I have a SC300. Currently I am leaking coolant from the back of my motor once it heats up. It's a hissing sound and it's leaking coolant pretty steady. Any ideas of what it could be? or what lines run in the back of the motor?

My car overheated on the interstate today and I was shocked to see my resevoir and radiator had no fluid in either one.

Any suggestions?

 

Check your coolant lines that go into your throttle body. One goes across the valve covers, the other comes in from behind the motor. It's possible one could be loose.

 

Alright, will do. I am taking it to a shop today that specializes in Lexus/Toyota's, so hopefully they can put it on a rack and see where the leak is coming from.

One of my guy friends says he thinks I have a blown HG but I don't think that is the case. I have no signs of one except for this leak in the back.

 

Have you had the TB off for any reason lately (changing plugs, or anything)? I always have a tough time getting the bottom coolant line back on snug since it's underneath everything.

 

No, not recently. Come to think of it, Ive never removed it. Hopefully this is a simple fix. I am driving the car without a fan shroud though. I cracked it so I removed it. Do they make a significant difference in cooling?

 

Ya know, I immediately thought head gasket when you said back of motor, but there are lots of things that could leak back there... heater hoses, throttle body hoses, etc...

 

Well, anyone else have any ideas of what it could be? And does the radiator shroud really have that much of an effect on keeping the motor cool?

 

yes, the radiator shroud is very important... without it, the fan will pull nowhere near as much air through the radiator... this same goes for every type of fan - without something to direct air movement, a fan just doesn't work well...