Truck is overheating and has total loss of power... any idea?

I have a 1996 Tacoma 2.7l 3rz 4x4 249xxx miles. Last month the truck's idle started to die while driving then temp slowly crept up. I got the truck home but when I restarted it there was a HUGE power loss. Feels like the engine is being restricted or something. It struggles right off the bat under any load. Took it on the freeway and struggled to go speed limit at 50mph in 3rd gear where prior I could cruise at 70mph in 5th.

This power loss has something to due with the overheating also. The truck starts right up and can idle for an hour but I can only drive around the block a few times before it starts to overheat and idle starts to drop to where the truck will die out if I let off the gas.

Truck was throwing some codes so I have replaced a bunch of parts already clearing all codes.

There is a brand new Toyota dist., wires, plugs, IACV, crank sensor, fuel filter, air filter. I also took off the cat and put on a straight pipe hoping that was the problem but it did absolutely nothing.

Timing was checked, no engine check lights, no milky oil or white smoke from the exhaust. Kinda running outta ideas here on what is the issue.

Any help would be much appreciated. Thanks.

 

You say it overheated and you made it home. How overheated? Did it stall because of the overheating at all? You may have warped your head or just totaled the engine, Just my thoughts.

 

Went just below the red. Not over and just so happened I was near home. While it was hot I could not let off the gas or the truck would die. I guess that could be considered stalling.

Is there a way to check if my head or engine is warped?

 

Easiest way to check the condition of an engine is to do a compression test. Pull the spark plugs and see what they look like. That'll tell you a lot about what's going on. Had a volvo 240 with the same exact symptoms, the gauge read high, and it ran like complete shit. Turned out to be the ECT sensor making the car run pig rich / read high on the temp gauge.

 

so your truck is overheating and you have done nearly everything to try and fix it but have yet to try to fix any potential cooling issues? ill be surprised if your truck survives this without major work......

firstly, check your compression like Rusty said. make sure you overheating hasn't destroyed the cylinders or screwed anything up. do the compression tests slowly, they should all be around 160-190 psi. if you have 110-145 psi, you have minor issues, anything under and you have major issues. pressurize any cylinder under 140 and listen for air leaks in either the intake (from the throttle body), the removed oil filler cap, or the exhaust. that will tell you if theres a bad intake valve, bad rings/cylinders, or bad exhaust valves. if 2 neighboring cylinders are low, most likely just a bad head gasket.

secondly if it hasn't been done for a while, change your water pump, thermostat, coolant, upper and lower hoses, fan clutch while your at it, and get a good cleaning/flush on your radiator. perhaps your coolant is just so old it's lost it's cooling effectiveness and just needs new coolant.

 

When is the last time you flushed your coolant?

 

Sounds like head gasket is blown

 

Pulled the original spark plugs and they looked fine. Replaced them anyway. When you had the ECT problem was your car throwing a code? Did it run super bogged down? I didn't even make it to 4th gear on the freeway because the truck struggles soooo much now.

Thanks I'll go see if I can get my hands on a compression tester, learn how to use it and run these tests. Fingers crossed that I'm atleast in the 110-145 psi range.


Thermostat is gutted so the truck normally ran extra cool.

I've had trucks where I had to change out the radiator and thermostat due to overheating and plugging but generally it had no effect on the power or how the truck ran.

That is why I'm kinda thinking that what ever is causing this drastic power loss is also responsible for the overheating.

 

When my car did it, it would only run on like 2 cylinders. I couldn't get it out of second. But old volvos rely heavily on that ECT and o2 sensors. I don't think our pickups rely that heavily on them. They're important, but I don't think they'd cause problems that severe.

 

Any updates on this, OP?