KhanTheMon

I've been having a lot of problems with my 06 LS and finding a working radiator for it. I had a coolant leak from the radiator so I ordered a DENSO radiator from RockAuto and swapped it only for it to be leaking coolant. Then got a replacement part from RockAuto, another Denso radiator...and that one was leaking too. Now I am onto finding a third radiator for my car, definitely will not be purchasing a denso radiator.

Any recommendations on good aftermarket radiators?

LeX2K

Leaking where exactly? I've installed dozens of Denso rads never had a problem. Admittedly more and more are being made in China doesn't inspire confidence. Roll the dice and get a different brand.

KhanTheMon

It is leaking from inside the radiator somewhere, I don't see any visible leaks and there is only two connection points for the coolant upper and lower rad hoses. I just see coolant dripping underneath my car from the radiator fins on the left side. I will just see it drip and the upper hose is dry so it's not leaking from there. Has to be the radiator leaking.

bradland

There are 3 coolant ports on the radiator, you’re forgetting the small hose leading to the overflow reservoir. The reservoir basically piggybacks to the backside of the radiator so if it’s leaking it could appear to be coming from the rad. Check the reservoir and the hoses attached to it. Also, if you have overfilled the system surplus fluid will exit to the ground from the reservoir. Probably a good chance both Denso rads we’re just fine.

KhanTheMon

yes I remember those forgot to put in my initial post. I did fill it up and attach the small hose. It’s leaking from along the left seam of the radiator. If it were from the overflow tank it would drip towards the middle.

LeX2K

Looks like you need a different brand since you're certain the upper and lower rad hoses are not leaking.

bradland

Several things to consider here-
It is leaking from inside the radiator somewhere, I don't see any visible leaks...
I just see coolant dripping underneath my car from the radiator fins on the left side.
I will just see it drip and the upper hose is dry so it's not leaking from there. Has to be the radiator leaking.
You don't see any visible leaks but you're convinced it's the radiator...? Where did each of the 3 rads leak from? The same general area? If you didn't have any of them pressure tested you are simply assuming.

Reservoir-
I did fill it up and attach the small hose.
If it were from the overflow tank it would drip towards the middle.
The reservoir is not supposed to filled to the top. As long as it's filled to the blue line you're fine. If you filled it to the top most of the coolant above the blue line will be expelled to the ground. If this were to happen when the car is stationary (not running) yes it would exit in the middle (green line). Surplus coolant exits when the car is running and hot so conventional logic does not apply. When running and hot the engine compartment is basically a wind tunnel. Coolant is easily sprayed in a variety of directions. Good luck tracing a leak with 2 fans running and a serpentine belt spinning.

The LS cooling system is overengineered and very forgiving but the external reservoir is its Achilles heel. The most common mistake is filling the reservoir then subsequently seeing fluid and assuming it came from the radiator. The 2 hoses attached to the reservoir become brittle and hard with age. This causes the overflow system to do funny things. Don't fill the reservoir, the system fills it when the car is warm.
Have the cooling system pressure tested, it will likely save you more headaches...

ls430w140

The only recommendation that I can give is Denso from Rockauto, preferably one made in Taiwan. Your case is likely (needs a diagnostic obviously) is referring to plastic ventilator attachment to a radiator that is prone to leaks through plastic or rubber hoses.

Lzam

Yeah, I would say the chances of the radiator leaking in the same spot is nill I would have the system pressure tested.