4AGE: 1989 mr2 thermostat........

[newelly]

4age,will it overheat without using a thermostat?

[mr3]

Shouldnt, when mine went out it was stuck open and it wouldnt heat up.

[newelly]

Originally Posted by newelly

4age,will it overheat without using a thermostat?

threw a belt......must be the reason for over heating and dead battery,,, thanks

[mr3]

Um, now that you say that, you most deffinatly will overheat! My belt snapped on me in 30 degree weather and I overheated in a few seconds. It's not a smart thing to do to drive witout the alternator and water pump running. The pump keeps the coolent cycling through the system and it does stay pretty cool. Without that, YOU WILL OVERHEAT.

[toyotaspeed90]

the alt and WP belt are the same belt on the 4age's......

you shouldn't run w/o a thermostat as the temp will be too low and you'll get poor performance and mileage.

[newelly]

Originally Posted by toyotaspeed90

the alt and WP belt are the same belt on the 4age's......

you shouldn't run w/o a thermostat as the temp will be too low and you'll get poor performance and mileage.

i was having the o.h. problem so thats why i took it out.i have always ran with one. i have a nose cone on the car that maybe was not allowing enough air flow.there is no front air dam. i took off the bumper cover and drilled holes 4 air to pass through over and under the bumper. raced last night and won a heat race of 10 laps with no overheating. now before the car never overheated with the bumper cover and nose cone on. how much performance you think u would lose running w/o thermostat?? car never leaves 2nd gear,starts smackin the rev limiter right at the end of the straight.perfect for 3/8 mile track

[mr2tim]

Like Toyotaspeed indicated if your heat gauge isn't straight up the ECU isn't reading the correct sensor inputs for optimum horsepower.

You will NEVER generate enough heat in the pits at idle (or other) fast enough to just go right out on the track without a thermo. (BTDT)

BTW did you know the E-51 "Supercharged" self-oiling transmission which fits your 4a series engine is a factory close-ratio unit, like
how about 3rd gear at the end of the straight?

Just a "passing" thought.

Supercharzed Toyz Raczing
S.E. Division, SCCA Racing
South Florida Sports Car Club

[toyotaspeed90]

sounds like it's a racecar.....

I wouldn't recommend doing this for a daily driver.... but what you may want to think about doing is....

run without a thermostat.... this will only bring the temp up to probably around 150-160 (guessing here)..... however, install a potentiometer onto the ecu's coolant temp sensor.... performance will be affected when the coolant sensor reads a low coolant temp and it will add extra fuel.... in an n/a engine, this isn't what you want. You could probably even lean it out a bit and gain even more performance....

[toyotaspeed90]

Originally Posted by mr2tim

Like Toyotaspeed indicated if your heat gauge isn't straight up the ECU isn't reading the correct sensor inputs for optimum horsepower.

You will NEVER generate enough heat in the pits at idle (or other) fast enough to just go right out on the track without a thermo. (BTDT)

BTW did you know the E-51 "Supercharged" self-oiling transmission which fits your 4a series engine is a factory close-ratio unit, like
how about 3rd gear at the end of the straight?

Just a "passing" thought.

Supercharzed Toyz Raczing
S.E. Division, SCCA Racing
South Florida Sports Car Club

the e51 is considerably heavier than a C series.... also harder to find parts for if something were to go out. Best thing I ever did on my 87 s/c was remove the E51. Car is MUCH faster and handles MUCH better.

stick with the C series... cheap and they get the job done.

[d.vanheeckeren]

ummm...where exactly is the thermostat located? Mine didn't have one, and as my driver side window doesn't roll up (and the manual crank on the shaft of the motor was stripped when I got it), I really need some heat in this cold weather at 70 mph. I removed what I thought was the thermostat housing right above the alternator, but don't see a place for the thermostat. It's a 1982 4AGZE.

[d.vanheeckeren]

Sorry for the typo. It's a 4AGE. And it's also an 89, not an 82. Can you tell I've been up all night? *LOL*

[val]

The thermostat is attached to the top of the trans. (if u follow the tube from your overflow to its other end it should connect to the drain pipe on the t.stat housing. it takes a 10mm socket (or wrench) to take the housing apart. also takes a 12mm socket to pull the hole housing out, (which i find to be easier to get to the bottom 10mm bolt)

good luck

[d.vanheeckeren]

Ok, that's where I next suspected it was. I'll go try it now, started at 8 this morning (12 now) and haven't been doing much of anything but looking around with a confused look on my face. *LOL*

[d.vanheeckeren]

Thank you so much for your help! I got the thermostat changed, although instead of pulling the whole housing out, I found it easier to just pull the battery. I'll have to program my stations again, but it's much faster than trying to get to all that other stuff. Now I'm just waiting for antifreeze to get here (it's in my other car which was borrowed *L*) The guy who had this car before me didn't take care of it at all. When I changed the air filter, it was black, and when held up to the sun, you couldn't see ANY light through it. Got my mileage boosted by about 4 mpg just by putting a new one in. But not having a thermostat cut it right back down when the cold weather hit. It would warm up just fine in my apartment parking lot, but as soon as I hit 70mph, it dropped right back down to cold.

[brattesani]

make sure when you put in the coolant to bleed it correctly, you cant just put it in and go.

[toyotaspeed90]

the thermostat has nothing to do with the heater in the car....

if the car is sitting at the correct temps (about in the middle of the temp range) then it isn't over-heating and isn't under-cooling..... there's a problem with the heater-core or fan system...

[ag86IL]

Originally Posted by toyotaspeed90

the thermostat has nothing to do with the heater in the car....

Yes it does, if it stays open the car will never get full warm when it is cold. After the past couple winters with little heat I finally changed the thermostat last week, now the car warms right up. I'm almost looking forward to the winter because it will be toasty warm in my car.

[toyotaspeed90]

Originally Posted by ag86IL

Yes it does, if it stays open the car will never get full warm when it is cold. After the past couple winters with little heat I finally changed the thermostat last week, now the car warms right up. I'm almost looking forward to the winter because it will be toasty warm in my car.

sort of.... if the thermostat is stuck open then the COOLING system will be under temp.... not the fault of the heater core and lack of heat in the car... you will also notice the difference on the dash....

as I said previously.... if the gauge looks to be in the middle and normal... it isn't the t-stat