Austrian Vette

I had my Vette for a spin as we had a sunny warm day.

On the highway the oil temp climbed relativeley fast.
After 5 minutes of driving with about 110mph I had 235° oil temp (still climbing, but I was at the exit and left).
But the coolant didnīt get over 195°

After leaving the highway the oil temps came down to normal (about 204).

I have the breathless 173° thermostat and usually have the fans programmed for that. But I now have the powerprogrammer deinstalled as I will put off the PCM to send it to Chris@ Speeddemonmotorsports (exchange!, new PCM is here, yet). So I have the fans not programmed. Can it be that??
I donīt see higher temps in town traffic.

I do not see higher temps in traffic, but only on faster highway speeds.
I do see hotter temps sice I have the tranny oil cooler sitting in front of the radiator, but never that high and that fast climbing??

Hope that anyone can tell me more.

Michael

Bob Lineman

two things will effect oil temp. Age of the oil and RPM. The coolant temp is really not directly affected by the oil temp. Higher the RPM, higher the oil temp.

Also, change it and see what happens. :)

Austrian Vette

But if the engine gets hotter then the water temp shoud raise also??
Can it be that the engine temp clims to lets say 240 or more and the water temp is still about 195.

Itīs about 50° outside, so is it normal that the oil can climb to 240 or more on a constant 110mph run.

Can the engine overheat with the water temp not going over 195??

Michael

rwj383

Michael, terrible things are not going to happen at 235. especially if you dont stay up there for seriously long periods of time. yes, the oil will start to break down and create HC' s faster the higher the temp, but, i dont think you're in the crucial Danger Zone. yes, oil temps can get much higher than your coolant temp. this one of the reasons we have to change oil in much faster time intervals than coolant. simply changing the oil will actually help keep the temps cooler. i wouldnt be surprised if after you changed the oil that the temps would stabilize ~220F on the same run at the same speed....

Austrian Vette

Iīll testdrive the car on the highway tomorrow and look if the engine temp climbs above 240+ or stops there.
If it goes over 240 I think thereīs something wrong as I havenīt seen that temps even on hot days (now itīs cold outside) and didnīt see more than 235 on much longer runs at 110mph and (much) more.

I cannot say for sure if I left the car in 3rd gear (coming out of town) :conehead on that run, as I was very unconcentrated. That would be a reason for the temp to climb.
110mph in 3rd would be like lot more mph in overdrive. :troll
But.... no , I cannot be that stupid and forget shifting???

Iīll see tomorrow.

Michael

jetskifast

If you are using Mobil 1, oil will not start to break down until over 450 degrees. http://www.redlineoil.com breaks down at even a higher temp.
235 oil temp is nothing. At Bragg-Smith we ran their cars at 300 degree oil temps all day long.

Austrian Vette

Itīs not Mobil One and not Redline.
Iīm not sure what brand it is, but I know itīs 10W40.

But is it normal to see that high oil temps at that low outsidetemps???
I think I didn`t read that high oil temps bevore?!?

Michael

jetskifast

If you are running your car hard, you will see high oil temps, no matter what the outside air temp is. Stock C5 does not have an oil cooler to be cooled by outside air.
Cooling system does not directly cool oil. You have motor parts which never see any cooling form your cooling system, such as bearings ect. High RPM and load produces heat on internal engine parts which will be transfered to your motor oil.

Austrian Vette

Thanks for the info, I appreciate it a lot!!!! :cheers:

I only worry as I didnīt have seen that temps when I droce the car about the same highway in the moning (at about 90mph) and on the way back (110+mph) I saw that temps raiseing relativley quick.

Iīll go to test it tomorrow, how far it climbs at that speed.
And see if it only has happened bacause I may have left the 3rd gear in on todays run :conehead

Also if there would be a problem , the engine would not cool down emmediateley after I let off the gas and go 60mph???

Michael


[Modified by Austrian Vette, 8:38 PM 1/30/2002]

carpe dm

They are right; it sound fairly normal for the driving you described. Should be no problem. The radiator is mostly dedicated to the coolant (some ATF cooling if you have the A4) and should always be cooler than your oil. I get 235 here in the desert often, particularly if I drive at the speed you are used to! :jester :smash:

MitchAlsup

Just as a point of reference, the oil in my Vette gets hot (>220) anytime I run a little hard, but doesn't get too hot (280+) unless I am doing insane things.

On the other hand, cruising in my F355 at 60 I have a oil temp of 190, and cruising at 120 it drops to 170, cruising at 140 it stays at 170, and I haven't been able to get it over 200 dF. Corresponding water temps are 190, 170, and 175. Therefore, I jump to the following conclusion, the Ferrari has a better* oil cooling system than the Vette and a better* water cooling system than the Vette.

Better*: means a better match to the performance envelope of the expected use of the vehicle.

molon labe

10W40?? i'm using what Chevy recommends - 5W30.

Elk

Michael:

Your experience appears to be normal. Oil temperature is almost always higher than the water temperature.

In general driving around town and on the freeway on a 70 F day I see water and oil temperatures at 192-194.

However, if I drop it into third or fourth gear and floor it, the oil temperature quickly rises.

On the track, the water temperature remains fairly steady, but oil temperature rises to 275 or so. I try to keep it under 290, but this simply my personal limit on what I like to see.

BTW, I spent a year in college attending Universität Salzburg and studying music at the Mozarteum. A beautiful city and a magnificent country. I just wish I remembered more German. :)

Ehrich

ChrisB

235 is probably on the high end of normal. If you aren't using a synthetic oil I would probably consider switching. If the oil temps get over 250 or so - or if you plan on road-racing, etc. you might consider a separate oil cooler. I would get one with an inline thermostat or add one to reduce wear on initial warm-up though, as well as to maintain highway oil temps.

SwissVette_Joe

Michael, hi,

late but better than never, I want to give you some supplementary information about the actual setup in my A4/3.15. Motiv: engine cooling (oil and coolant). May be you would consider my features as a possible cure to your actual problematics and give it a try. Here we go (as I wrote in an earlier reply to a comparable topic):

Until I got the HPP3 PLUS a HT 160°-Thermo, I detected about comparable behaviour with oil- and coolant-temps rising as you are describing....

As we do not have any "official" "speed-tracks/1/4-mile runways" (well, be creative....... :yesnod: :yesnod: :smash: ) here around in Switzerland, but lots lots lots of amazing but quite demanding "Alpine- and Blue-Mountains" roads, I wanted to give the HYPERTECH-route a chance. Conclusion: PERFECT....a total win-win situation.:smash: :smash:

After these 2 Mods (soft- and hardware), my oil- and coolant-indicators stay as glued at:

COOLANT => 85°C // 180°F plus/minus, independent of OAT
ENGINE-OIL => 99°C // 210°F plus/minus, independent of OAT

After such success with the new found engine readings, I definetely forgot to project any install of an oil-cooler. However, an engine oil-cooler would add some little supplementary engine oil qty as a great advantage.

With beginning of winterseason 2001, I was initially planning to exchange the 160°F-Thermo to the hotter 180°F-Type. But with the some first cool to cold days during last decembre and this january as well, to my real big surprise, the usual temps readings from summer did not change in general. So I drove now all the wintertime until actual without any specific changing of the above mentioned setup. And for sure I shall let it as is....it's starting to get warmer.

However, to optimize critical engine lubrication under enduring heavy load on hot days (enhancing wear- and heat-protection in the bearings and cylinders), I systematically use an SAE 10W-40 weight Oil (car integrally RED LINEd, you go figure, from front bumper to the rear one), PLUS one bottle of R-L WaterWetter in the Coolant mixture. My coolant-mixture is actually at 40 : 60 DEX-COOL : DESTILLED WATER => some less DEX-COOL quantity to further assist heat transfer out off the engine.

So this orangeish cocktail serves no hassle down to -15°C//2°F, following my test equipment. Had no problemos at all, and actually it looks as the worst part of winter just said good-by........

Joe.

wtknght1

That's really nothing. I race my Z06 consistenly and have had temps go to 295...with this real old cooler I was using too. I am now using an SCCA T1 Legal cooler and can put it together for you.

See my other post: http://forums.corvetteforum.com/zerothread?id=229885

Give me a shout if you're interested!


[Modified by wtknght1, 3:39 PM 1/31/2002]

Austrian Vette

UPDATE!!!

I did some runs again and the temp climbed and climbed.
So I decided to look at the thermostat.
I have a BPP thermostat installed.
I changed to the stock thermostat and gess what.........
On one hour at 120mph I never got over 215°F.
The BPP thermostat was not fully opening.

FIXED!!

Michael