1993 Es300 Coolant In Expansion Tank Is Boiling

[canbrass]

I have a 1993 ES300 that has about 240k miles on it and the coolant in the expansion tank started boiling. I was told it was a blown head gasket, but here are my reasons why I don't think it is:

1) The oil looks just like regular clean motor oil. There is not white or creamy color to it.

2) There is no oil, sludge or grey film in the coolant tank. It looks like green Penzoil coolant.

3) The tank only boils when the engine gets warmed up. I think that if it was a blown head gasket, it would blow exhaust out of the tank when the engine was first started.

4) There is no smoke that comes out of the tail pipe. It does drip some water, but I think that's pretty normal for any car.

5) When you rev up the engine, there is no noise or vibration that comes from the engine.

I think that it's a stuck thermostat, but that's only a guess. I am open to any advise or suggestions anyone has. Thanks!

[2onthreeputt]

What does you temp gauge read?

I'm no expert like some of the other guys on this forum...but I just did the head gasket (both sides) on my 92 (143K) and i did see a bit of reddening of the coolant, but my oil looked fine the whole time. My expansion tank did have some reddish crap in it as well. I kinda thought it was simply neglected as the car wasn't maintained very well by the previous owner. There was no skipping or engine noise at all....thing ran like a top..very smooth.

You might be able to test it by taking a coolant pressure tester and seeing if the pressure in the cooling system immedately starts to rise...As a fleet mechanic, I also seem to remember we had these little strips that would test for combustion reminiants in the coolant...

Anyway, with that kind of miles and the cast iron block/aluminum head deal on the 92/93's..I would think head gasket might be in order...I did it myself along with milling the heads, plugs, plug wires, full toyota gasket kit, O2 sensors, etc for about $1100 total..I also did both sides...

Good luck man..