We have a 1997 4 cylinder LE Camry with around 85K Miles on it, and we are concerned that the engine is getting to hot, and the cooling fans are not working correctly. (We live in Florida it's not cold outside)
The engine light is on we had it looked at with a P0440 fault in the Evap Emission System not too concerned just putting as much info as i can about the car.

The car first started overheating around NOV last year and first thing we noticed was the coolant fluid was thick dirty and sludgy so we did some research on how to change it. So we kept changing the cooling fluid till the water ran clean took around 8 or 9 times then we drained and put the coolant in as well as a new thermostat, The car is running much better but we are still noticing the temp is getting way up there.

Both fans turn on and intermittently when the car is in park and just sitting there. The fans turn on when the AC is on. The fans turn on when the sensor connector at the radiator is unplugged. But we are concerned that when we are driving the fans are not on enough the car gets hot (nearly to the top hot mark on the gauge) and the fans turn on but then they turn off before the radiator cools down enough to be at normal running temp (about 1/2 temp).

Our concerned that the cooling fans are not working correctly and would like some input from other more knowledgeable people

Thanks in advance

 

Don't let the temp gauge get into the red or a head gasket might blow or head crack!

The fans should turn on/off when engine idles. When idling does the temp gauge needle stay steady at the mid mark as it should?

The fans should run with the AC is turned on AND compressor is running. The fans cycle on/off with the AC compressor engaging,

Any chance the engine was overheated leading to a blow head gasket which may have caused the dirty/slug coolant? A blown head gasket can cause over heating.

Were any radiator cleaner chemicals used?

Remove the radiator and let engine idle up to operating temp. The fans should turn on a around 199tF.

You can unplug the temp switch at the bottom of the radiator to turn the fans on. Then drive engine to determine if it still over heats..

 

1st - No luckily the head gasket did not appear o be cracked the coolant was not disappearing or any sign of the oil looking like coffee and needing to be topped up. It was just many years since it was ever changed

2nd - The fans should turn on/off when engine idles. When idling does the temp gauge needle stay steady at the mid mark as it should. Yes they turn on/off when engine idles and the temp needle stays around the 1/2 way mark. But when we are driving in slow traffic its going up to say the 3/4 mark so we been pulling over and monitoring what the fans are doing, the fans turn on and the temp drops a little but then they turn off again before the temp has gone down very much, and this is what is concerning us. Why are they turning off while the temp is still around 3/4?

3rd - Were any radiator cleaner chemicals used? Yes we used Prestone Total Cooling System Cleaner the first time we flushed the system and followed all instructions on the bottle, we were a bit hesitant to leave it in very long (we left it about 1/2 hour + the cool down time) since it has the original radiator we were worried it might be a little harsh and create a small hole were there were none previously.

4th - Remove the radiator and let engine idle up to operating temp. The fans should turn on a around 199tF. We have no way to know what temp the fans are coming on but they do come on but as above in red why are they turning off to soon?

 

The fans are turning off at the ¾ indicator mark? Do you know this for a fact?

Fans should turn on at 199F and off at 181F. Use a thermometer in the radiator fill port to check temps.

There is only one radiator fan temp switch on the 4 cylinder. The fans turn on when the switch is open and not when closed. If the switch electrical plug is removed the fans should turn on. Perhaps there is some kind of wiring issue causing a short.

Note the fan wiring is designed to either operate the two fans in parallel or series wiring as high and low speed. High speed is when the coolant temp is high and low speed is when the coolant temp is normal AND the AC is on.

Is the engine coolant really getting as hot as the dash gauge indicates? The gauge uses a different sensor.

Did this issue start after using the flush? Has happened the chemicals cause debris to break loose and overheating.

As stated pull the temp switch plug to run the fan full time and determine it the indicated temp becomes lower. Or, when the temp indication climbs above normal turn on the AC at max which should cool things down a little.

Did you install the T-stat (82C temp) with the jiggle pin or hole aligned with the protrusion at the top of the T-Stat intake flange?

 

The fans are turning off at the ¾ indicator mark? Do you know this for a fact? Yes we pulled into a carpark when the temp was up 3/4 and opened the hood and watched it do it. the fan was turning on and off, but that's why we are questioning if it is working correctly because we would of thought if the car was that hot the fan should be on. We disconnected the fan sensor plug on the side of the radiator so the fans were on all the time and drove home, the temp drop to the normal 1/2 way mark.
The thermostat we put in was 180 Fahrenheit i looked up the conversion to Celsius and that's about 82C and it would only fit one way so we could not mess that up.

Is the engine coolant really getting as hot as the dash gauge indicates? This is an interesting question and when we drive the car tomorrow we will take a meat/ grill thermometer with us and check the temp if it starts getting warmer then we would like. Will update on the outcome when we get home tomorrow

Did this issue start after using the flush? Has happened the chemicals cause debris to break loose and overheating. No the issue started before that's what prompted us to check the coolant and do the flush

As you can tell the car has very low mileage (around 85k) and only used for local driving about once or twice a month most of the repairs we do is because of age not because of use

 

We took the car out for a drive today but we did not seem to have a problem with the temp. The most it got was slightly above half and when we measured the temp in the overflow bottle the temp was 130.5f , not sure if it was just a slightly cooler day or what to think actually. We have a much longer trip next Tuesday Jan 21st , so we will keep the thread updated on the outcome then

 

Use that grill thermometer to check coolant temp versus gauge temp at mid gauge reading and then at 3/4 if possible. You can block the radiator with cardboard.

A mid gauge reading is normal. If the coolant system/fans are working normally the needle should STAY there .

Could be a bad temp sensor on radiator.

How is the coolant flow. Rare but the lower radiator hose can collapse.

 

Here is the outcome to yesterdays drive.

We drove to our appointment about 45 mins and the car ran fine and no issues with the temp.
On the way home traffic (bumper to bumper) was terrible it took about 3 hours to do the same trip home. weather conditions freezing cold pouring rain.
We were about 1/2 way home and we stopped at the post office the car was idling for about 1/2 an hour and my husband could hear the fans going on and off. After we left about 2 miles down the road we noticed the car was getting really hot nearly to the red on the dash gauge so we pulled into a gas station and checked the temp with the thermometer in the overflow bottle. its was 163F we turned the ac and heater on full to try to cool it down but it was not going down. We turned the car off and unplugged the radiator fan switch so the fans would go on. when we turned the car back on the dash gauge was saying 1/1 (normal) so we turned the car off again and re plunged the radiator fan back in.
We drove about 5 miles and the dash gauge again was saying it was really hit on the H it took a little while before we could find a safe place to pull over and check it. The fluid was bubbling out of the overflow bottle and the temp was reading 184F the fans were going but we had the AC and heaters going. Standing in the rain freezing we just turned the car off and unplugged the radiator fan switch so the fans would go on. We turned the car back on and waited a no longer then 60 secs and the gauge was reading 1/2 normal then drove home for the rest of the way home the dash temp gauge stayed in the 1/2 (normal).
This part is really confusing because how can the gauge go from 184f to normal so fast?

I have checked the fluids this morning and it does look like we are lucky enough not to have done a head gasket.

How is the coolant flow. Rare but the lower radiator hose can collapse. I don't know how to check this

 

When the temp gauge was getting up there and you stopped to check were the fans running?

Has the radiator cap been replaced?

A bubbling over coolant reservoir is not good.

One can test for exhaust gas in the coolant (head gasket or cracked head) by doing a block test. Search internet on "block" test.

https://www.google.com/search?client...e&q=block+test

Any coolant in the engine oil or spark plug tubes?

Exhaust gas in the coolant heats the coolant up fast.

 

This part is really confusing because how can the gauge go from 184f to normal in 60 secs?

When the temp gauge was getting up there and you stopped to check were the fans running? yes they were running because it was cold and we had the heaters on and ac to unfog the windows

Has the radiator cap been replaced? Yes the radiator cap has been replaced recently

A bubbling over coolant reservoir is not good.

One can test for exhaust gas in the coolant (head gasket or cracked head) by doing a block test. Search internet on "block" test.

https://www.google.com/search?client...e&q=block+test Thank you we will be looking into this

Any coolant in the engine oil or spark plug tubes? So far no sign of coolant in the engine oil or vise versa as for the spark plug tubes I dont know at the moment

Exhaust gas in the coolant heats the coolant up fast.