Today I was stuck in I-5 traffic south of Vancouver WA. The outside temp(my car's outside temp gauge) was 98~105 degrees. My engine oil temp finally crept up to 232 degrees after many cooling fan cycles. Finally I got out of the blasted rush hour traffic and got her cooled down some. I run full synthetic oil. I tried to search this with the advanced search but didn't get much. Maybe I wasn't patient enough...or my search terms left something to be desired.
Is this a tolerable temperature running full synthetic oil on occasion? Here it is early June and we haven't hit our "warmest" weather here in the greater Portland area.

Thanks, Went

Oh, and I have a 1.5" Dewitts "clean" radiator, new hoses, thermostat, water pump.

 

what was coolant temp.

when my oil tep was hard to get down it was due to a clogged cat.

 

The highest coolant temp I saw was 335 degrees. The fans were coming on okay but I think there must be a bit of lag from when the fans come on and you start seeing temperature drop on the gauge. Each time the fans came on I eventually saw a two degree drop in the oil temp but each fan cycle saw the oil temp climb higher.

Went

 

Your oil temp is normally 20* hotter then the coolant after its fully warmed up. But if the coolant temp is 240* and oil temp is +260* while gong down the road, I'd be concerned. High oil temps are caused by high coolant temps or high rpms.

 

Those oil temps are fine, normal in summer traffic with stock fan settings.

The DeWitts should have knocked those coolant temps way down and dragged the oil with it as soon as you got moving.

 

Agreed, your oil temps are no problem at all. Synthetic can take some serious punishment before breaking down. I think Mobil is good for around 500F, so that'll never fail due to temps unless your engine is on fire, lol. I see 260-280 when having fun in the hills with the car, and I don't even flinch at those temps.

 

Okay, I'll not sweat it. The Dewitt's radiator did drag the temps down a few degrees each time the fans were on for a complete cycle. After a while they just kept edging up. Once I got moving proper the temps dropped down.

Thanks everyone.

Went

 

Did your Corvette's engine coolant really hit 335*? That is the highest I have ever heard of for coolant. Both your cylinder heads must look a bit warped by that I would assume. I hope it was a TYPO....

I don't believe it but if it DID hit 335* then you have some sort of problem. 235* I could live with but 335* is just too hot for a gasoline powered automobile engine.

Most automobiles have a pressure cap on the radiator that allows the anti-freeze to keep it from boiling up to 260*, After that you are on your own.

I have a High Compression 427 in my 1968 C3 and it gets hot using conventional water and anti/freeze (70/30), I have seen 260* coolant temperatures before but not anymore. I have a "non-pressurized" cooling system using EVANS NPG as the coolant. It handles the heat a bit better than the water did and won't boil until it reaches 369* F. It does a great job getting the heat out of the engine I have built and last forever so you don't have to change it every few years. No more pressure in the coolant system reduces the wear and tear on the hoses.

Keeping your radiator clean is critical to getting cooler temperatures. The other important thing is the air dam that came on these C4's needs to be there if you want to stay cool. I use A.C. Coil Cleaner for cleaning my aluminum devices as it removes all the corrosion. Less corrosion and you get better heat transfer. I am a big believer in replacing the thermostat and radiator cap in addition to the standard coolants every five years so they won't strand you. A bad radiator cap will not hold pressure and the car will over heat easily.

It is that hot in Washington State? We are normally like that but it has been in the mid-70's most of today here in the Washington D.C. area. Must be glowball warming....

Good Luck and get that Corvette to cool down a bit!
Best Regards,
Chris

 

Hey Chris, you are right! My post should have read 235 degrees. My shaky finger must have tapped the "3" twice. I've got to proof read my posts a little closer....We are warmer here in Oregon right now. Portland was officially 95 yesterday and it was supposed to a few degrees warmer today. I live about 20 minutes west of Portland, OR.


Went