Brutus213

hello, second time lexus owner. Just bought a 2007 GS350 with 160K on it from a Honda dealer (trade in). The car is in great shape but i noticed some coolant leakage. Went back to the dealership they changed the radiator as they found that the existing one leaked. Unfortunately after driving one day less than 50km i notice that the reservoir is on the low mark when the engine is Cold and the antifreeze in the radiator is below full after just one day. Went back, dealer couldn't find a leak, can't see any leakage around the waterpump area either.....any idea what could be happening here? its not going into the engine because the smoke from the tail pipe is minimal, car is not overheating, heater in the cabin is working fine, i'm at a loss, i might try and return the car but i'm sure that will not be easy. Any help would be appreciated, i searched the forums for various coolant related issues but couldn't find anyone with my model car that experienced coolant loss after a radiator was changed. Thank you in advance

Brutus213

​​​​​​anyone???

Zmon

iTrader: (2)

Watch it after filling it up again. Someone might of just gotten lazy and may have forgotten to fill the radiator, leaving just the coolant that was already in the engine. Not unheard of. I'd be sure that if they did put anything in, they used Toyota Super Long Life (pink) coolant and didn't attempt to mix two different coolants.

ptplujo

iTrader: (1)

Check the radiator cap; if it's not tight, it wont allow for a vacuum from the radiator to pull the coolant back to the radiator and cause it to be pushed to the overflow which on most cars usually only happens when the car is at operating temps (i.e. when driving) and it drips onto the road. Thus, it doesn't look like any leaks are happening.

Lastly, ask for the dealer to do a pressure test on the cooling system also if you can't get it resolved or figured out. Do it soon or they may say you are out of warranty if you had any. A non external coolant leak is tricky and hard to diagnose without proper tools and technicians.

KevGS460ML

Back when my GS was new I noticed the fluid in the reservoir was on the low end. I would fill it up, but then it went back to low in a day or two. I left it alone, and it's been the same way every time. I flushed it twice, once at 100k mark, and then again at 150k. After I filled it up past low, it would again goes back to low. It has 154k miles now, and has never overheated once. So, I'd say what you're seeing is normal.

Mr4btTahoe

I'd venture to say there was air trapped in the system and the tech didn't "burp" it properly.

If you want to be certain there are no leaks, you can rent a cooling system pressure tester from most auto parts stores (you'll get your money back when you return it).. Pump it up and see if it holds pressure. If it bleeds off... you've got a leak and typically you'll see a drip at that point.

I'd take it back to the dealership though and have them top it off (since according to them it isn't leaking.. obviously they didn't fill it properly to begin with).. so you shouldn't be having to pay for coolant after paying them to fix it. See if it drops after a day or two and go from there.

Brutus213

update: so i filled the reservoir back up to full and i went ahead and changed the radiator cap to brand new one since the dealership didn't spend the extra $30bucks....the radiator has remained at full the last two times i have driving the car out, reservoir between full and low and looks like its staying there for now....so fingers crossed.....unfortunately it is possible like kevGS460ML said it might be a normal thing. I'll send an update after a few days, if everything stays the way it is now i think i might be out of the woods....i bought this car for their reliability unfortunate that i didn't find this coolant issue prior to purchasing it....here's to hoping this is the last major issue!! lol

ibidu1

iTrader: (1)

They more likely didnt properly burp the colling system, and most likely you had an air pocket in the cooling system. Once you drove the vehicle good, that allowed the air pocket to flow forward to the radiator

Brutus213

The coolant level should be between the full and low mark.....I changed the radiator cap maybe that will help.....do a pressure test on the system for peace of mind...I did that and there were no leaks....looks like the dealership didn't propeel burp the rad after changing it...so far on cool start the reservoir is between the full and low mark which is where it shud be....hope that helps