GreggyG

I had my tbelt and water pump done and lexus said that my radiator had a little seepage in the top right corner of the radiator, wanted to charge me $900 for a $400part and the labor was already a non issue because they took it off to do the tbelt and water pump. They also told me I needed $1000 in cv boots but an independent shop put new small clamps on and refilled the boots with grease for $35.

I never had any overheating issues so I was skeptical. Anyway, since I came back from lexus 2 weeks ago, the reservoir went from midway between L and H down to low. I filled it 1/2 of the way last night, drove it a little and it's down to Low again in the reservoir. I don't see any signs of leaking anywhere. I filled it to 3/4 now and let it idle until the gauge got to normal operating temp, the level raised to a smidge over the F line. I will drive it around today and see but what if I goes down to L again? I took off the fill cap of the radiator and it seems some coolant started to come out the top a bit so I didn't open it all the way (this was after it sat and I filled the reservoir this morning, not after started it.

I can't tell if it just needed to be topped off overall or if something is going on. Any thoughts or suggestions as to how to test or what to look for? The seepage at the top appears to be just a tiny bit of crust, nothing new or nothing major.

IanB2

Coolant that's slowly seeping from the rad will dry on a hot rad pretty quickly. You may never see drops on the floor, but that doesn't mean you don't have a problem. When I had my timing belt/water pump service done there was signs of pink coolant on the fins of the rad, so I had it swapped for a new one at the same time.

if you're hesitant to spend the $$, keep a real close eye on your overflow levels and coolant temp gauge for a while. If it doesn't level out and stop consuming, then you've got an ongoing issue, and the problem is you never know if that rad is going to give up completely at some point and leave you stranded.

GreggyG

Thanks, is there any other place it could be leaking from to consider? What are the chances of replacing the radiator and it still having a leak?

IanB2

Ya, there's lots of places a cooling system could leak. Water pump could be seeping, hoses could be worn out, head gasket could be toast, etc. The fact you have signs of seepage on your rad would make that the 1st place I'd look though.

GreggyG

I just had the water pump changed, so it couldn't be that. I guess it could be hoses as well but I'm doubting the head gasket as the it runs fine and I don't notice any smoke.

chiph9

When my radiator started leaking, it was at the top-right corner. It formed red crystals from where the coolant dried from the heat.

They shouldn't have charged you much additional labor for replacing it if they were already doing a timing belt.

When you get it replaced, ask for about a half-gallon of pre-mix coolant to take home. Afterwards the system will burp air and you'll need it to top-off in the overflow tank. Or just go by the dealer again and they'll do it for you.

Chip H.

GreggyG

here is another symptom. It was filled fully on sunday, I drove around a little came back and everything was still full. I let it sit for a while and checked it, still full. Just let it sit for 4 days while I rode the motorcycle and I checked it this morning before I started it and it was down 1/4 in the reservoir. Isn't that weird because I don't think the system will suck anything in when the car is off for days. I wonder if it's a small leak or seepage from the reservoir tank, though I don't see any major evidence of that. What could make the reservoir go down after the car is off and just sitting for days?

techrep

Go barrow a cooling system pressure tester at your local auto parts store and preform a cooling system pressure test...you will see were it's leaking from, unless it's internal ...

GreggyG

Thank you for the suggestion. Am I correct in assuming that the system cannot and does not suck in coolant from the reservoir after the vehicle is off for a couple of hours? If that is the case, then wouldn't it make sense that there is actually some form of a small leak in the reservoir?

chiph9

When the engine and radiator cool down, they will indeed pull fluid from the overflow tank.

Chip H.

IanB2

As a hot engine cools is when it pulls from the expansion tank. It should stabilize once the system is full though. If it's always drawing down the expansion tank every time you run it (once it's had a chance to work any air out), you've got coolant escaping somewhere.

chiph9

When I had my radiator replaced, it took about 3 days for the coolant level to stop dropping as it burped out air.

Chip H.