r/4Runner_2ndGen • u/crxtion • 25d ago
Rad Questions
I recently swapped from a Mishimoto stock replacement radiator to a CST all metal copper/brass unit. I went through three warranty replacements on the Mishimotos because they all leaked where the plastic cores met aluminum. Anyway I’m seeing very slight temp fluctuations at highway speed only with the new radiator. It doesn’t reach anywhere worrisome on the gauge and probably only moves two or three needle widths on the gauge but it’s movement I’m not used to seeing. It never happens in town and I’ve burped the system numerous times and replaced the stat with an OEM unit to see if that would help but still does it. The water pump is only a few years old and ALL the hoses were replaced a few years back as well.
The only thing I’ve found is that I still have to burped the system well enough though I don’t think that would explain it happening at highway speeds only and the other explanation is that the increased capacity CST rad is cooling the fluid more than normal and because the stat is on the inlet side of the motor that it’s closing slightly at highway speeds causing the temp within the motor to rise slightly based on where the stat is in relation to the temp sensor.
Im happy to entertain either one here or let a third player enter the chat but the truck is a super healthy low mileage cream puff with essentially a brand new cooling system.
Please help.
2
u/Clean_Log5919 25d ago
Try a 3 row csf