New Radiator...

[Jeepwalker]

Well, I milked the old mildly-leaking radiator for a few yrs till she could go no more, and got real leaky! It was part of my coolant replacement process! Installed the new AC Delco radiator I bought a couple yrs ago back when they were available (one of my hoarded parts). Also replaced most of the rotating elements on the engine: new belt pulleys and new Alternator. The bearing had been running dry. The brushes had worn a groove in the armature, so perfect time to replace. She's dry and quiet up front now!!!

WARNING: For guys who haven't replaced the alternator.. PLEASE disregard what one you-tube self proclaimed 'expert mechanic' (doing the job the very first time) suggested ...which was bend the AC tube a lot, to remove the alternator out the top. He really bent that AC line! A good way to potentially screw up the AC. The easy way is to remove the fan shroud and fan (need a fan wrench), then the alternator slides out the front under the AC line easy as pie. No screwing up the AC.

 

[H3Hummer]

second that !!!! changed my radiator and alternator too , long time ago, and lucky me , i DID NOT follow the bullshit told on YouTube!!
Like Jeepwalker says , the right tools and the right way to go without damaging AC Lines !

 

[jcam]

I just finished changing the alternator, radiator (replaced with all aluminum and electric fan), water pump and thermostat. It started as just an alternator replacement but got carried away when I saw how easy access the thermostat was, and I bought the radiator a few years ago so figured I'd replace that too. And while I'm breaking the coolant system, why not change the pump too.
Anyway, I put an inline coolant temperature sensor in the bottom radiator line to actuate the fan. It's supposed to turn on at 190 and off at 165. I've read different opinions about which direction the coolant flows in the 3.5 but decided that it flows bottom(driver side) to top(passenger side) on the radiator. But now the fan runs for only 10 or 20 seconds at a time and the gauge is almost at 3/4. Can someone tell me, definitively, which direction the coolant flows in the 3.5L?

 

[Jeepwalker]

Most engines draw the coolant from the bottom of the radiator, and return back to the radiator (from engine) via the upper hose.

If it were the other way around, even being a little low on coolant, the coolant level would fall below the upper hose...and would starve an engine of coolant.

 

[jcam]

Most engines draw the coolant from the bottom of the radiator, and return back to the radiator (from engine) via the upper hose.

If it were the other way around, even being a little low on coolant, the coolant level would fall below the upper hose...and would starve an engine of coolant.

That's what I've always thought also. But the thermostat is on the bottom hose, which would be the return line, which doesn't make sense.

 

[Alpha X]

Can someone tell me, definitively, which direction the coolant flows in the 3.5L?

For what it's worth... GM named the upper hose INLET and the lower house OUTLET.

 

[jcam]

For what it's worth... GM named the upper hose INLET and the lower house OUTLET.

Thanks for the info. Would that be inlet and outlet to the radiator or engine?

 

[Alpha X]

Thanks for the info. Would that be inlet and outlet to the radiator or engine?

Sorry, I should have clarified. That applies to the radiator. Hose Radiator Inlet is the name of the upper hose (for both I-5 and V8), & Hose Radiator Outlet is the name of the lower hose (for both I-5 and V8). The radiators are the same for both engines as well, with a slight difference for the manual transmission which does not have the transmission cooler in the bottom.

 

[jcam]

Sorry, I should have clarified. That applies to the radiator. Hose Radiator Inlet is the name of the upper hose (for both I-5 and V8), & Hose Radiator Outlet is the name of the lower hose (for both I-5 and V8). The radiators are the same for both engines as well, with a slight difference for the manual transmission which does not have the transmission cooler in the bottom.

Thanks much.