2002 Volvo xc v70 coolant leak mystery

[Austentatious07]

Hey there. Hoping someone will have some insight to a strange coolant problem I'm having. I have a volvo that is leaking coolant from somewhere after I go up big hills or long road trips, basically when my car is working really hard. The thing is, it's not a steady leak. I can go for weeks just driving around town with no leaks, then I'll drive up a big hill and coolant just dumps out. Usually somewhere from the middle right of my engine and you can't really see from where while I'm looking at my engine from the top. I've had 3 different mechanic friends of mine look at it and all of them just say, well, there's no coolant leaking from anywhere! ... I've had a pressure test done on the system and there is no leaks. But it's happened maybe 4 or 5 times in the last few months where I'll cruse up a big hill and boom, puddle of coolant under my car. Please help!!

[tmcmilli]

I have heard that portions of the OEM radiator other than the core are made of plastic. I do know for a fact from personal experience that this was the case with the radiator on my '1997 850 with 2.4 liter non turbo. That radiator developed a leak which initially only occurred when the engine was under load like when accelerating or climbing a mountain. The first couple of times it happened, some antifreeze sprayed directly onto the serpentine belt causing it to slip off of the pulleys.

It turned out I could see the antifreeze spraying out from a seam in the plastic portion of the radiator near the right or US passenger side of the car in my case, but only when I revved the engine by rotating the throttle linkage from under the hood to rev the motor up pretty good while watching what was going on under the hood. Then I could see antifreeze spray out from a crack that had developed in the radiator. Maybe you have a similar problem.

I wonder if the body of your radiator is plastic like mine was? Not the center cooling portion of the radiator. This would be the area of the radiator on either end of the radiator where it mounts to the car. I was actually quite surprised to discover on my car that this area was plastic.

Hope this helps,
Tom

[abscate]

Look for the white deposits from evaporated coolant around the engine. Check all around the hoses, heater hoses, turbo hoses (tough to see unless you remove the cover). The radiator reservoir often cracks on these cars too.

[oragex]

Quite common issue is the coolant reservoir or cap developing a small crack.

On my car, I noticed a random drop in coolant level. I believe it's due to a head gasket that has a small leak, causing coolant loss especially when pushing the engine some harder. Being a very small leak, all fluids are clear and don't seem affected.