Coolant temperature

How many miles do you have? As it was mentioned earlier its rather unlikely its the water pump since they generally either work or not at all. Not to throw parts at it but if you're at any reasonable number of years/miles it may just be time for a cooling system overhaul. Radiator, hoses, water pump and thermostat, maybe even fan clutch. None of them are overly expensive and somewhat easier to change all at once. Not sure what you used for previous parts but should stick to OEM / AISIN for thermostat, water pump, fan clutch and OEM / DENSO for radiator. Maybe you have a defective thermostat that is not opening all the way, to me it sounds like that or the radiator is clogged.

 

the thing is that recently i replaced my engine so it has around 50-60k miles , the earliest engine had a new water pump but I am not sure if the guy had put my water pump or no, I forgot to mention but i recently replaced the clutch fan and the radiator cap as well

 

so what is normal driving? in my world, highway is included in normal.

i think it sounds like a partially blocked radiator.

 

Normal driving meaning inside the city low speeds, I guess I will start with replacing the radiator with the hoses cus i flushed the radiator and not much difference

 

i have bought a thermostat that was defective. have you ever tested one in hot water with a thermometer? but in my brain, i think if it was the t-stat, it would get hot in any driving condition.

 

how do you know your actual temperatures? you have a real gauge? i cant remember my gauge in my 2006. i dont recall it having hatched numbers.

 

The radiator can also be reconditioned but these days it almost doesn't pay as cheap as radiators are/were recently

 

i have a scan gauge

 

I thought I’ll check how much to get a new one if it’s way expensive maybe I’ll recondition the one that i have and test it but honestly I feel like much better to get a new one

 

yea I don’t think its the thermostat cus it only gets hot on the highways ( around 59F increases)

 

The shop that installed your used engine is very unlikely to have swapped your water pump onto it.

You still haven't mentioned the thermostat brand, or the brand for any other parts like fan clutch and radiator cap which if it isn't from Toyota or the OEM manufacturer for that part (AISIN/DENSO etc.) I wouldn't rule that possibility out. A thermostat isn't only open or closed, it should start to open at XX rated temp, and continue to open more until its fully open at a certain max temp. It's possible yours is defective and opening a bit but not enough coolant flow to keep up with higher loads. This was also all pretty much mentioned in the first responses.

Not to come off wrong but it's your truck and none of us are physically there, so we can't always just give a definitive its this replace it and you'll be all set. Details and a timeline are important for diagnosis. I might have missed it but you didn't explain much details about how long its been happening, if it was sudden vs over time, if it happened after fan clutch and thermostat, or if that was a first effort to fix the problem. How recent is "recent", give number of miles on truck, and since engine replaced how many miles did that engine have and how long ago was it swapped. Have you been losing coolant, are there any signs of head gasket leaks, etc. etc. Diagnosis is much harder without having the whole picture.

 

Thermostat is oem
Radiator cap is oem
Clutch fan is AISIN

to be more accurate i used to have the same temperature issue with the older engine as well but it was happening on more higher speed around 90mph and more but now no even on lower speed on the highway around 70 mph it will start increasing

the older engine had 183k miles
The new engine i bought and it has around 60k miles and I added 3k miles on it , the temperature issue was there immediately after I took the car from the workshop and test it
The is zero loss in coolant I don’t think it’s leaking somewhere

 

You said you felt the rad hoses with the truck on and they had pressure, so I am disinclined to think water pump.

It's sounding more and more like a clogged radiator. If the problem had started before the new engine, the swap could very well have shaken loose more junk and made the clog worse. If you have or can jimmy up some fittings, you can try to flow test the existing radiator with a garden hose, but it would be eyeball at best unless you have pressure meters for either end.

I would hot water test the thermostat just to be sure, and if that's good, if it's my truck, I'm sucking it up and putting in a new OEM or CSF rad.

 

I would probably just replace the thermostat first with an OEM one to ensure it's working properly. If the problem persists, swap the radiator. When my radiator needs replacing, I'll probably spend a little more for an "all metal" radiator from a manufacturer like Mishimoto.

 

Very first post he says he has replaced it already. A few posts above he says its OEM, kinda doubt thats the issue at this point.?

 

Forget the thermostat, it's extremely unlikely that if this was a thermostat issue that it would have the SAME SYMPTOMs after replacing it with a new OEM thermostat or even a new NON OEM one for that matter.

 

Then my recommended first step is complete. Questions?

 

Thank u guys for your feedbacks, now I will replace the radiator and hopefully solve this issue.. I will update u once I replace it and test it on the highway couple times

 

Yeah having all that information laid out makes it a lot clearer. Based on the fact that it was present with both engines strongly suggests something on the chassis side (radiator, clogged hoses or heater core maybe, etc.) Like said above, OEM/DENSO rad is a great next choice to hopefully resolve it for pretty short money, at 183k (assuming original) it's not a bad thing to do anyways. I don't have any experience with aluminum aftermarket rads at least on tacomas.

 

When the engine is at operating temp or maybe starting to overheat, check the temp of the upper and lower rad hose. If the top is screaming hot and bottom ambient then your rad is plugged. The lower of course should be much cooler but still fairly warm.