Trying to fix my Dad's 2008 TL 3.2 Base automatic. A couple of months ago transmission cooler inlet corrosion required me to install an aux cooler, thereby bypassing the internal unit. No problem. However, I did notice while working on it that some coolant leaked from I don't know where though clearly somewhere from the bottom of the radiator, not a hose. It was a slow dribble so I filed it away that we'd need a new radiator. Leak worsened, no surprise, so I bought and installed a new Denso unit though couldn't find new hoses nearby or quickly so I left old hoses because they looked really good.

Fired it up and all was well until it got warm when a leak started up from I don't know where, but clearly the bottom. Found and replaced both hoses thinking there was a pinhole leak in the lower hose all along. No problem. Leak persisted. Grrrr.

I examined very closely and am seeing coolant pool at the bottom crimp of the new radiator (e.g. top of the bottom tank).

Ordered a replacement Denso from the same place. Before I install it, is it just a coincidence that I'm seeing a leak from somewhere I can't see again and again, or have I missed something all along? To me, there's no way that coolant could pool at the top of bottom tank unless it's coming from the radiator channels or top hose. Hose and connections are dry. Nothing squirting from the engine. The sensor is tight as is the petcock valve --though those are below the pool anyway. The dribble has a frequency where a few grams of fluid will dribble, then stop, and do it again 20 seconds later. Like it's leaking from the radiator channels or bottom crimp, filling up on top of the bottom tank, then giving me a few grams of dribble before taking a bit to load up before it dribbles again.

If it's a coincidence and therefore a leak in the new radiator? Is it wise to install another Denso made in Indonesia again?

My Dad said maybe I should take it to someone that knows what he's doing, but I think I can do this.

Does anyone have any new thoughts or experiences while I wait for the replacement unit? If so I would very much appreciate your time in cluing me in.

 

got any pics?

 

Sure. Added a shot of the pool I mentioned on the top of the bottom tank. In this picture look at the blue puddle at the bottom of the radiator core to the right. Leak right?

 

Anyone have thoughts on this?

 

did you leave the radiator petcock drain slightly open?

 

LOL! No sir, I checked that before installation and then again after I noticed the puddle. It is below the top of the bottom tank anyway, so that couldn’t be it.

 

Very strange, but leaks can drive you crazy. We feel your frustration, especially since you appear to have taken all the right steps. Have you considered having a pressure test performed on the system? Your comment that the leak seemed to reappear after the car warmed up could mean heat (thermostat) related, or pressure related. The PT test might help you rule out or point to a pressure related issue.

 

Yeah thank you. I going to fashion a pressure tester from the brake bleeder that I already have and see if I can visualize the leak. I’m sure it’s coming from the core but I hope to find out unequivocally.

 

Pressure test and go from there. I hope it isn't the rad, but if it is, it could have been damaged in shipping. Happens all the time...