when i say indicator i meant a meter with an arrow going up and down from cold to hot

 

Yeah, I want an arrow. Thos eidiot lights are too little too late. Damage is already done when those are on. I am looking at putting in an oil pressure and water meter.

 

Long time no post, I lost this thread, been too busy working two jobs to sit down with my dial up and find it.

Anyhoo, I got a scan guage 2 and been driving in various traffic. Seems stop and go like when an accident occurs and all but one lane is closed in 40 degree weather my temp hits 200 degrees and goes over. I tried turning on the heat, but it still climbed with my just idling and going on and off the clutch tailgating the guy in front of me so no one cuts. I decided to try the ac to get the cooling fan to kick on and BOOM, my temp headed down to the 190s within a few minutes.

For the most part my engine temp runs from 179-184, but in heavy traffic it will climb to 190+.

My comclusion is that my sensor for the cooling fan is bad or the relay as it seems to only come on with the ac.

 

i should have came on with the heater too......

 

Your car is normal. The cooling fan does not come on until 204F. But the fan is interlocked with the AC above a certain temperature, so turning on the AC will turn on the fan.

 

Blown head gasket will pressurize the cooling system right away usually as soon as you give it some throttle under load and blow air into the coolant causing more overheating problems. The plug misfire is from coolant getting into the cylinder(s) and fouling the spark plug(s) from the leaking head gasket. There does not have to be oil in the coolant or coolant in the oil to have a head gasket leak - that would depend upon where the leak was in the heak and how much coolant gets past the rings to get into the oil.
Normal radiator fan on temp is 205 degrees according to my ScanGauge2 but running the heater on hot and NOT recirculate will bring the temp down below 160 at idle normally on a cold day. I have to run a grill block to get enough heat in my xB duriing the cold months or else the heater cools the engine too much.
A simple fix would be to retorque the head bolts.

 

I have noticed that my '06 takes a long time to warm up in the winter. If running around the suburbs with the heater blasting lukewarm air, and doing lots of 15-minute errand stops, it often only gets up to 160F before it's time to stop again. But if I can do a run downtown on the Interstate, it will get to 186F and stay there in city driving with the heater blowing red hot.

 

my car doesn't do that it'll stay at 184 degrees with my heater on full blast untill i get hot then i turn it down to the half way point...

 

My car stays at 184 degrees, too. Once it gets up there, it stays there as long as I am driving it, and the heater gets so hot that it has to be turned down.
But on a frigid morning, if I drive a couple of miles, park for 15 minutes, drive another couple of miles, park for another 15 minutes, etc, the car will not reach 184 degrees and the heater will not get hot enough to have to turn it down.
I would not know this without a ScanGuage, because the car does stay over 137 degrees where the blue light goes out.

 

Yeah, over heating issues and head gaskets go hand in hand. From my experience at a machine shop- that is what I would do next after checking or replacing the stat, coolant, flushing the system and checking the radiator.

Humm,,,,,, So the stat opens at 180, but the fan comes on at 204. Maybe I am missing something here?

My temp is all over the place like the stat is bad. It seems once I get above 181 it will stay warm. If its a cold day out, soon as I come to a stop it cools down to 160 or less. I arrived to work too early one day it was sleeting out to avoid the accidents. I just sat there pulsing the throttle ever few minutes and the heat on. Man, my temp went right down.

I blocked off the radiator in my old mercedes diesel that had a temp meter and man, it warmmed up faster and stayed warm on the coldest of days. Infact even in 70 degree weather without heat on, it kept its cool. No matter what, it would run hot in 95+ degree weather with ac on and without the radiator blocked off.

If I did not mind getting messy, I would replace my stat with a warmmer one like 185-190 and refill it with the correct antifreeze.

 

you don't want to run the engine hotter than the 184 - 190 degrees or else the R/F mix will go rich to help cool the engine. It really depends upon how good your engine is running - I get in the mid 40 mpg even in cold weather and today I hit 50.2mpg on a trip to Tiverton so you can imagine that I am burning about half the gas some of you hot engines are burning so I get less heat to play with. I have an opening in my lower front grill about an inch bigger then the liciense plate bottom to let air through the radiator and I manage to keep the engine over 177 degrees for most of the trip. If you have a slow heating engine keep the heater off as long as you can stand it to let the engine warm up first then run on recirculate to get the max heat out of the heater.

If the engine temp is jumping all over the place and getting too cold then you have a leaking thermostat. Normal engine temp is about 184-186 degrees with proper radiator air flow and no heater use.

Sorry darn IBM keyboard has all the keys slightly off center.

 

^^^yep scan gauge makes us all paranoid LOL

 

Thats the main reason I bought an sg2. I wanted to know what was going on as the idiot lights give too little warning. When they come on, you always screwed something up.

I know last summer when my little blue light would come on for a few minutes then go off and with my ac on my fan dipped into high speed started to get me concerned. Then this year I heard the fan pop on in stop and go traffic and see smoke from what looked like under my hood and the water level low.

When I headed to a trip to Manasses VA going 90 for 30 miles tailgating an xb, I checked under the hood after the trip and could see where water boiled from the thermo cap and got all over the intake manifold. Of course I added more water, but did not want to block the radiator til I knew what it was doing.

I normally wait til the blue light goes off to turn on the heat, however I find it heats up faster and stays warmer on outside vs inside air on my xa.

 

You should check your Cabin air filter in the heater for blockage since it filters outside air and not inside air if you get less cooling effect with the outside air. You might also crack a window open to let the air flow more easily when running outside air.
As for the over heating the BIG NO NO is adding water to the radiator!!! First you never add water! only the Toyota premixed coolant because any contamination in the aluminum alloy engine will cause all sorts of corrosion problems in the radiator and block. And second you don't open the radiator cap . . . add coolent to the over flow container only. Opening the cap will damage the outer seal and cause leakage between the overflow container and the radiator and allow air into the block and radiator instead of the drawing coolent from the overflow container.

SG2 is definately the way to go - just wish I had the latest updates to the software - going to have to put the SG1 in for a week and send the "Early 2006" SG2 back for updates.

 

i've open my radiator cap all the time, and i don't have any problems with that what so ever

 

Yeah, I know about the cap vs over flow tank. Not the first car I have owned with one. The leak seems to be from the capand I assumed it boiled over. I removed and installed the cap when it was cold and it seems to have a good seal and when I checked after driving one day it did not leak.

The dealer had me add bottle water to the expansion tankto bring it to the full mark. Hows that?

 

If it was not double distilled it was the wrong stuff - bottled water has lots of minerials in it and is bad for the block and radiator. Our bodies need minerials but not the cooling system. Usually the radiator cap allows expansion of the coolant into the overflow bottle and it should not boil over. It would boil over if the pressure cap failed or you exceeded more than 260 degrees or more depending upon how much water you added to the coolant to lower its boiling point and the pressure of the radiator cap. If your head gasket is blown then you were pressurizing the cooling system with way too much pressure (aprox. 12 psi cap) and blowing the coolant out but is should have gone into the expansion tank and then overflowed from that not the radiator cap. Make sure you have the cap screwed on all the way - there usually is a double stop - one to release pressure and all the way on to pressure seal the radiator.

 

Lets face it Jan, the techs at the dealer I use are k-i-n-g idiots.

Yes, it was boiling out of the rad cap. I was shocked too as to why there than the over flow bottle, but this car unless I am missing it, does not seem to have an over flow tube that goes from the rim of the cap so when it starts to blow off steam the moisture is bubbled through the over flow tank.

 

It shouldn't be be blowing off steam - if it is then the coolant needs to be replaced as it should not boil unless over 260 degreed F. Maybe you should take a sample into the kitchen and boil some on the stove with a cooking thermometer in it to check the boiling point. If you get a high boiling point then you definately have a head gasket problem . . . and probably are getting the cooling system presurized as soon as the engine starts up.
There should be a hose out the side of the radiator neck just below the cap to the overflow bottle and then there should be a hose down the side of the bottle towards the ground. Coolent is considered hazardous waste btw. Thermostat check is also a good idea to make sure it is opening at the correct temperature. If you have a 200+ degree thermometer you should check the radiator temp with the engine running to make sure it is getting hot and circulating the coolent when the engine gets up to 184 degrees. You can also remove the radiator cap when the engine is cold and watch for bubbles right away when you start the engine - that would also indicate that the head gasket is leaking. As the engine heats up the coolent will expand a little and run into the overflow bottle and when the engine finally gets hot it should start flowing through the radiator without boiling over.

 

Is 134 degrees celcius for the coolant temp normal?