NEED HELP OVERHEATING ISSUE 1997 3.4 base model tacoma

Hey taco fam i have a 1997 tacoma base model with the 3.4 in it i bought it about 7 months ago when i took this tacoma to get smogged the shop told me she wasn’t running at operating temp and that either the thermostat was faulty or something else to do with my water system was faulty after looking around i notice the truck didn’t have a thermostat to begin with so i thought easy fix. i threw a thermostat in there and started the truck went to drive it to warm up the cats for a smog and overheated within two blocks of my house so i thought faulty thermostat tried 2 different thermostats neither worked (all purchased from oreileys). from there I replaced the water pump the radiator both hoses and the radiator cap the truck still overheated with athermostat in it. after explaining all this to a shop they said for sure i have a blown head gasket. when pressure checking the block the test came back negative for a blown head gasket after explaining this to the shop they said they don’t know and would need to tear things apart to seewhat’s going on does anyone know what the problem could be?????

 

Has anyone monitored actual temps on the vehicle?

The gauge is useless; what does OBDII monitoring say?

 

the truck runs at 150-160 degrees should be at 190 so it runs cold and at higher rpm’s trying to warm up and it never gets over 165-170 regardless of how hard i push it this is all with no thermostat in is so it makes sense the block is just getting flooded with water with no restrictions. i don’t know why it won’t accept a thermostat or run properly with one in i have also replaced the temp switch.

 

thank you for getting back to me brother

 

I asked if you monitored via OBDII because the gauge is a dummy gauge.

When you say you replaced the 'temp switch' was that the one in the front of the engine or rear?

Any engine codes?

 

the one closer to the cab ,from the front bumper it would be the farthest away so i guess the back ,and yes i have a minor exhaust leak i think it’s a P002 code or something similar. and i haven’t watched the temp while driving through a reader but after a drive when i check it with a reader it states around 160-70 depending on how far and fast i was going.

 

Couple of things - the sender in the back of the engine (closest to the cab) is the one that communicates with the gauge, it's useless.

The one in the front is the one that controls closed/open loop and operation of your vehicle, and also the one that allows data monitoring through your OBDII.

 

so do you suggest changing the one in the front i examined it and if i’m not mistaken it’s right behind the timing belt plastic cover closer to the left side.

 

I'm not the type to suggest replacing parts without proper diagnosis, cause that could get expensive very quickly.

Just posting really to inform you of the workings of your truck.

Get that exhaust leak taken care of.

 

do you believe either the front temp switch or the exhaust leak could have to do with the overheating problem with the thermostat in ? regardless obviously ,yeah i will have to get around to the vacuum leak i’m just rocking 2022 tags and this is my main concern at the moment for this truck. thanks again

 

My post above already explains what the switch does in relation to operating temps.

 

alrighty i’ll give that a try thanks again man