Everything overheated

[riceter]

I was driving home (a mile from freeway) and check engine indicator comes on. It took maybe three blocks to find a place to pull over. Before I was parked the transmission related indicators came on (I believe the A/T OIL TEMP and VCS TRAC and VSC OFF). This is when I noticed the engine temp at 'H'. I shut it down. Before I left it, I checked radiator fluid and oil level which both seemed fine. Belt is fine and tight. Everything was acting normal before shutdown (other than dash lighting up).

After dinner I went back. It started right up. It was ow bellow the normal operating temp and no indicator lights were on. I drove the mile and half to home. Everything acted normal (noises, power,shifting) and obviously no time to overheat. The heater worked so it seems that the water pump is moving fluid.

Where should I start?

2000 100 series 140K miles.

 

[Supra88]

Thermostat, fan clutch?

 

[SanDiegoCruiser]

My vote is thermostat...

 

[TwiceWithHair]

Broken window motor?

 

[splacek007]

Own experience...

A Ford Bronco I owned intermittently "overheated" - it turned out to be a bad oil pressure regulator/sending unit (a $5 part).

The sending unit eventually started pumping oil out of the underside of the car as I sped down the highway (covering cars behind me in oil...). I don't know if our 100s have an oil pressure regulator or sending unit, but just a thought. Initially, the faulty unit did not pump oil out of the engine, it was just not working all the time and the temps. would slowly creep up. I even took it in - mech. did not find anything wrong until catastrophic failure! When half the oil was out of my engine I had one of those "I wonder whose car sounds like such sh--" shortly followed by "OMG - it's mine!".

Thermo. is another good idea. I thought they generally fail "open" (mine have) but I'm sure once and awhile they fail "closed".

 

[2001LC]

Possible Stuck Thermostat

Check ALL fluid levels first and make sure the radiator is filled to the top by taking off cap & coolant reservoir is between low & full. Then get the issue to repeat, while warming up engine check upper radiator hose to see when fluid start coming through by squeezing hose. You can also leave cap off radiator and see when fluid moves, but do not remove radiator cap if already hot. If fluid moves through hose/radiator before one would expect the engine to be warmed up, this would indicate weak thermostat, and the cabin heater will not get as hot as it should. A stuck closed thermostat and no or very litlle coolant will move, and temp gauge would read hot. Note you may get some coolant to over flow from open radiator when squeezing hose, so pack a rag around the cap, but keep rag & coolant away from belt area.
See: https://forum.ih8mud.com/100-series-cruisers/774060-strange-temp-gauge-behavior.html for similar issue.

 

[riceter]

So . . . Replaced the thermostat and did a Red antifreeze semi-exchange. My first test seemed like a failure as temp started to go above normal, but I wasn't getting any heat now. Hoping it was an airlock I checked again after dinner. The fluid levels in radiator and reservoir were down now, so filled them up again and tried it out. Success! Rock stable temps and heat.

A couple questions. My exchange could have been more complete if I had found the upper drain plug. Could only find one on radiator and back of engine. Any clues to finding it?

And, should I have the transmission fluid changed since the transmission temp light went on during the initial event?

Also - how come I didn't get an audible alarm?

Thanks for the advice - now wiser and back on the road!

Andrew
2000 LC 100

 

[2001LC]

So . . . Replaced the thermostat and did a Red antifreeze semi-exchange. My first test seemed like a failure as temp started to go above normal, but I wasn't getting any heat now. Hoping it was an airlock I checked again after dinner. The fluid levels in radiator and reservoir were down now, so filled them up again and tried it out. Success! Rock stable temps and heat.

A couple questions. My exchange could have been more complete if I had found the upper drain plug. Could only find one on radiator and back of engine. Any clues to finding it?

And, should I have the transmission fluid changed since the transmission temp light went on during the initial event?

Also - how come I didn't get an audible alarm?

Thanks for the advice - now wiser and back on the road!

Andrew
2000 LC 100

Flush coolant system without mechanical flusher (back yard mechanic), systems with rear heaters hold 16.3qt 50/50 mix of Toyota red & distilled water or premixed Toyota red:
Every 20K miles or 2 years; remove #2 under shield (plastic). Block drain plugs are on opposing sides of engine block, can be seen from underneath near backside of front wheels/tires. Use 10mm socket on block drains to loosen. For no mess use 5/16 ID hose to drain block tubes, 1/4' ID hose off radiator drain tube into jugs and you will get measurement of how much comes out. Drain ~12.2 qt out of 16.3qt, plus remove reservoir and clean. Then add 3 gal of distilled water or as much as necessary to fill. Tip: let sit with cap off for awhile on level surface, then add more as air bleeds out. Warmed up with front & rear heaters turn up to max (85 deg) (struckout as it is not necessary) running until engine hot and drained after short cool down. Add ~2qt of Toyota red 100% into radiator to mix with estimated 4 qt diluted coolant remaining in system. Then added 10qt of mixed (mixed before hand) 50/50 Toyota Red & distilled watered, plus fill reserve with 50/50 to fill line. Warm up and add more 50/50 to reserve after complete cool down, you’ll want to keep doing this each morning before starting engine (while engine completely cold after its reached operating temp the day before) until the level holds at the full line. Test should show ~-34 protection or 50/50 mix.


I doubt you transmission fluid is harmed, but smell it. That said I like to flush transmission with 12qt of M1 syn ATF each 30K miles depending on driving condition, and the power steering with 1qt more often with same ATF.


Audible alarm is when wife starts yelling at you for making mess and being late for…LOL.
No audible, that’s what the temp gauge is for.

 

[Trunk Monkey]

See what the CEL code is.