SDHNTR

Getting fed up now, big time. I've burped the hell out of this thing. Drove it for 50 miles, thought problem was solved as it didn't happen most of the way. Then 2 miles from home it gets hot. What gives? What else could cause this problem if it is not air in system and it is not the t-stat? What to do next?

sam333

How high is the gauge getting, is it just in the upper range of "normal" temp, or ist it actually overheating? Are you sure that your gauge and sender are acurate? Is it only over heating in stop and go traffic? Have you checked your fan clutch? Is your engine new ( rebuilt)? If you are actually overheating you might have a blown head gasket ( you can buy a block checker to test for combustion gases in your coolent). An IR temp gun will go along way in seeing if there really is an overheating problem.

SDHNTR

The gauge gets maybe 2/3 up for a minute or so, then works back down to normal. Never reaches the red. Motor is a new rebuild with about 150 miles. Fan clutch is fine, coolant sending unit is new. It does this randomly, not under any certain driving condition that I can identify.

I have not verified gauge, but I do know it never did this before with the old motor. With the old motor I never once saw the gauge go over normal. I'm just baffled the dual stage thermostat didn't fix it as this sure seems like temp gauge overshooting and everyone else who has had this problem seems to have fixed it with the dual t stat.

sam333

At 150 miles your still breaking the engine in , and if it was built tight your going to have even more heat. Your not over heating so thats good. If you are really worried about it ( it sounds like you are) I would test your gauge, also is your sender a toyota part and do you have a good ground at the block.Going from the middle of the gauge to 2/3 is a very small temp rise. Again an IR temp gun will tell whats really going on. You are not loosing any coolent ,right? Your heater core/ radiator is not leaking, no smell of coolent in the truck? You can have a leak so small that you will never see coolent leaking( but it will let air into the system).

SDHNTR

Thw problem with the temp gun is that it only happens while running. If I were to try and check the temp, I'd have to pull over as soon as it happens and by that time it will have already cooled down.

From everything I've read this is a classic case of temp gauge overshooting as cooler water comes back from the heater core. I'm just baffled why the new t stat didn't fix it.

874runnersr5

tomorrow ill be draining my system and refilling it with a coolant vacuum filler, ideally my system should have no air and wont over heat... ill report back and let you know.

SDHNTR

Yes, please do let me know how it goes. I'm not familiar with the process you are referring to, but I'm willing to try virtually anything.

I've resorted to just closing the heater control valve (it never does it with the valve closed) but I'm getting tired of shivering my way to work.

874runnersr5

Its really handy, it assures that there is NO air in the system, it runs off a air compressor like most tools and creates vacuum. Then you have your fill hose thats in a bucket and then you open one valve and it replaces the vacuum with coolant.

SDHNTR

Cool. Let me know how it goes.

874runnersr5

haha of course something else happens when i work on my truck, i broke the weld for the upper rad mount off the rad lol. anywho, drained it, hooked up the tool, the guage wasnt working i think.. or something because i had all hoses colasped and the guage was at 0 still.. so im not sure but i refilled it, burped it on my ramps just for good measure took it for a drive and watched my guage, im 99% sure it didnt move at all from its regular place.

Tomorrow when i drive to work will be the final test, so ill tell you.. but so far it seems to work

SDHNTR

well, fingers crossed! Where did you get that gadget? How does it differ from the machine the quicky lube joints use? My local one only charges $50 for a coolant exchange so I might just go that route if it's the same process.

Ezrider_92356

i had that problem and just drilled a 3/32 hole in a aftermarket t-stat to let just a little coolant flow threw it. what happens is the return line for the heater core dumps out right before the t-stat and keeps it from opening when it should. try running with your heater off (if you can bear it) and see if it does it then.

SDHNTR

I'm well aware of that Ezrider. This only happens with the heater control valve open. I already changed out the t stat to a dual stage one attempting to address the problem. One would think that would essentially do the same thing as drilling a hole and solve the problem, but not in my case.

So has anyone else had this problem, changed to a dual stage thermostat with no resolution, and then tried going back to a single stage with a hole drilled in it? Did that then solve it? I'm wondering if the hole solves this probelm better than the dual stage t stat.

mightymouse

iTrader: (6)

SDHNTR, you're making a mountain out of a mole hill. When you "burp" the cooling system, Make sure the vehicle is on an incline
Use a funnel that fits snugly into the opening of the radiator,
Pour in coolant until the motor is full, and a little extra in the funnel
keep funnel in place.
Start the motor with the cap removed and funnel still in the "fill" position
While the motor is running with the heat on and the heater valve open allow to run until the t-stat opens.
when the t-stat opens you will watch the coolant empty into the motor as it starts to circulate and add coolant until the coolant is topped off at the point of the cap.
when the motor's coolant is topped off and is running at operating temp remove the funnel and secure the radiator cap.
Make sure the coolant resevior is at the correct level and call it good as you have just successfully "burped" the coolant system on a 22re.
This is not a difficult process just takes a little patience.
Once you have done this you should now be able to say by process of elimination that your t-stat is functioning properly and coolant flows through the radiator and engine block correctly.
After that it can be only a few things when concerning the cooling system of the good ole 22re.
1 being the cap and another being the fan clutch (i hope you replaced the fan clutch on a new motor) it's a good idea and can be bad if you don't in the long run. I know this one from experience. Another good thing is to pressure test the system as well to look for leaks internally and externally.
To be honest i'd run it. My truck has the regular t-stat and of course it gets the fun temp overshoot just like yours. If your really that concerned get the fan clutch and be confident your cooling system functions as it should.

SDHNTR

Fan clutch is fine. I tested it before new motor install. I've done the front end up on ramps burping thing a few times. This problem only happens when the heater valve is open so I'm convinced it's temp gauge overshoot (that still isn't solved with dual stage t stat) or stubborn air still trapped in the heater core.

Since I've tried the proposed usual fixes for both possibilites, I'm now at a loss of what to do. I refuse to believe this is normal. When functioning normally, the gauge should not get above the normal spot at just below half on the gauge. I'm willing to try anything.

mightymouse

iTrader: (6)

yeah seriously it's fine. Mine does it, the other two 22re's i've owned did it. Keep in mind as well the temp gauge in the good ole toyota isn't exactly all that accurate as well. I've had my fair share of trouble with that as well. So speaking from experience it's fine and you are fretting over little to nothing. Like the rest of us that have grown to love and rely on these quirky little 22re's just run it. Or keep poking around driving yourself nuts. If you really want to keep an eye on it get an after market temp gauge and watch it day and night loosing sleep if need be. Good luck man but i've been there this too will pass. Here's a thread for some light reading on my personal experience for justification of my comments. https://www.yotatech.com/forums/f120...issues-184271/

874runnersr5

i went out for a drive today after it sat for a couple hours, ran normal then my temp guage always sits a 1/4 mark, it rised a tad bit up and lowered back down.. didnt get to the top like how it used to.. oh well.

hoping its a cracked head or headgasket so i atleast have a reason to replace them next week with my new ordered parts lol.

Ezrider_92356

sorry i had missed the second page when i posted, when mine was overshooting before it probably would have gone all the way into the red if i would have let it esp on below 0 days i would have to pull over and shut the motor of until it heat soaked the t-stat then i would be fine until the engine got cold again. i actually drilled two 3/32 holes in mine. takes a extra block or two to warm up but does not over shoot at all anymore, a cheap t-stat at the auto parts store is less than 10 bucks and i'm sure you have plenty of practice changing them out by now...lol
if it is bothering you it might be worth a shot and worse case if its no better you now have a spare t-stat you can throw in the glove box in case of emergency.
i would be curious to see if there is any difference with the hole vrs dual stage.

GeeVee

I wish I had seen this thread months ago.

874runnersr5

Went out and got a cheap thermostat and gonna drill two 3/32nd holes into it, i have a new oem with under 2000kms on it inside right now and i need something to help it stop over heating until i do my headgasket this weekend..