Oil temp 25 degrees higher than water

[robertwilbanks]

'86 is running warm to start with. The thing that is bothering me is the oil temp is running at least 25 degrees hight than the water. If water is at 210, oil is topping 235 the water hit 248 driving up the mountain and the oil hit 300. I am using Mobil1 synthetic.Anyone have any ideas why.
Thanks.

 

[robertwilbanks]

should have added:
I just put in a 160 thermestat, new hoses, pulled the radiator and cleaned it. I checked the oil level and pressure is also ok.

 

[1986coupe]

Have you cleaned the rad? If you have changed the t-stat and it is still warm then clean the rad. There could be alot of leaves and other stuff in there that is keeping the car warm. You would be amazed at what can get in there. The very least you should do is spray water from the back of the rad to the front to get some things out but you might want to remove it to get everything out from between it and the condensor.
If the engine is warm then the oil will be warm. Cool the car first then the oil.

 

[Vettefan87]

I agree with 86coupe, you will be able to tell if it is clogged up, the coolant temp should drop when you are driving on the open road especially with a 160 stat, another question, is the main radiator fan working? if not that is your problem.

 

[robertwilbanks]

The fan works, the water temp will cool down and the oil will cool down also. It is just the oil runs hotter than the water. The climb up the moutain is 5000' in 18 miles so it is a fast climb. Normal driving keeps right around 200 for the water.

 

[Vettefan87]

To my understanding the oil will always be hotter then the coolant, unless you have a oil cooler like i do then they stay pretty close together. My brothers vette on the way to Auburn for the cruise ran coolant 164 oil about 210. He has the thermo master chip which kicks the main fan on at 175, so if he sits it will still not get very high, but stock it kicks on at 220 I think. his spicked like yours did to about 235 for the oil, and it was the fan not running. I am just guessing but have you opened the cap in your radiator to see if you are getting good circulation of the coolant? maybe a water pump problem or a cloged radiator.

 

[ErnieN85]

The spec for L98 is oil 30 over coolant so unless you have a oil cooler that is what it will eventually reach. if you do a lot of mountain driving or track time an engine oilcooler is a real good investment (if you plan on keeping this vette)

 

[WNH]

My oil & coolant stay within 10 degrees of each other,
I think this is normal.

Maybe your oil temp gauge is malfunctioning.

 

[Vettefan87]

Could be, but he said his water temp was around 243, is that normal? before i got my chip my car would never go past 225 even in traffic.

 

[SPANISHVETTS]

'86 is running warm to start with. The thing that is bothering me is the oil temp is running at least 25 degrees hight than the water. If water is at 210, oil is topping 235 the water hit 248 driving up the mountain and the oil hit 300. I am using Mobil1 synthetic.Anyone have any ideas why.
Thanks.

The climb up the moutain is 5000' in 18 miles

I have never seen water temps over 220º even after prolonged stop and go traffic in 100º+ summer weather.(back when I had water in my Rad…Now I run it dry and never see 195º)

Synthetic oil performs best around 225º and can stand 260º temps for extended driving periods however 300º for 18 miles of driving could break down even Mobile 1. You should change the oil ASAP.

I think your problem is the water temp…get it down and the oil should cool down with it.