3 days ago I was driving my blazer and it started to feel like the trans was slipping. I looked down at my guages and I noticed my temp gauge was at like 240. I pulled over and let her cool down then checked my coolant. Rad was full of coolant. So after about a half hour I drove home with the heat on and it was fine. A few months ago I replaced the thermostat, and flushed out all the coolant and replaced it with green prestone 50/50. So yesterday I flushed the system again and replaced it with green prestone again. Drove it yesterday and it was fine in the morning.
Then later in the day, i was waiting to turn onto a busy road, and i saw a gap and hammered it, when I hammered it, it was super sluggish and laggy, at 30 mph it was at 5k rpms and wouldnt shift, it just popped, then i let off the throttle and it shifted. If I ease into the throttle it runs normal, but if you put your foot into it, its just really sluggish and wont shift unless you let off the throttle.
Also I noticed that my oil pressure used to always be at 40, then go up to 50-60. Now at idle its at like 15 and never goes above 40, even with it floored. I dont know where to start. Im also curious if these problems are all related? Yesterday it also became very difficult to start, and youd have to crank it over and over for it to finally start. Also, If I rev the engine when its in Park, it will stall. If anyone has any suggestions or any idea what any of this could be, I would really appreciate it. Its an 02 blazer LS 2wd 2 door with 46k miles. I thought buying a blazer with low miles would save me some headache, but this thing has been problem after problem.
After doing some research this is a list of possible problems i have come up with, TPS sensor, bad pressure control solenoid, sensor issue not giving the trans the right signal for when the trans should shift, Thats about all I could come up with. if anyone has any ideas or suggestions I would appreciate them.

good news. Check engine light just came on. Ill take it to autozone later and see what codes come up.

 

The code will definitely help narrow down one of the problems.

As far as the oil pressure goes, so long as it is higher than 8psi at a hot idle, it's A-Okay according to GM. I wouldn't really worry too much about it.

Have you replaced the cap? If not, I'd do that now. The Stant Safety Cap can be purchased for <$10 and is a dead nuts reliable cap. If the system pressure isn't maintained at 16psi, it can cause the coolant to boil sooner which can result in an overheating engine.

Also, have you paid any attention to the finned exterior of the radiator & a/c condenser? A dirty or otherwise restricted (bent fins, etc) condenser or radiator will reduce the cooling capacity of the system and cause the engine to run hotter.

 

Got 4 codes. p0131, p0137, p0151, cant remember the other one.. This would point to the oxygen sensor correct?
swartlkk, when I go to autozone to buy the o2 sensor(s) ill get a new radiator cap. Thanks for the response

 

Unless you can get AC Delco O2 sensors at your Autozone, I wouldn't bother getting them there. AC Delco, in my own testing, has shown to be much more active out of the box than any other brand and activity is a good indicator of how long the sensor will last.

And before you go out and buy new O2 sensors, diagnose the problem first:
P0131 - HO2S Circuit Low Voltage Bank 1 Sensor 1
P0137 - HO2S Circuit Low Voltage Bank 1 Sensor 2
P0151 - HO2S Circuit Low Voltage Bank 2 Sensor 1

With all those low voltage codes, I would suspect a ground or power problem to the O2 sensors. Look for similarities in the wiring & diagnostic tables for the two codes linked to above. There likely isn't a problem with the O2 sensors.

 

Can overheating cause your sensors to go bad? If not, ill go through all those codes and see if I can find anything. Thanks!

 

still cant figure out the problem. I unplugged all the sensors on the exhaust that I could find which was three, cleaned them, plugged them back in, and the problem is still there. Which sensor is sensor 1? Is it possible that just a wire is knicked? If I could find sensor number 1 i will trace all the wiring and see if the problem is something obvious

 

Follow the troubleshooting guide!
Like swartlkk said, troubleshoot the problem. guessing is expensive.

Overheating wont cause O2 sensors to fail. and actually, if your truck only hit 240, it didnt overheat.

I suspect there is a wiring issue with the sensor circuit.

 

I'll show my Dad all this and have him help me. Im only 16 and this is confusing haha

 

Put "oxygen+sensor+locations" into the search box and it should turn up a thread with a view showing the 98+ O2 sensor locations.

Sure its possible.

 

I would say youre doing pretty darn good for your age! Keep it up and good luck!