Overheating? What Temp should it be running at?

[e2stew]

So my Tercel that I have had for about two weeks has gone up a few times to about 3/4 up on the water temp gauge. and close to the white line below the red once.
Then it will go down ether on its own or the fan will kick on and it will go down.
Its not acting hot though.
I have searched the forum and started to go through the cooling system.
Flushed it, new radiator cap and napa premium thermostat.
I also tested the old thermostat and it seemed fine, opened at 185.

The car does smoke until it warms up, so head gasket is a possibility. But it goes away and I've looked for bubbles in the radiator, not sure i can see any or not.
The previous owner replaced the radiator from a wrecker and said that they had to top up the coolant once a month or so.
I haven't seen the coolant go down, until I started flushing/draining it.
Maybe water pump, but i ran it at high RPMs but still my normal driving speed and the temp gauge went to about 1/3.
The gauge is normal at half unless it starts to climb to 3/4ish.

My plan is to put in a mechanical temp gauge and put some numbers to the gauge. And proceed from there.
I did shoot the sender/thermostat area with a heat temp gun and it seemed like the fan kicked on at 195ish the the highest in that area was 208-210. Elsewhere like the valve cover I think was upwards of 230 but i was just shooting random parts.

So with a mechanical temp gauge what temps should i be seeing?
what if its still high on the new gauge, what order should i do things?
Water pump, then radiator, timing(i would have to have a shop do that), head gasket(shop)?

Thanks

[blade]

well on my 87 tercel my temp is at about 125F at runong temp. he is a auto and 4x4 so hope that helps

[e2stew]

@ Blade, thanks for the reply. Wow 125f ether my ether my engine is about to blow up or we are talking about different parts of the engine. Does your heater work? Isn't the thermostat set to open at 185f?
My heater is warm but not hot, maybe a sign of a blockage? Or a sign my gauge is off and it's not overheating?

Thanks

Still wondering what normal operating temps are and how hot is to hot?

[e2stew]

Side note question-
Which on of the two temp senders/switchs is the temp gauge and which is the overheat light.
This is for a '83 3a.
Standing at bumper looking at the engine, one is more on the passenger side next to thermostat and the other is closer to the drivers side.

And any tips on how/where to go through fire wall?
I haven't found and rubber plugs to go though.

[takza]

There is an area...I think around 7-8 o'clock relative to the brake booster where you can drill thru the firewall OK...just be sure you miss every thing....might need to remove the dist cap to drill. I drilled there and put in a grommet to run in some stuff. On a temp basis you can run stuff thru the crack in the fender and in the door if it's a wire.

My '83 usually never runs the fan unless it is summer and I'm chugging along offroad. You might have an issue with the fan switch? Try removing the sending unit wires and you will see which runs the gauge when it stops working? Could be your temp sending unit is bad? The best place to read the temps is at the thermostat towards the engine...what you are getting doesn't seem too much out of line to me.

[Petros]

sounds like it is running hot, not good for the head gasket. These head gaskets are too fragile even to run in the high end of the normal range. IF you are losing coolant and can find no leak it is almost certainly head gasket. I drove mine with a bad gasket for over a year by just adding water every tank fill. The water pump will almost always pump water, they typically have the bearing go bad and that takes out the seal, and it leaks. But it will still pump coolant. Very rare the impeller can fail, or break, but I have never seen it.

If your radiator is clean, and you have good T-stat, it should run cool. I will soon write up a procedure for replacing the head gasket and doing a modification to it to improve head cooling.

[e2stew]

Update-
I ran a temporary mechanical gauge.
It ranged from 185f up to 208-210f
185f equaled half on stock temp gauge
And 208-210f was at about 3/4 on gauge.
It was 185f while driving(I do have a very short commute.
In went up 208-210f while letting it sit at about 2000rpm.
That's the rpm that it runs when I start it up untill I tap the gas petle and It drops down.
When it reached 208-210f or some point maybe as the temp was climbing the fan would kick on and
Drop it down to 190-195f(ish).

Does sound normal or like it's overheating?
And
I have a trip up to Bellingham (2.5hour drive) next weekend
Will it make it? Or leave me stranded?

Thanks

[takza]

Not sure what the problem is...but I don't think my car has gotten above the middle of the gauge except a few times when I was adjusting my mechanical fan switch. Sounds like your fan switch is OK...but it shouldn't go up over the middle of the gauge before the thermo opens...did you install it right? Can't remember for sure if this car has one...but did you put the little opening in the thermo base plate to the top?

[danzo]

It sounds like your cooling system is operating properly and that you may just have a seeping head gasket like Petros said. Halfway (185F) on the gauge is normal, and the fan should kick on just above halfway to bring it back down. I would just keep an eye on the coolant level for now and drive it. 125F is too cool - you'll lose MPGs (right Takza?) and promote quicker cylinder wear. Not sure how blade got his to run that cool, assuming his temp reading is accurate.

Recently I had to do a semi emergency t-belt replacement, it's really not difficult on these cars. My 20K mile t-belt developed small tears prolly from debris, as I lost my upper t-belt cover (turns out there's a reason it's covered). In the process of replacement I ruined the fan switch at the bottom of the rad - the default is to run the fan all the time. I overrode this by joining the switch wires and just use the car's heater to keep it from getting too hot. In 30-60F weather this is good enough, those damn switches are $55! In the next few days I'll just mount a toggle switch on the dash to run the rad fan since it does cool it better.

[ARCHINSTL]

I can't really add anything to the advice mix, but as others have mentioned, the gasket is fragile. My B.S. (Beloved Sister) ruined my '83 back in '85 when she ignored the temperature needle (being accustomed to an idiot light in her Escort POS). This cost me over 1100 1985 dollars - and it still needed more work.
Goldie had a similar problem from the PO and had a reman head installed before I got her.
I will cheerfully admit I spend, literally, as much time looking at the temp gauge as I do the speedo.
Tom M.

[takza]

It sounds like your cooling system is operating properly and that you may just have a seeping head gasket like Petros said. Halfway (185F) on the gauge is normal, and the fan should kick on just above halfway to bring it back down. I would just keep an eye on the coolant level for now and drive it. 125F is too cool - you'll lose MPGs (right Takza?) and promote quicker cylinder wear. Not sure how blade got his to run that cool, assuming his temp reading is accurate.

Recently I had to do a semi emergency t-belt replacement, it's really not difficult on these cars. My 20K mile t-belt developed small tears prolly from debris, as I lost my upper t-belt cover (turns out there's a reason it's covered). In the process of replacement I ruined the fan switch at the bottom of the rad - the default is to run the fan all the time. I overrode this by joining the switch wires and just use the car's heater to keep it from getting too hot. In 30-60F weather this is good enough, those damn switches are $55! In the next few days I'll just mount a toggle switch on the dash to run the rad fan since it does cool it better.

I put in a mechanical switch for around $20...I'd be afraid to trust myself to remember to switch the fan on. Think I did a writeup on it. I also put in a fan indicator light that goes on when the fan runs.

So...IF it starts to overheat...and IF the fan runs...and IF the indicator light lights up...you know it's overheating.

If your coolant is at 125F...your engine will wear faster and you see poorer mpgs.

[blade]

so i am sorry to take over but dose that mean my car is running to cold?? how would i fix that???

[takza]

New thermostat?

[blade]

it has already been done.

[Petros]

Do not assume a new t-stat is good, you have to test it in a pan of water on the stove with a thermometer. Sometimes they are bad right out of the box. I only buy the best I can get (costs about $20 US) because the less costly ones just fail too early and I find they are not worth the trouble, you run risks of damaging the engine if it fails closed. Sometimes they open too far, sometimes not enough, the quality ones tend to stay in the correct range.