I just had a new Ron Davis radiator with oil cooler installed. The shop used a thermostatic valve to open flow to the oil cooler in the radiator after oil reaches operating temps. This appears to begin opening at about 180 degrees and to be fully open by 200 degrees oil temp.

Oil pressure cold is 55 lbs. Warmed to about 175 degrees, the pressure is still 45. These are at idle.

Driving environment in Phoenix AZ today - 110 degrees ambient, driving with A/C on. Coolant at 200 degrees at 65 MPH and oil temps at 219 degrees. In stop-and-go city traffic for only 5 miles, coolant went to 232 degrees and oil rose to 225 degrees.

Note, with the stock 1999 radiator, freeway driving with the A/C on yielded 196 for coolant and 220 for oil with no cooler.

Problem - why am I not seeing improvements?

BIGGER Problem - once fully open for flow through the oil cooler, oil pressure drops to about 20 at idle and does not go above 30 under throttle. It dropped to 16 psi at idle while city driving.

Can anyone shed some light? The only thing I can think of is that they used lines to the oil cooler that have too large an inside diameter, so pressure is dropping.

Note - oil cooler bypass is mounted by the filter, radiator is clean and no debris anywhere. Fans are working properly.

Thanks in advance for your help. Paul

 

Instead of asking here, why not contact Ron Davis guys or the people who installed it ? They should be more knowledgeable than any one else.

 

I will tomorrow, but it is Sunday. I was hoping that, maybe, someone had similar experiences that I can learn from.

 

I ran the RD radiator with oil cooler and remote oil filter without the thermostatic bypass valve for several years. Oil and coolant temps were about 10 degrees cooler before I installed the valve. Oil pressure also dropped a little after the valve installation but nowhere near as much as you are seeing. Make sure the valve is installed correctly in the oil lines. They work by shunting 15% of the oil through the cooler until they get to their opening point and then 85% goes through the cooler. It never completely shuts the flow off in either direction to keep air bubbles from getting into the lines.

Bill

 

Bill - thanks for the info. I've used the RD's twice before and never lost more than about 5 lbs pressure. This has me stumped. Long time - no see! Hope all is well.

8VETTE7 - I will post the findings and I hope there is some simple fix. Or, the oil cooler is being completely bypassed tomorrow afternoon until a solution is identified.

 

i would not bother with oil cooler T stat. i do not use and i am in phoenix and i have no oil pressure changes at all ! plus your water will keep your oil warm

did you change your water T stat to 160 and lower the fan switch temps??

fans make huge difference !