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Hello, I have a 1999 Toyota Camry with the I-4 2.2 Engine. (5S-FE)
My engine does always seem to run cold for no particular reason. I noticed that it happened slowly over the course of months the car would run a bit colder and just a little more cold next week. I Thought the Thermostat was stuck open.
So I just changed it with an aftermarket one. Took it for a test drive and Still the same thing. Replaced it again this time with a new OEM Thermostat. It helped a bit more but still much too cold. Other things I have done is check the Coolant Temp sensors. I have 2 of them One is for the ECU and one is for the Gauge on the Instrument cluster. Both appear to read the same. ECU says it runs about 145-160F.
I took an inferred thermometer to the engine and I get almost the same reading. My heat also does not work that great. In Traffic everything is nice and warm and great.
Im at a loss of what I need to do. Cooling fans Turn on as they should at 205F and turn off around 190. I threw cardboard in the Rad and that has helped a lot.
Thanks for any help providedThings I have Done:
Removed Air In cooling System twice
Changed Thermostat (New OEM is Installed)
Checked Coolant Temp Readings
Compared Coolant Readings to Actual Engine Temp
Checked Fan Relays
Cardboard in Rad.
Changed Coolant temp Sensors with known working
Checked for Codes Stored and Found none
Using 50/50 ish Collant Mix
Checked make sure belt is going right way
Removed Thermostat and saw Further Temp dropThis Video should be Helpful too.
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Ok, looked up at what direction it supposed to spin and it is correct. Can’t think of anything else…Cars don’t just run cold, there must be something i am overlooking.
LOL This problem, as you’re describing it, is only caused by one thing: the coolant is being allowed to flow to the radiator with out restriction. Which, if the coolant is flowing the correct direction, is the sole purpose of the thermostat.
I have a feeling there is a key piece of information that we are missing. You never answered whether there are codes coming up when you have your scan tool hooked up.Ok, I made this Video Maybe It will Help Maybe It wont. Its showing that My Temperature is Dropping Despite no Coolant that seems to be moving. Drive time was about 15 Minutes. And the Weather was around 70F. And No Stored codes where found. I tried to Remove all Cardboard but One piece was stuck. Something too add as well I have a friend who I got a reading from Camry his car runs Steady at around 190-200F While traveling down the road. With the Heat ON it usually drops further. If nothing else it will benifit me in the Summer when its like 90 outside.
I have been following this thread for a while so I thought I would chime in.
In your first post, you say the fans come on at normal times. I.E. Fan(s) are not running all the time correct? Because Toyota uses a sensor (Switch) on the bottom of the radiator to monitor when to kick the fan on. If it gets disconnected or goes bad, the fan runs all the time.
You say you have gotten all the air out and from your video when hot it does not like like there are any bubbles, so that looks OK…
You have replaced the thermostat several times… including with an OEM one. This is where I think this issue is centered around. Since you cannot put the thermostat in backwards on this engine it is very suspect to me… Did you install the bleed hole at 12 o clock? Since it is so easy to remove the thermostat on this vehicle I would consider removing it (albeit temporarily) and see if anything really changes…
How do the Heater core hoses feel… (Are you running the heat on max?)
Check to ensure the heater control valve moves fully open and closed….. The clue that you are not getting good heat lends creedence that there is low coolant/air in the system…. May want to flush the heater core…
I would start (as I am sure you have done) by:
Ensuring cooling fans are not running full time (I.E. when you start the car cold)
Pressure testing the system. Ensure it holds pressure.
Inspect the heater core valve and ensure it opens and closes completely.
Put a spill free funnel on it and running heat on high and ensure valve is open…and bleed the system again.
If that does not work I would remove the thermostat housing, check for bleed hole at 12 o’clock, remove and inspect it and reinstall without it and see what occurs…
Good luck
-Karl
If the electric fans are coming on and off at the appropriate temperatures and the thermostat and sensors operate normally when sitting in hot water, sounds like all is well with those and there isn’t anything wrong with the coolant lines. Ditch the cardboard. That can cause more problems overall. Your car wasn’t designed to run with a restricted airflow, it’s not a diesel. What is most likely the problem, if your main fan is not electric, is that the fan clutch has failed. It is supposed to tighten up to reduce fan speed and thus reduce the air flow over the radiator. If it isn’t tightening up when it is supposed to, then your fan is running too fast causing the over-cooling. If all of your fans are electric, then of course that isn’t it, unless there is an electronic fan speed control. I’m not familiar with your model. I’m just throwing out some ideas. Also, make sure there aren’t any air pockets in your cooling system.
It only has electric fans and even if the fans were running nonstop the thermostat would keep the engine at an appropriate temperature by restricting flow into the radiator (just like it does in the dead of winter or the peak of summer).
“even if the fans were running nonstop the thermostat would keep the engine at an appropriate temperature by restricting flow into the radiator (just like it does in the dead of winter or the peak of summer).”
No, the thermostat will NOT adjust to changes that quickly. It takes minutes for the piston in the thermostat to move due to the wax inside having to melt/solidify. The car reaches normal operating temperature standing still, and only overcools while in motion, if I read all the posts in this thread correctly. That indicates that too much air is traveling over the engine (hence the statements I made about the fans) or the coolant is not flowing correctly.
Has a scan tool or external temperature gauge been attached to the car and OBSERVED while DRIVING the vehicle when it is overcooling? It wouldn’t be the first time someone has chased their tail over a non-existent problem due to a wonky gauge or sender that appears to work statically when tested but fails during actual operation.
You are incorrect. The thermostat keeps the temperature steady by constantly adjusting how much coolant goes to the radiator. It doesn’t take “minutes” for it to adjust and even if it did “too much air on the engine” wouldn’t make the engine too cold. The thermostat keeps the engine temperature constant whether the outside temperature is 0 degrees or 100 degrees.
Engines get to operating temperature no matter if they are moving or sitting still. If what you are saying is true than engines in cold climates would never reach proper operating temperature.
There are plenty of people who bypass a bad temp sensor and the fans run constantly. They don’t have this problem.thisisbuod, I guess we will have to agree to disagree. Meh.
I still say the OP needs to attach a scan tool or external temperature gauge and observe the temp reading while the vehicle is being driven. That way there is conclusive evidence to what is actually happening under the hood in operating conditions and not while parked and idling.
Alright then, I do have footage of me Driving but I decided to cut most of it out on the Final Video. If that is what you are looking for (Me staring at the scan tool while driving) then I have done so. Also in the Past I have used an IR thermometer under the hood as soon as i stop. I have More footage if you neeeed it. But the temp says at around 150ish if its 70F outside. When it was in the 20s it got down to the 130s
in the unused footage I compare the Gauge to the ECU Temp. And just for fun I unplugged the ECU sensor and Check Engine came on within 1 second.
Sometime this afternoon when I get Done with work I’ll Remove the Thermostat And Compare.
I’ve watched thermostats work in the engine. Sitting in the driveway with the pressure cap off, once up to temperature, I can tell both by seeing the flow in the radiator and a change in sound from the water pump when coolant is flowing. I wouldn’t say it is instantaneous but the thermostat will open and close several times per minute at idle. So, it is a fairly active device. On the road with greater heat loads on the engine I’d expect it to be more active but I have no actual knowledge.
My guess, and it is only a guess, is that something associated with the thermostat housing has corroded out and coolant is bypassing the thermostat. The other possibilities I can think of are automatic climate control gone bonkers or other problems in the heater box.
I ran into one case where an owner had gotten an aftermarket thermostat and it was too small. He used it anyway – just dropped it into the housing.
This is really boiling down to a t-stat issue. You did use a new rubber o-ring, right? I’ve seen sometimes where they get left off, or a damaged one is re-used, or RTV used instead, causing coolant to flow past the stat when it is supposed to be shut, mimicking a stuck-open stat.
It is a new Gasket. And its nice and tight. It can’t fit anymore perfect.
So Today I removed the Thermostat all together and Put everything back together and Drove around for around 15min. The Temp stayed around 130-140. Witch is odd. Coolant was for sure moving as soon as i started the engine. (Unlike in my Video) I made a video but I don’t feel like editing. So With the Thermostat installed coolant is Somehow cooling but Its not Moving? (Check Video) That can’t be right.
[quote=”Icebeam47″ post=130630]The Temp stayed around 130-140. Witch is odd. [/quote]
Not odd for having no thermostat installed.
So With the Thermostat installed coolant is Somehow cooling but Its not Moving? (Check Video) That can’t be right.
Some coolant is supposed to circulate through the bypass circuit until the engine warms up, opening the stat, which in turn shuts off the bypass. Perhaps the bypass isn’t being fully shut off by the t-stat when it opens up (obstruction? corrosion in the seat?). If the water doesn’t get hot enough to open the t-stat, there will be very little movement, if any, visible at the radiator.
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