Overheating and Loss of Power

2000 Tacoma PreRunner, 2.7L

About three months ago, the truck ran hot on a trip to from Atlanta to Alabama. I added some 50/50 coolant and it was fine until two days ago. It overheated in a bad way on my way home from work, which is about 15 miles and a fair amount of traffic. I stopped to let it cool down and I added more coolant to the reservoir (not the radiator) and tried to make it home. It died once and barely made it the final mile or so. Very little power and lots of valve/cylinder noise. Once home I checked the reservoir and it seemed like the coolant I added didn't make its way into the system.

I took it around the block the yesterday and the issues remain. Idle is fine, but once I hit the gas there is no torque. It will get up to speed, although I didn't go past 45mph or so. There is a CEL that I've yet to read. There seems to be a slow drip from the radiator, so perhaps it's cracked. It also feels like there's some sort of exhaust leak but I'd need help to confirm that. Any ideas would be greatly appreciated!

 

Definitely get that code pulled, take it down to AutoZone or O'reillys and they'll read it for free. Post it up here and that should definitely help narrow it down.

How does your coolant look? It's not milky or brown is it? No particles floating in it or at the bottom of the reservoir?

 

Code is P0115.

 

Check out this webpage:

http://www.obd-codes.com/p0115

Sounds like your Engine/Coolant Temperature sensor needs to be replaced.

 

I wouldn't go replacing any sensors just yet, the sensor sure cant work correctly if there is no water filling up the system so first refill coolant to proper levels after replacing that radiator and then see if the cel code returns, I bet it wont.
our rads are famous for leaking around the top shell at the seams

 

You mean like this?

 

yep, often all you see is a wet radiator because the seam opens up and the fan sucks it into the fins so you don't often see water actually peeing out anywhere

 

Have you checked the engine oil yet?

 

the only reason the "water" doesn't evaporate inside the system is because its pressurized. if there is a leak it will instantly evaporate so you wont really see anything like keakar said. get yourself a shiny new radiator. also checking oil doesn't hurt, but I think you will be happy with what you find.
the fact there is coolant left on the grill shows how bad it must be

 

Evaporated coolant will leave a powdery substance where it evaporates from.

 

Update: Replaced the radiator and thermostat. Still running hot but there is no longer a loss of power. Something else strange; the "low oil" light comes on once I start driving but there is plenty of oil. Haven't done a compression test yet. There was no oil in the coolant that I drained from the old radiator.

 

The coolant will likely contaminate the oil. It gets hot enough to turn to steam but being kept under pressure keeps it a liquid and not a gas.

 

It's not a "low oil" light. It's a "low oil pressure" light. That could be a problem with the oil pump or worn engine parts (bearings) if you're not low on oil. Could be a bad oil pressure switch also, or the wire is disconnected or loose on the switch. I believe disconnecting the wire will cause the oil light to come on.

Also, did you put a new radiator cap on?