(2010 C4S cab 22k miles, 6MT, Fister exhaust w/ Sharkwerks center bypass.)

So this is the highest temp I've seen on this car in my 2 years of ownership (actually got a smidge higher closer to 225). First time it's gotten this high.

Some spirited driving and occasional traffic, ambient outside temp in the low 90s.... I feel like this is too high. Not liking it. Any major concern though?

Time for a low temp t-stat?

 

That's as high as mine goes for brief periods and I have a third rad. No problem with your temps.

 

I don't think you have a problem with your oil temp. A low temperature thermostat will help it cool down faster to the setpoint and the low temp tstat is recommended by a couple of the best-known Porsche engine builders. You may have some debris in your condensers - on the 0-10 DIY scale - about a 7 to clean them yourself. You could also consider a third radiator which will add overall cooling capacity to the system - probably not worth it until your approaching 250-275 on a fairly regular basis.

 

This is a common misperception. The operating temperature of a thermostat specifies when it opens. This impacts the warm up period on a cold engine. If it opens at a lower temp it takes longer to warm up the engine because it allows the cold coolant outside the block to mix with the hot block coolant sooner. The thermostat has zero cooling effect once the engine is "warmed up". All the cooling comes from the water pump flow rate and the efficiency of the radiators.

If you want to lower a hot engine's nominal operating temperature, improve the cooling system efficiency - clear blockages at the radiators, increase airflow across the radiators with more bumper openings or fans, or add more radiators to the system (3rd center radiator).

 

Look at your front radiators to see if there is any leaves/debris just to check but that temp is fine.

 

Nothing wrong with that temp. Especially if it's only after hard drives.

If it bothers you, as others have suggested, check to make sure your radiators are clean and/or add a 3rd radiator to drop a bit.

 

I disagree and don't discount your other factors. The setpoint is just a common way to represent the "cooling" ability and a not insignificant factor is the physical coolant flow rate through the device - think open more/flows more the farther the current temp is away from the setpoint - a PID device not solenoid (on/off) like.

 

Semicycler is spot on with the thermostat.

225 will remove the water from your oil. That's a good thing.

And modern oils are fine at higher temps than dino oils were.

I've seen my 2010 C4S PDK approach 250 on my best drives. I see no problem.

 

That temperature is fine, specially after spirited driving.

 

Spot on, there is so much misconception how a tstat works

 

To the OP: Your oil barely warmed up. Go drive!

 

You mean like it's exhibited by those guys at Flat Six and Hartech?

 

You really don't know what the temperature is unless you connect an OBD2 code reader/data viewer to the OBD2 port and read the coolant temperature.

If the radiator fans were on -- and not on because the A/C was on -- by my observation the coolant temperature was 212F or higher. If the fans were on high the temperature was 216F or higher.

Wtih my Boxster driving it in 116F heat in AZ -- or in lower ambient temperaturs but on a spirited drive if you know what I mean -- I've seen the coolant temperature reach 226F and stay there with both radiator fans running at high speed. The engine was just fine.

As long as the system is fluid and pressure tight, both fans come on when the coolant is hot enough both fans blow the same amount of air and the same temperature of hot air, and no warning lights come on the engine's just fine.

(If the radiator ducts are full of trash you can clean the trash out but my experience after removing "tons" of plant/leaf litter from my Boxster radiator ducts is this made no difference in the coolant temperature. There is considerable excess cooling capacity. (Another time my 2003 Turbo lost a radiator fan motor (the shaft snapped). The coolant temperature was fine and even the A/C worked fine -- this in 90F+ ambient temperature in the Fresno, CA area -- with just one radiator fan working.) The bigger issue with the trash is possibly shortening the life of the A/C condenser and radiator due to corrosion.)

I know some owners get all crazy with concern when the temp gage needle even looks like it goes over the 200 hash mark (or 180 hash mark on the older models) but I like to see my car's coolant gage needle up above the "180" has mark some. When I see this I know the oil's nice and hot (the "40" as in "0w-40" is the oil's viscosity rating at 212F so for the oil to be that hot or even hotter is the temperature the oil was designed for) and this helps to remove water from the oil.

 

I can't speak for them but I believe their reasoning has to do with the rate of warmup of cylinders vs heads and the temperature differential of these metals during the warmup period that lead to bore scoring in the m96/97 engine. Nothing to do with the overall cooling capacity of the system. And not related to the 9a1 engine of this thread.

 

+1

I believe that "true" oil and water temps run pretty close..... they virtually occupy the same places in the engine where temps are created.

My 2009 C2S oil temps jump in the summer and annoy me..... I gotta believe that is OK.... it is consistent across our cars and Porsche should have tested at least one of the cars before selling them (I hope)

I pulled the bumper and cleaned the radiators out of my 2000 Boxster S until 194K miles.... See pictures at bottom of page here: https://rennlist.com/forums/997-foru...diators-2.html
I worry too about corrosion caused by this stuff cemented in there... but never had a leak and after cleaning.... the coils at least looked good to me. BTW, I would occasionally vacuum them out throughout the life of the car.

Peace
Bruce in Philly