Sup guys,

I drove my 2000 T4R Limited (211k miles on the clock) to Detroit, MI. this past weekend to attend the Auto Show....5hrs to Michigan and 5hrs back to Chicago. She was a beast in the snow and freezing weather all the way there and back. Anyhow, car drove fine to and from Michigan without a hiccup. No overheating, no nothing. Got back home to Chicago Saturday night and all was fine. Sunday morning, I started the car and it started up just fine....drove it about a mile, then all of sudden the car started sputtering. Felt like a cylinder was dead or something. Idle looked fine on the tachometer, and still drove but sounded like a bad misfire. Got to my folks place, and opened the hood....and looked around, all looked fine. I squeezed the upper coolant hose, and there was no coolant in it. I popped the radiator cap off, and the radiator was bone dry. The coolant reservoir still had coolant in it....but no coolant in the radiator. The temp was not overheating though. I didn't see any white smoke, so I assume no blown head gasket. I didn't thoroughly look under the car for leaks, but from up top, I could not see any coolant leaks.

Anyone have any idea what could be happening? I love my truck very much and would hate to have it end this way. Any advice would be greatly appreciated.

Thanks.

You may still have antifreeze in it, just not showing up top. Top it off and see how much it takes to fill it and if its leaking anywhere.

Also check the transmission dipstick.

But would the coolant be that far gone? Usually there is still some coolant at the top of the engine no?...I mean in the upper hose?

I did replace the radiator two years ago when it took a dump on me (strawberry milkshake survivor). You think there is something with the trans? If so, what could be trans related?

The coolant isn't always at the top where the cap is, since you have coolant in the rez I don't think you ran it empty,you can have a tight rad cap that won't top off the rad when you shut it off, since you replaced the rad a few years ago did you use a toyota cap?..I've had bad luck with the cap the rad comes with{aftermarket}...since it's so cold out I'm sure you were running the heat and you would've been really cold if you were out of coolant. plus the temp gauge doesn't work if there is no coolant. How much did you dump in to top it off?? If it's less than a half gallon I'd go after the rad cap...
Checking the trans fluid will tell you if the trans cooler popped again.

What was the condition of your antifreeze (after the rad switch, did they put new fresh stuff in and if so did they mix it for max cold temperatures)

If your Sunday morning was as cold as ours here in southern Ontario (-25C) and your antifreeze wasn’t up to snuff you may just have popped a frost plug or hose connection.

I would refill and run it and check for leaks. If the antifreeze disappears again and there is no visible leak you know you have a different problem.

Don’t like the sounds of the engine miss though, likely the cold weather could have saved you from an overheat problem if you shut it down soon enough.

Disappearing antifreeze + no leaks + engine miss, you may be looking at a head gasket situation.

Good luck with it and remember, these old girls never really end, just depends how bad your 3rd gen addiction is, most things can be fixed.

Gary (Non techie driveway wrencher)

If the rad is low there might not be be any fluid in the top hose.
I wouldn't be concerned about that.

Coolant low and misfire.....not the greatest thing to hear.

FYI i had disappearing coolant and strange misfires for quite some time due to a headgasket but did not show white smoke until a little later.

What do the plugs look like?

All of that coolant went somewhere. Fill it back up and monitor it closely for leaks. I've had two different heater hoses leak, both were up against the firewall so they are hard to notice. They also both leaked directly onto the crossover pipe on the exhaust so I would never have any coolant on the ground (it would just burn off). You'll want to look closely in that area.

The fact that you had misfires concerns me. Hopefully you just have a leak somewhere and not a HG problem.

If you take the skid plate off and put a piece of cardboard under the engine it might help to figure out approximately where it's leaking.

If you lost enough coolant that the temp sensor wasnt in coolant anymore, it was then reading air temp and you were probably over heating but you didnt know it.

Might still be some water in there. If it was winter I'm sure he had the heat on. If it's low you'll hear the water slosh around behind the dash. I had a slow leak cause the same crap. Radiator was bone dry when I pulled the cap but it really took a while before the gauge would budge.

I've not seen a 3rd gen get the air bubble issue but the 2nd Gens would do that from time to time. It actually caused the opposite, the engine would super-heat the air bubble, causing steam to rise to the sensor and your temp gauge would spike into the red rather quickly, then the bubble would pass and then it'd go back down. Scary as heck, especially since those engines blew head gaskets if you looked at them funny.

Thanks everyone for the input. I am going to pull the motor soon, and do a full rebuild. It will be just in time for tax season, so I might just bite the bullet and get a Magnuson supercharger kit. I love this truck, and the money I have put into it with the lift, tires, suspension, brakes, etc... I don't think I can part with it.

Now, I just have to figure out where to start on removing the current motor....geez.

Did you verify it's head gasket? You'll feel really foolish if all it needs is plugs and a coolant top-up.