change your radiator cap yet?

 

Yes, they put a new one on when I first took it in a couple months ago.

 

I have had the the leak that occurs when the car is parked after driving. (v50 2.5t) It was a failing water pump. The seal that prevents the coolant from going past the shaft starts to fail and coolant can get past and it drips out the weep hole. When the car is turned off and the pressure remains, the seal shrinks a little from cooling down and the pressure forces the coolant out. I started noticing a small circle of coolant on my driveway. Then I found the car leaked quite a bit of fluid overnight. Soon after, the car pissed a bunch of fluid just when I parked and went into a store. A day later, it just starting pouring out while driving and I had to pull over immediately get the car towed home. I believe it was about 2 weeks from first signs of the leak to total failure of the water pump seal. If this was your scenario, coolant would be coming from the water pump weep hole, which is under the timing cover. However, where you would see it would be on the bottom of the engine on the rear passenger side where it would then drip onto the splash guard under the car and then drip to the ground near the passenger front tire. You can verify the water pump leak by pulling the timing covers, passenger front wheel and wheel well plastic guard, and inspecting the water pump.

Are you sure the leak you circled in your picture isnt coming from higher on the engine and just dripping from this point? I dont think there are any parts of the coolant system on the bottom of the engine.

Since coolant is such a thin fluid, the leaks are usually easy to trace, just follow drips upward until you get to the top.

 

A note on this failing water pump seal, do you see "grit" or "dirt" in the coolant? When my water pump seal/bearing started to die around 160k miles. ( 250k Km? ) I could visibly see grit in the coolant tank.

but check 1: Coolant Tee, just to the right of the engine, see if it is cracked at all. they are prone with age. its a PITA but reasonable replacement at home with the right hose clamp tool.

check 2: Thermostat, can crack with age.

check 3: pretty much all other hoses. from where I can guess form the one image I would guess the leak is from the frontal area of the engine and flowing backwards, could be wrong. also check the hoses that run from the engine bay into the firewall, just to the left of the battery.

removing the airbox to check the coolant hoses can be tough but it do-able with patience simply because it is a excercise in geometry. There should be videos about how to tilt it left down, right up and out.

 

Was the cap replaced with a genuine Volvo (Ford) cap or aftermarket? I have had issues with aftermarket (Stant) not holding proper pressure and coolant boiling out of the tank at normal operating temperature. Go with Volvo or Ford cap.

 

I'm on the same thought train as unodos96. My first guess is the upper radiator hose. The one with the plastic tee fitting in the middle. I had a leak that a shop "fixed" by replacing the water pump, but the actual leak from the hose was never addressed. Get access to it and see if there's any white residue from dried coolant on the hose.

And while you're in there, replace the thermostat for peace of mind.

 

Replace coolant reservoir if it is old. Needs replacement anyway. Can leak out of the overflow opening. This is easily missed.

My C30 had radiator leak in plastic surround housing and was not seen until the radiator was removed. Glück

 

Coolant reservoir was my issue. Small hairline cracks, and when it was warmer out they expanded and did not leak, in the winter they contracted and leaked until the engine bay got hot. Took me a while to find it. Super easy replacement.

 

It seems that the radiator plug is metal, I would recommend torquing it to 7.5-11.5 ft lbs if u have a torque wrench.