mccalj

I have a 93 GS 300 with 154K miles on it. Bought it at 149K. Since then, it has overheated on me twice. It has a new radiator. I can smell coolant inside the car at times, but outside as well. No leaks are to be found. The resevoir cap seems to leak, but nothing major. There are no signs of a leak on the passenger floor board as far as the heater coil. The car is in great shape for its year and I have all intentions of keeping it, but need to find out where the coolant is going. Any suggestions would be appreciated.

mak89

iTrader: (6)

Guess a radiator leak down test wouldn't hurt

SadKamper

Check your Engine Oil bro, that's probably the causing to over it, If you need an oil change, or have in the wrong oil because the inside parts of the engine creating soo much friction causing it to heat up high.

LexISGS300

iTrader: (2)

Head gasket?

BCP43002

Any smoke out the exhaust and if so what color?

mccalj

It shouldn't be the radiator since when I bought it they said it was new.

mccalj

I just changed the oil. I also made sure it was the correct type. However, I did change the radiator cap. The resevoir was bubbling before I did when hot. It doesn't do it anymore but still leaks out the top. The cap to the resevoir isn't supposed to have play in it does it. It will snap on, but it's not tight. Does the cap have a rubber groment or seal underneath?

mccalj

Im new to this, so give me a chance to get familiar with everything. I have no smoke coming out of the exhaust.

mccalj

I'm not real familiar with head gaskets, but from what all was saying, I don't think, or I hope, it's not that. The resevoir cap is still leaking and I replaced the radiator cap.

mccalj

When I bought the car, I was told a new radiator was put in by Lexus last year.

BCP43002

Does the top radiator hose get hot? If not your thermostat is stuck closed causing the overheating.

freshmoney

mines overheated this morning(same issues bubbling in reservoir )..... i just installed my rad 4 months ago..... new cap, and hoses. i i think my thermostat is stuck closed gonna change it later...... keep you up dated

link13

Head gasket failure is common on these cars. People used to say it never happened, but that was before the cars were 15+ years old. Does your overflow reservoir go bone dry, but you have coolant in the rest of the system?

There's a tough place to see at the back of the head and block, but that's a common place for a coolant leak. There's a hose back there for the heating system and I had that replaced hoping it was the source of the leak. It had been leaking, but I also had a leak at the back of the head/block from the head gasket. The gaskets corrode. Sometimes, the block will corrode too. Mine didn't. I got lucky.

My head gasket was done for a few months, but the car never overheated, so I kept driving it. One morning, it just let go completely and there was a strong coolant smell in the exhaust. The point of all this is people will tell you to check for coolant in the oil and that's correct, but you still may have a bad head gasket even if you don't see coolant in the oil yet. My personal opinion is your head gasket is the problem.

freshmoney

i just replaced my thermostat with one from advanced auto part. i haven't tested the old one yet to see if it was bad but it looked pretty old. I refilled coolant levels. and the car is not over heating. after first it did overheat but i had some air in the system. i ran the car with heater on high and cap off for about 5 mins. after that it returned to a little over half. i think i still have air in my system becuase it used to run just under half normally....

link13

Yeah, the tip we got was to jack the front of the car up to help bleed the air out of the cooling system. Do everything you just did, but with the front of the car on jackstands.