[Jayjayson11]

Here's the thing. Just got my 2003 Pilot EX-L with 238xxx miles for a steal at $700. She's not pretty but runs great. The only problem I'm finding is the coolant is leaking out but I'm not seeing where. I've been reading around the site and see there's an issue with coolant leaking into the ATF. How do I even know if this is a problem? There's no coolant smell, it's not over heating, but I've put in a full bottle of 50/50 mix 2 days in a row and I definitely have not seen that much fluid on the ground. Should I just replace the radiator and change the ATF?

 

[boom]

No, you should get under there and identify the location of the leak, or get the vehicle to someone who can.

 

[plplplpl]

tl;dr: Yes.

If it otherwise runs great for $700, this insurance makes it a great deal. Check for a "pink milkshake" coolant color as a sign of ATF infiltration. But yes, it's worth it to change that rad sooner rather than later even if you don't have the pink milkshake but just a mystery leak. Change the hoses and thermostat while you're in there. Get a Denso rad at Rockauto.com.

Further reading:

Replace radiator as insurance at 100K?

How often are instances where a coolant leak from the radiator contaminates the transmission fluid and results in needing a new transmission? Is this really rare, or is it worth spending $500 to replace the radiator as insurance? We just purchased a 2005 Pilot with 97,000 miles on it, so I'm...

www.piloteers.org

 

[huntertn]

When you say you are not seeing that much coolant on the ground does that mean it does have an external coolant leak?

If it does have an external coolant leak but you are having trouble finding it, the easiest thing to do it use a pressure tester. Around here, you can do the “loan a tool” thing at many auto parts stores - Autozone, Advanced, Oreileys,etc. Just ask for a radiator pressure tester. It lets you pressurize the cooling system and narrow down the location of the leak without running the car.

 

[slipjohn1]

Check your exhaust, you may be burning it which means head gasket. If it's not leaking, it's probably cooking. If you have a lot of white exhaust and it smells kinda sweet, you may need a head gasket. That's a lot of miles.

 

[road2cycle]

Yeah, pink milkshake or leaking head gasket were my first two thoughts. It’s concerning that you’ve filled it with two bottles (gallons?) of coolant over a two day period. That is pretty much the capacity of the cooling system that you’ve replenished. Something is wrong and I would investigate before driving it any further.

 

[giwan1259]

Here's the thing. Just got my 2003 Pilot EX-L with 238xxx miles for a steal at $700. She's not pretty but runs great. The only problem I'm finding is the coolant is leaking out but I'm not seeing where. I've been reading around the site and see there's an issue with coolant leaking into the ATF. How do I even know if this is a problem? There's no coolant smell, it's not over heating, but I've put in a full bottle of 50/50 mix 2 days in a row and I definitely have not seen that much fluid on the ground. Should I just replace the radiator and change the ATF?

It is most likely a slow leak coming from the drivers' side. Its the connection from the radiator and cooling line to the engine. At least that was the case on my 2005 Pilot

 

[gifty74]

After the engine is up to temp and you are sure the thermostat is open, shine a light down at the base of the radiator where the aluminum bellows section meets the black plastic. I have an '04 and that's where mine started leaking from (around 200k miles). I thought it was the hose clamp on the hidden lower main hose at the radiator connection (that leads coolant back to the motor) but found the metal to plastic connection was the failure point. Not easy to see, use a very bright light and view from the top down.

Not a simple job, but I did do it myself and has been great since.

 

[giwan1259]

Agreed. I have an 05 and that connection is the spot. The leak can be extremely SLOW