Please confirm that this is a bad headgasket.

[Slater]

Started when I was doing some spirited driving on a local highway, noticed it was accelerating slowly, and the temp guage shot up from normal temperature to over the biggest line on H in a total of about 2 minutes. Pulled over and I saw smoke come out of the coolant reservoir area, and coolant pouring out of overflow bottle. Also heard a constant gurgling sound coming from the engine bay. It overheats often when I drive it now, even if shifting normaly. I am losing coolant, and there are very big chunks of white smoke coming out of the tailpipe when the car is first started after a break. It was taken to emmisions testing and got almost double the allowed NOx reading (12xx vs. 22xx) , and passed every other test.

The car has 186,000 miles, and from what I was told by the previous owner (older guy), it is original everything. Will burp out the cooling system and confirm as soon as I get time.

Thanks for helping a n00b.

[Isphius]

It could be a thermostat or something, But definatley sounds like a BHG. Its not a hard job to replace it. You can do it in about 3-5 days if you are working alone. Even if it isnt bad, Its a good idea to replace it. And definatley use brand new toyota or arp bolts. Or studs, If you feel like shelling out the money, cause they make it a lot easier to put back together. And just use masking tape and a marker to mark where all the coolant lines, Connectors, and hoses go. Goodluck withj you supra!

[suprasforlife]

Check your oil for coolant. If there is coolant, it is a BHG. If you can't see any, smell the oil that is on the dip stick and see if you smell coolant. Any coolant in oil means BHG.

[Slater]

I have a spare JDM motor here so I'll swap out the T stat when I get time. For now I have 5 days to pass emmisions. Is the BHG related to the high NOx reading? Is there anything I can do right now to pass emmisions besides try to replace the HG and see if that fixes it?

You probably see these threads pop up every once in a while, thanks for having patience with a n00b.

[Isphius]

For your high nox, replace your cat and see if your egr is working. I am not 100% sure on this, but my 7mge had a minor hg leak and my nox were 3x higher than passing. I never fixed it and went back to inspection thou so i dont know if that was a cause. And that was with a working egr valve. and old cat. To test the egr, Way at the back of the motor on the driver side there is a round thing bolted to your intake, And the vaccum line that goes to the back of it is your egr valve. Plug that vaccum line into a direct vaccum, Like the one at the very back on the intake. If your motor coughs or sputters, It is working. It may even stall. And im not sure how to test the modulator (round part), But those are very easy to replace if bad. As long as your valve works and coughs the engine out your ok.