Radiator burping problem..
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octanejunkie
Elite Member
NO
Are you sure the thermostat is installed correctly, and properly functioning?
Once it settles down add more coolant till the radiator appears full
Elevate the front of the vehicle slightly, park on an incline, then fill the radiator FULL with coolant and run the heater full hot, full fan to allow coolant to flow through full capacity of cooling system. With cap off, watch for coolant to flow inside radiator, thermostat open. Keep adding as fluid as necessary till coolant level is about 1/2" from the top of the neck
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Beaumont67
New member
On an empty rad. - run the engine while adding antifreeze, to remove air locks.
Topping up a rad. - add the antifreeze, and wait 5 minutes before installing the rad. cap...air bubbles will rise to the top & escape.
^^ This is how I did things, decades ago...but rarely do I have a radiator problem now.
Topping up a rad. - add the antifreeze, and wait 5 minutes before installing the rad. cap...air bubbles will rise to the top & escape.
^^ This is how I did things, decades ago...but rarely do I have a radiator problem now.
19963.4lsr5
New member
As the temp of the coolant rises it expands. It will expand enough to push out the filler neck. I always fill the rad as far as I can. Then start engine and let it circulate. I'll add coolant if necessary to keep 1/2" air pocket below the rad cap. When the coolant starts to push out I put the cap on and let the purge valve do the rest of the work. You shouldn't need to burp a properly operating cooling system. Fill it as full as you can, and fill the overflow tank to its max line and when the coolant expands enough to push out the top put the cap on and let the purge valve in the rad cap do the rest. After 3 heat cycles you should be done. During those 3 heat cycles remember to keep topping off the expansion tank.
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Sup41
New member
That's helpful! Thank you. When you say heat cycles, you mean fill, turn car on, heat, repeat?
SilverRidgeRunner1
Member
Are your Running the Heat full blast... If not that will help as well , also this little jewel will help tons
19963.4lsr5
New member
Heat cycles are hot to cold. And after the initial fill and I finally put the rad cap on I drive it. That equals heat cycle number 1.
With a cold engine you should be able to squeeze the upper radiator hose and hear coolant push through the rad cap and into the expansion tank. That vent valve in the rad cap is how the rest of the air gets purged out of the cooling system.
As you drive after filling the cooling system any air left collects in the upper tank of the rad. Then, After the system cools and the vent valves opens up..........you start the engine again with that air pocket in the rad...... As the water volume expands because the engine block is getting hot the air is pushed out the rad cap until hot coolant starts flowing through it. Hot coolant causes the valve to seal and preventing any flow into the overflow tank.
The flip side is as the engine and coolant cool off its volume shrinks. That in itself causes a vacuum and draws coolant from the expansion tank back into the radiator. So the air gets pushed out and when cool coolant gets sucked back in.
The jigger valve in the thermostats main purpose is to allow air to push up through the tstat and heads and into the upper rad hose while filling. In theory the coolant circulation should push the ball of the jigger valve against the t-stat and seal the hole. Why its position matters to the tune of 10-20 degrees gets me.
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BrianSD_42
New member
In addition to all the advice already stated I'll say this ..... PHONE A FRIEND or more importantly convince a friend who has done this before (and knows what they are doing) to come over and help.
I had a bunch of problems with burping and the simple advice didn't work.
I had a bunch of problems with burping and the simple advice didn't work.
I have never, ever worried about "burping" these rads and never had a problem.
I fill it up and run it a bit with both heaters on hot.
I do disconnect the top rad hose and use that to fill the block though.
Then over the next few days make sure both the rad and overflow are at the right levels and then not think about it anymore.
I fill it up and run it a bit with both heaters on hot.
I do disconnect the top rad hose and use that to fill the block though.
Then over the next few days make sure both the rad and overflow are at the right levels and then not think about it anymore.
19963.4lsr5
New member
And the other important thing is to drive it to push the air into the Rad so it can be pushed into the expansion tank on the next heat cycle. Just idling the engine isn't going to circulate the coolant fast enough to push the air into the rad.
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Are your Running the Heat full blast... If not that will help as well , also this little jewel will help tons
I have one of these it works great. I also have a tiny one for bleeding my mtb brakes!
Vansnxtweek
New member
There has been some good advice given..I'll add with my experience.
I did my head gaskets so upon starting I was obviously super nervous. I filled my radiator until it was about full to the neck, put the heater on wide open, started the truck and let it run while I watched the fluid. I didn't add any to the reservoir at that time. I let it warm up constantly checking the temp gauge. As it got hot the level rose and it bubbled some so I just put a rag over the empty hole until the level dropped down(when the thermostat opened) and then I topped it off and put the cap on. I went ahead and filled the reservoir to F. From then on I've had no issues. I've checked my level a few times afterward.
Side notes, its important to orient the thermostat correctly with the jiggle valve on top. I also check the top and bottom hose to compare temperatures to ensure coolant is flowing.
The funnel looks like an awesome idea. Wish I would've had that.
And yes...air pockets in the coolant system are BAD.
I did my head gaskets so upon starting I was obviously super nervous. I filled my radiator until it was about full to the neck, put the heater on wide open, started the truck and let it run while I watched the fluid. I didn't add any to the reservoir at that time. I let it warm up constantly checking the temp gauge. As it got hot the level rose and it bubbled some so I just put a rag over the empty hole until the level dropped down(when the thermostat opened) and then I topped it off and put the cap on. I went ahead and filled the reservoir to F. From then on I've had no issues. I've checked my level a few times afterward.
Side notes, its important to orient the thermostat correctly with the jiggle valve on top. I also check the top and bottom hose to compare temperatures to ensure coolant is flowing.
The funnel looks like an awesome idea. Wish I would've had that.
And yes...air pockets in the coolant system are BAD.
Kanoe
New member
No. Nothing on the thermostat gasket. It's not a cheap paper gasket like some other makes. It's a rubber ring that slips on the circumfrence of the thermostat. Just assemble it as it comes.
Only sealant you might want to use is a little thread sealant on the block drain bolt, but even this is not likely needed. (I did use a drop)
phattyduck
Elite Member
The filling technique you use works on 90%+ cars/trucks on the road. That's all I had to do to my 4Runner after water pump / radiator replacement... The exceptions are usually mid/rear engine cars or turbo motors with odd cooling systems.
The heater should be set to full hot, but the fan doesn't need to be on high or anything (on SR5/base models, you don't even need the fan on!). Also, the rear heater always has full fluid flow - the temp control is a flap that directs air through the rear heater core or around it. So, no need to turn on the rear heater or adjust the temp there.
BUT! The jiggle valve on the 5vz-fe (V6) motor should be at 6 o'clock (confirmed in the Factory Service Manual). If it is placed as the top, the engine runs 10-20*F hotter than it should. You can't see that difference on the stock gauge, so most people don't know that their truck is running hotter than designed.
-Charlie
Kanoe
New member
No to those listed above. There are automotive thread sealants intended for these type of plugs or oil pressure switches etc. I don't have it in front of me at the moment.
Truth be told, on one car I used it and on the other I didn't. Neither leaks.
When I did the t-belt, water pump, and t-stat; i was getting tired and did a quick search. installed the j-valve on the t-stat UP. (i know i know. DOWN).
the 4runner ran at 200F without fault.
a little over a year later when i re-replaced my t-stat while i added good antifreeze, i simply reinstalled the new one just as the old one came out (up).
i used a slightly cooler t-stat and the 4runner runs at 190F rock solid.
i am debating on going back in there to rotate it DOWNWARD after actually reading the proper procedure.
but more to the point, i used a 4 inch section of garden hose between a big funnel and the rad when i refilled it. this way, the coolant level was always the highest point and the bubbled would come up and out into the funnel and be replaced with coolant at the same time.
"they" sell kits like this to make the job a little easier. but that is just what i did.
Since it runs at 190F though, i might just leave it alone till the coolant needs to be replaced. (3 - 5 years or something like that)
the 4runner ran at 200F without fault.
a little over a year later when i re-replaced my t-stat while i added good antifreeze, i simply reinstalled the new one just as the old one came out (up).
i used a slightly cooler t-stat and the 4runner runs at 190F rock solid.
i am debating on going back in there to rotate it DOWNWARD after actually reading the proper procedure.
but more to the point, i used a 4 inch section of garden hose between a big funnel and the rad when i refilled it. this way, the coolant level was always the highest point and the bubbled would come up and out into the funnel and be replaced with coolant at the same time.
"they" sell kits like this to make the job a little easier. but that is just what i did.
Since it runs at 190F though, i might just leave it alone till the coolant needs to be replaced. (3 - 5 years or something like that)
DK327
Member
Get an OEM thermostat and put the jiggle valve @ 6pm and be done with it. Do it proper!
pluton
Senior Member
Since I've owned my '97(2013), I've replaced the radiator once and exchanged the coolant once after that. Both times I opened the heater to full hot before draining, and left it open during and after refill, until I drove the car and confirmed there were no problems. And there were no problems: No air pockets causing overheating, no need to burp the system, no need to refill on an incline. I report, you decide.