I bought this GX a few months ago and when I bought it I noticed the coolant level was down below the L line in the reservoir. Last week I finally got a hold of some Toyota ling life coolant and filled it to the F line and when I checked it one day later it was back down below the L line! What's weird is I don't see any leaks and I would think if it was a head gasket issue it would keep consuming coolant until the reservoir was completely empty but there is always a an inch or so in the bottom of the reservoir Any ideas? This truck has perfect service records and 144,000 miles. II hope I didn't buy a lemon any help would be appreciated.

 

was the water pump replaced at the timing belt service? its possible there is a leak and its burning off a hot surface, radiators are a frequent replacement item on these trucks.

 

I'm not sure if it was or not. I believe so but I'll have to check.

 

It could be as simple as rad. cap, To be sure just do a pressure test for the cooling system. Worst is head gasket issue which we don't wish.
How is the coolant temp. reading on the dash?

 

Coolant temps have been fine. Is the pressure test something I can perform?

 

Went and picked up the GX from my wife to take it to autozone to rent a radiator pressure tester, before I left her work I filled up the reservoir to the F level. When I got to autozone (2 miles) I looked under the truck and this is what I found. So I'm thinking I need a new radiator.

 

You need test kit with pump. With rad cap adapters one can test all kinds of vehicles. I happen to have one in my tool
chest. Another test is; if your cabin heater works fine that is good indication water pump is working good. Sounds
like cap is not keeping the pressure losing collant due to old age if it is original one. Hot engine can boil of fcoolant
without trace some times. Pressure tester also can test cap.

 

I went ahead and bought a cap. Hopefully that's it but won't know till I test the radiator.

 

I pulled the shroud to get to get a closer look. I don't think it's the cap, looks to be coming from the top area where a crimp came loose. It's leaking so high up on the radiator I guess I didn't loose too much coolant which explains why it hasn't overheated?

 

There's a small hole where those crystals are built up, common issue. Time to replace the radiator.

 

Yep that's what I figured.

 

So I'm having a hard time sourcing a Koyorad. What are some other reputable replacement brands? I've found a Denso for a reasonable price but don't know of their quality.

 

Get the Denso.

 

Denso is good so is koyo, do some research, i ordered mine online got a hell of a deal. oem radiators are known to leak there

 

I ordered the desno, upper and lower hose, thermostat and gasket. Plus 3 gallons of xerex asian which I know is not recommended by Lexus but I've read it's a good cheaper alternative.