Overheating #3 Options

[Araykhel]

I'm back to the boards and at the mercy of you clever bunch once again. Right, so some background: Prior to last February I was overheating at the most random of times, coolant disappearing and the like. Replaced a thermostat, checked hoses, added coolant, and made sure never to drive any longer than emergency would have it when I got into the red. That evolved into a full blown leaking water pump and thus I fixed the issue on my own after learning how (thanks for that).

Now, fast forward three/four months since I changed the water pump and my engine overheats, I check under the hood and there is steam blowing out of the radiator cap. I did a flush (probably horribly) when I changed the pump and made sure the coolant levels were great but here I am with an empty reservoir/ plenty to add to the radiator.

When I drained the coolant last month there was no mixing that I could see, and just yesterday after a 40 minute drive I had good temperature but my radiator was spitting fluid from the "sealed" cap.


Help me you magnificent gear-heads.

[99gt3sge]

do a leak down test, and check the underneath the oil cap to see if theres any milky substance on it.

[nics]

You have an internal leak. It could be a blown HG to cracked cylinder head. Oil and coolant mixing is not always the case so you would not see a milky coffee like coolant.

The blown HG or crack in the cylinder head pushes the exhaust gases through your cooling system and this is why steam is comming out of the radiator cap. The radiator cap can only hold a certain amount of pressure and when it goes beyond this pressure, the coolant is pushed in the coolant reservoir. Since your cooling system is not a closed system anymore, this explains the loss of coolant in the form of steam.

[stephen_lee]

try replacing your cap first. if it doesnt seal all your water will boil away. the system NEEDS pressure to work properly.

get the car to op temp and grab the hoses... should feel good resistance to squeezing them.

[Araykhel]

You have an internal leak. It could be a blown HG to cracked cylinder head. Oil and coolant mixing is not always the case so you would not see a milky coffee like coolant.

The blown HG or crack in the cylinder head pushes the exhaust gases through your cooling system and this is why steam is comming out of the radiator cap. The radiator cap can only hold a certain amount of pressure and when it goes beyond this pressure, the coolant is pushed in the coolant reservoir. Since your cooling system is not a closed system anymore, this explains the loss of coolant in the form of steam.

I appreciate the responses, I will replace the radiator cap just to do something for the time being... However I can't help but agree with you nics. What can I do to confirm 100% that it is a HG?

[nics]

You have an internal leak. It could be a blown HG to cracked cylinder head. Oil and coolant mixing is not always the case so you would not see a milky coffee like coolant.

The blown HG or crack in the cylinder head pushes the exhaust gases through your cooling system and this is why steam is comming out of the radiator cap. The radiator cap can only hold a certain amount of pressure and when it goes beyond this pressure, the coolant is pushed in the coolant reservoir. Since your cooling system is not a closed system anymore, this explains the loss of coolant in the form of steam.

I appreciate the responses, I will replace the radiator cap just to do something for the time being... However I can't help but agree with you nics. What can I do to confirm 100% that it is a HG?

This was the test that was done on my 95 before.

http://www.youtube.com/watch?v=r1om5kFlT7E...feature=related

You can buy a radiator cap but it would wear out faster since there is excessive pressure in there.

If you confirmed that you have HC going into your cooling system, you have to take the head apart and physically inspect it.

[99gt3sge]

also make sure your fans kick on, my old 5s overheated once and it ended up being the fan switch that goes on the radiator. it wasnt completing the circuit for the fans to kick on.
to confirm do a leakdown test, and when you do it remove the rad cap, and if your head gasket is bad as u do the leak down test youll see water spitting out of the radiator. or it will begin to buble. honestly thats the best way to do it. it will cut to the chase and guessing on what it could be. imo

[Araykhel]

also make sure your fans kick on, my old 5s overheated once and it ended up being the fan switch that goes on the radiator. it wasnt completing the circuit for the fans to kick on.
to confirm do a leakdown test, and when you do it remove the rad cap, and if your head gasket is bad as u do the leak down test youll see water spitting out of the radiator. or it will begin to buble. honestly thats the best way to do it. it will cut to the chase and guessing on what it could be. imo

Fans work fine, though I see the importance in checking. That was one of the first things I checked last year when this all began. I managed to get a great estimate on replacing the HG since I am not capable to do it on my own something like $400 dollars for parts and labor and $150 dollars to have my heads machined.

[Smaay]

that is a pretty good price, and by the way, there is only one HEAD!

[Araykhel]

that is a pretty good price, and by the way, there is only one HEAD!

Curses! I didn't notice I said that.

[nics]

Buy the parts from toyota. Use the 98+ MLS gasket.