Thermostat is 195

Hello So I'm new to this community so be patient please. Truck is 2000 sr5 trd 3.4 140000 miles.

My truck overheated and the coolant was empty both in the reservoir in about 2" below he radiator cap. I live 40 miles from the Toyota specific mechanic so I have the local mechanic look at it. Pressure tested it in the radiator was leaking so he replaced that and added dex cool to my toyo red! (found this out later too)

I drove it for about 60 miles steep grade was watching radiator fluid and it looked good. I got home from another trip about the same distance checked the radiator resevoir and it was empty again. He put in a thermostat from autozone (which he later told me was rated at195). when I drove it the lower hose seemed much cooler than i thought it should be (i didnt know that the tstat was a 195) took it in an He said it was prob the waterpump. So I reluctantly consented (I Also had the timing belt replaced of course) I got smart and bought an OBD adapter to Bluetooth and the torque app.

So on a 65ﾟday I drove it 20 miles with 2500' of elevation gain. Temps ranged from 190 with the thermostat gauge directly at center where it stayed (it had always been about a 3rd up before) to 200f. The fluid stayed consistant but was not clear (turns out he hadnt flushed the system just added dex cool to my toyo red) Oil is not milky but the synthetix high milage I put in it was low a half quart at 5000 miles which isnt that unusual but was much cleaner than im used to at this mileage. He didnt have a gas tester for the rad fluid.Check engine light has NEVER come on.

My questions are...
1. Should i be concerned with a 195 degree thermostat going into New Mexico 100 degree summers.

2. Could I have a small head gasket leak to just one cylinder. no white smoke. rad fluid pressure test at 10 min was consistent. truck doesn't miss (no check engine lights) lots of clear fluid on first start then a little after truck sits there. (doesn't smell like rad fluid) from tail pipe.pipe is now rusty as opposed to slightly black dust.

3. Would I do best just to flush the whole system and put in a toyo tstat ( what does jiggle at 6 or 12 mean n which runs cooler) or a better quality after market rated at 170 or 180?

 

I would not be concerned about the 195 degree thermostat... the thermostat regulates the coolant temperature in the block. It is the radiators job to disipate the heat from the coolant to the air. You have a new radiator so I wouldnt worry. If the coolant temps rise while forward speeds are relativly low, under 25 mph, then you will need to put a fan clutch on her too. Do a search on a "green fan clucth" for more info... Forward movment above 25 mph'ish should provide enough air flow through the radiator for cooling.

the water from the exhaust on cold start is normal, the exhaust system hasnt warmed up to vaporize the water in the air on cold start.

you mentioned the Check engine light has never come on... does it illuminate during the bulb check portion of turning the ignition key?

you also mentioned that the pressure in the cooling system remained constant when tested, was the pressure cap tested at the same time?

the jiggle valve... when you look at the thermostat around the outer rim there is a hole drilled and a small metal "dingle ball" that is inserted. On the V6 it should be installed at the 6 oclock position, not straight up 12 oclock. It runs cooler installed at the 6 oclock position.

Not trying to be an ass here but I learned something a few weeks ago when talking with a neighbor kid, maybe he was 8 years old. He lives in the digital era and has NEVER seen a clock with hands on it before so I had to explain 12 oclock, 6 oclock etc. It is just the world we live in.

 

Thank you Glamisman.
Sorry I should have said the check engine light hasn't come on during this situation. It does light up pre ignition. It has come on before with other issues and I rectified those problems myself (maf , 02 fuel ratio sensor etc)
By pressure cap do you mean the radiator cap? My mechanic Installed a new one with the radiator. I believe he pressure tested in the place where the rad cap goes on.
i will have to ask my mechanic when I can if thats what you mean.
Ive had the same issue with reguard to digital clocks with my freinds kids. I'm a critical care nurse and have had to teach new nurses how to tell time on the clocks in the ICU. Don't worry I am a strict preceptor!!!! lol

 

Yes absolutely. The position is 6 o’clock and will lower temps 5 degrees. I didn’t believe this until I tried both positions.

 

As stated, 6 position for the 3.4

 

Flush out that Dex-Cool. If I'm reading this correctly, I think you're ok.

You are NOT still losing coolant....right?

 

very small leak at heater control valve.Watching like a haw will replace at flush
Is dex cool bad?

 

Don't mix Toyota antifreeze with anything else. It's a bit of it's own species.

 

safe to drive for a little while?

 

yea, a bit. Don't procrastinate 'til it possibly turns into red goo.