may venture to do so , either you have to wait until your Gauge shows 50 Deg C or you need to change your oil to say a 5W30 or 10W30
and even then Id still give the engine a minimum 90secs or so before gingerly moving off just to get it all over the camshafts and splashed to the bores.

At 5-10 degrees ambient I just leave mine 5 mins running before I get in ,
my oil gauge starts moving off the stop at about 45 Deg and I move when it reaches 50 Deg It takes a fair bit longer if there is ice on the windows.

Using a synthetic 10W30 especially in lower ambient temperatures will help enormously as these have esters which work well to prevent skipping/scuff at all temperatures.

I would still be quite happy to continue to use your new radiator as what it will do is give your oil a longer life especially when used at higher temperatures ,
( Either higher ambient temperatures or in Engines at higher levels of tune and or Std in hard use ) you just need to bear in mind that by using it you create a little longer warm up phase
and in theory can create over cooling when driving in extreme low temperature situations (especially at higher speeds).

If you check some of my 2018 posts you will see I managed to ruin my first rebuilt Sti Pistoned engine by not warming it up sufficiently. although the lesson learned was also to use race clearances on the piston rings.
I ran foot floored in Germany in -10 deg after maybe only 10 mins of normal driving. The cooling achieved at 120mph + resulted in scuffed walls /pistons that led to a big end failure. So I have learnt my lesson.

As oils viscosity index is destroyed at a much higher rate at lower and higher temperatures even 20W50 oil ends up acting more like 15W40 when its been subjected to 110-120 Deg C when its viscosity index are significantly damaged thru higher mechanical shearing.
And that continues to occur at lower "normal" operating temperatures just a lower rate over time. While shear happens much faster at higher temperatures it also occurs if the mechanical components are not effectively
covered by a thin film of oil at the lower temperatures. It follows that if you rev your engine cold , then the film of oil critical to coating components might be ripped /torn as the film is unable to reach into tight clearances
and then metal to metal contact occurs. either way the oils propensity to lubricate is also irrecoverably degraded at this shear point. So this is another reason that you have to consider frequent oil changes depending on your user profile.

Hope this experience helps you not to worry, and yet get lots of good mileage fun.

Linksfahrer

Forgot to say I would not worry too much about having the oil temp sensor pick up being in the sump until the summer,
as for the moment you are primarily interested in the lowest temperature point of the oil.

And if you are worried about over cooling you could of course just put some tin foil over a percentage of the radiator but don't forget to take it off after your ski holiday

sti.dean

Are you running a low temperature thermostat as well ? I had to put a standard one back on my car due to not being able to get oil up to temp in the colder months when driving normally

Linksfahrer

If he has a uprated thermostat and it has failed (in open position) then this would indeed explain the overcooling.