vjd3

It was nighttime and 78 degrees when it happened to me and it still shot up and stayed there all the way home ...

The fan turns on by itself at programmed points ... I suspect the low speed comes on at about 225 and the high speed at 248. I just leave it on high all the time ... but if I had the switch, I think I would hit it as soon as it rose above the first mark (194 or 8 o'clock) and it will never go higher.

Vic
95 C4

Arrwin

The only reason why i'm a little nervous is b/c I don't remember it reaching the 9 o'clock position at all (maybe 1 or 2 times) last summer. Maybe it wasn't as humid??

Texas993

Hey Joon, which shop?

Are you joining us next Sunday for the drive?

My solution to oil cooling on extremely hot days is to leave the 993 in the garage. Not as much fun, but the AC in my Benz sure blows cold.

vjd3

Ha ... PJ, if I move out there, do I need to buy a Benz, too?

Vic
95 C4

fbfisher

To let your car run at 9 - 10:00 position is punishing the car and in the end, your wallet. The high speed fan is programmed to come on WAY to late and it shuts down WAY to soon. I prefer to use the fan switch to keep the car running "in the zone" at all times. The only time I let it get hotter is when I want to check the oil level.

Texas993

The p-car AC is fine up til about 105, after that it is marginal. If you leave your car parked outside during the day in the sun, it is impossible to cool.

Mine is black/black and that is a contributor to the issue. But the engine runs cool. I rarely see any temps above 9 o'clock.

The Kia Rio I rented had a sufficient AC... so you don't have to get a Benz.

joon

Patrick, Stuttgart told me this. I'm planning on going for the drive, but then again, it depends if baby (my daughter) is needy or not from the previous night. At least I may meet up with your guys for coffee of something, even if I don't do the drive. Yeah....I normally leave the 993 in the garage on hot days...but heck, sometimes I just have to take her out regardless to get my fix.

DarrylH

Here's how I look at it. If Porsche's engineers wanted the oil temps to never rise above the 200ish degree mark, why wouldn't they have set the low-speed fan to come on at that temperature? Woulda been easy. They coulda chosen any temp they wanted for the startup of the fan when they designed the system. They chose 220ish for the first stage and 250ish for the second (which I consider an emergency, worst-case scenario mode.) Under any normal circumstances, the oil heats to the low-speed fan start point, the fan kicks in, and it cycles off and on as required. I've never heard my high-speed fan except when testing it and when the ballast resistor died, and yes, I know I'm in the Great White North but it gets plenty hot here.

As long as the low-speed fan of your oil cooling system is working, keeping the temps on the gauge between about 9 and 9:30 at max, I'm still not convinced that you're significantly improving the longevity of your engine by running the fan manually. Just drive, and enjoy, and don't worry too much.

Dave R.

Isn't it true that the oil temperature gauge sensor measures temperature of oil that has returned from the oil cooler, but has not yet been fed to the engine parts that need lubrication/cooling?

If so, the actual temp of oil exiting the engine may be a lot higher than the gauge might suggest...

My morning commute in a 964 has a long highway stretch before a final stint of street lights. In the summer, on the highway the temp needle is about 2/3 into the first large zone - 5 minutes of stoplights later, the temp needle will be at or above the 9 o'clock position. That temperature rise happens a lot faster than when the car is first warming up, before the thermostat opens. I guess I'm seeing the effects of heat soak when the oil cooler is less effective.

the_buch

There is no downside to the fan over-ride ... you can still let the oil get as hot as you personally believe is appropriate ... but, I can assure you, there will be a traffic situation in which you will conclude this may be the best mod you have done :-)

BIG-BRO

I put in the over-ride switch last week (including the blinking LED in the switch as a reminder it's on), and am glad I have it as an option. Yes, in "normal" driving the overall system works OK, but when sitting still in hot weather the temp creeps up and having the option to flip the fan on brings it right down quickly. And today at the track....yes, it sure comes in handy. Gives me the ability to get the temp down after coming off the track.

Phil

Well, I'm no Porsche engineer, nor a mechanic,

Now, I 've had one 993, but I'll admit that I beat on it pretty dang hard all the time. Mine never went past 10 o'clock on the oil temp gauge, and that was (I think) only twice, at Streets of Willow (which is all second and third gear, bouncing off the rev limiter for a good portion of the lap) when the ambient temp was over 110F. My motor ran really strong.

MY thinking is that air cooled motors are made with very loose tolerances on a lot of the parts, so that when the engine gets up to operating temp (at least 9 o'clock?) the parts fit much better together. When the motor is cooler than that, the parts don't fit well, and you're not supposed to drive it hard when it's not warm enough.

luke byron

If you do the over-ride switch mod. does it eliminate the the normal low speed and high speed auto cycle? Where can I get information on how to do the over-ride switch?

Thanks.

EThec

the over ride switch has no affect on the normal operation of the system when in the off position. just turn it on to turn the fan on high.
go here for more info.
www.p-car.com

Edward

There is no downside to the over-ride switch, IMHO. It is simply there to use at your discretion. One doesn't have to actuate it if one is comfortable with the oil going to 9:00 (or greater). But even if one IS comfortable with these oil temps, the switch is useful for bringing temps down more rapidly since the high-speed fan automatically switches down to low speed even before the needle has come back down to the 9:00 position yet. It is also very useful at bringing the oil temp down rapidly on the track at the cool-down lap. I know my temp needle drops MUCH more quickly (at the cool-down lap) when compared to the times I've forgotten hit the override switch. All in all, I just don't see a downside to this mod, but to each his own.

Edward



Edward