Coolant Recovery Tank

[Nate]

I have a 1994 LS400. I have 75000 miles on the car. Recently the coolant in the plastic recovery tank disappears within two days. I check for leaks and could not find any. There are no drips on my garage floor either. A friend told me he thinks the radiator might not be working properly so the coolant is leaking from the overflow hose when it is being driven. Has anyone had this problem before? How much does it cost for a new radiator? Thanks!

[wwest]

Most likely your coolant is exiting the vehicle via the exhaust pipe. Watch for white smoke, steam, out the back of the car when you floor it.

Blown head gasket if so.

Oops, sorry I got that a bit wrong on first pass. You will see the steam just after getting OFF the gas. With the throttle closed and the engine still at high RPM the "excessive" vacuum will pull coolant into the cylinders.

[obergc]

I am losing a little bit of coolant out of the reservoir but I am finding that it is leaking from the reservoir somehow. It's not leaking much and it only takes about a cup of water to put the low coolant light out and it comes up to the right level when it's warm. So far I haven't been able to find out where the leak is but it's apparently near the top of the reservoir. I suspect that the cap may not be working properly and the reservoir is not being pressurized as it should. Gonna check it out further soon.

Curt

[michaelsn]

My '91 Acura Integra was doing the same after 8 years. It turned out to be a hairline crack on the plastic top section of the radiator. I didn't catch it until I topped it off, drove for about 15 minutes and lifted the hood. Steam was coming out of the crack.

I bought a kit from Acura (seems like a common problem) which consisted of a new plastic top section only. I took some work taking the radiator out and taking the top off and replacing that section but I didn't have to buy a new radiator.

Lexus is definitely built better but it's probably worth checking.

[Zdeno]

I had same problem and time to time I heard some niose like a air coming off the engine area. Mechanic found some small crack on the cooling tank. I let the exchange the tank and I don´t hear the air anymore and water light on dashboard doens´t come on. So I think that it was problem with the TANK. But when my 1991 LS 400 is cold the water is 1 inch under minimum and when the car getting warm the water coming up to MAX. Now I have a air in cooling system.