C20 Oil Cooler/Rad Tied Together?

[44SAA]

My coolant has been mysteriously disappearing. I’ll top it off, and shortly after half of it is gone. No leaks on the floor nor have I experienced overheating. Question: is the Oil Cooler somehow tied into the HD radiator? I ask as I was wondering if this may explain where my coolant is going. Radiator and oil cooler are both 42yrs old and OEM. Pic of culprit and future owner, if it’ll make til he’s 18… Thank y’all

[Dead Parrot]

Most oil coolers don't run inside the radiator. But IIRC, the 6.2 diesel does have a oil cooler inside the radiator. Even if yours is gas, possible a PO installed a diesel radiator for 'reasons'. Even then, oil pressure is almost always higher then water pressure so the normal result would be oil in the coolant.

White smoke in the exhaust can be a sign of coolant leakage.
Most water pumps have a weep hole to allow seepage to escape. That can lose a lot of coolant if the pump is near EOL.
If it has AC, there is a condensate drain on the engine side. A leaking heat core might be loosing coolant via that instead of the cab floor. But if the core is leaking, you should smell coolant in the cab.

The future owner sure has the 'Joe Cool' look down.

[MJN]

Your transmission oil cooler is integrated into the RH radiator tank- if you have an automatic transmission. Easy way to see if you are mixing coolant and transmission fluid is pull your transmission dipstick- if it is pink and foamy then you have water/coolant mixed and need to drain and flush all the trans fluid out. Have you checked the engine oil for coolant? Possible leaky intake gasket or head gasket? Any white smoke out the tail pipes? Any wet spots on the radiator itself? You mention you top it off and shortly after its half gone, are you topping off the overflow tank or the radiator? Are you topping off and then driving with engine up to temp and then after it has cooled off half is gone again?

[44SAA]

Just yanked out the rad. It peed out some ATF

[44SAA]

Took to rad to old school repair shop- and it’s toast. Anyone recommend a nice plug and play replacement? He sells a copper/brass for $300. Saw the aluminum Chicom variety for 1/2 that.

[72c20customcamper]

Have you checked the transmission fluid antifreeze will kill it in short order

[44SAA]

Just changed ATF last week- looked good

[Corts60]

Originally Posted by Dead Parrot

Most oil coolers don't run inside the radiator. But IIRC, the 6.2 diesel does have a oil cooler inside the radiator. Even if yours is gas, possible a PO installed a diesel radiator for 'reasons'. Even then, oil pressure is almost always higher then water pressure so the normal result would be oil in the coolant.

White smoke in the exhaust can be a sign of coolant leakage.
Most water pumps have a weep hole to allow seepage to escape. That can lose a lot of coolant if the pump is near EOL.
If it has AC, there is a condensate drain on the engine side. A leaking heat core might be loosing coolant via that instead of the cab floor. But if the core is leaking, you should smell coolant in the cab.

The future owner sure has the 'Joe Cool' look down.

X2

The 5.7 diesel and 6.2 diesel radiators had internal trans cooler in passenger side tank and internal oil cooler on driver side tank.

[cadillac_al]

You would never get that much coolant into the cooler. Maybe a bad cap? My Jeep had a slow coolant loss until I finally saw the steam show.

[44SAA]

Picked up new rad and tackling some “while you’re in there stuff.” Corner of fan shroud has been broken, welded the plastic with soldering iron. Feels strong, curious if it lasts. Wiring loom- before heading to the parts store and picking up some Chicom loom, is there a manufacturer anyone can recommend? Seems like I recall GM loom has a blue line running through it. Thank y’all

[Dead Parrot]

For your shroud, use the largest washer that will fit as a load spreader.

No clue on chicom loom. So many things from there seem batch oriented. One batch(shipment) will be excellent. The next one 6 months later will be crap.