engine coolant become hot quick but no heater!

chinesedawn · 02-13-2010, 11:05 PM

I change the radiator today,after I put the new one( actually not new one, it is a used one) in I did a test drive on the high way, but the coolant temperature goes high after 9 min about 60 miles/hour so I shut the car down and restart again, the Temperture drop to half and when I start drving it, Temperture goes high again and I DON'T have heater, I used to,I have heater before I change the radiator.

I touch the radiator, it's hot so it means the thermosta is good maybe... but the problem is the coolant in the raservior is cold....

cre · 02-13-2010, 11:45 PM

The reservoir being cool doesn't mean too much... it's in the coldest place under the hood with cold air blowing past it full time.

Are you losing coolant?

chinesedawn · 02-14-2010, 12:28 AM

Thanks, I didn't see any steam or leak, I will check the coolant level, I lose some coolant when I was disconnecting the lower radiator hose, maybe it is the problem.

supra.7mgte · 02-17-2010, 02:18 AM

make sure u got know air in the system... by the sounds of it u have air in it somewhere

DarkSupra2.5 · 02-17-2010, 03:52 AM

Your best bet to get rid of the air that's most likely in your system that I use, put your car in a driveway, or elevate the front of the car with ramps or jack stands, either way. open the radiator, turn the heater all the way up, start the car and fill the radiator. This allows the water to flow through the heater core and the water pump does the work for you in passing the air through the system.

The point is that you want the radiator fill point to be the highest point in the system so the air gathers there ya know? Good luck.

Krem · 02-22-2010, 05:07 PM

do you hear a gurgling/running water sound from behind the dash? could also sound like a squeeky hamster wheel gone awry... that's a good indication of air in the heater hose and thus air in your cooling system. However, given the fact the radiator was installed and the issues began at the same time, I'd have to guess you may have installed a clogged radiator. When it's cold, pop the radiator cap off, run the car... check to see if you see the coolant moving, indicating the coolant is moving thru.

Also, why did you replace the radiator? were you having issues with cooling before hand? maybe the issue didn't start with the radiator but could be a faulty water pump, thermostat or something more severe... hopefully you're not blowing smoke out of your tail pipe...

Finally, guess it could just be coincidence your heater's vacuum valve isn't working any more... preventing water from even flowing through your heater hose.

chinesedawn · 03-01-2010, 01:25 AM

I fixed the problem, the main reason is heater core is kind of clogged and coolant also a little low

02-13-2010, 11:05 PM	#1
chinesedawn Intake Join Date: Feb 2010 Location: laramie wy Posts: 35	engine coolant become hot quick but no heater! I change the radiator today,after I put the new one( actually not new one, it is a used one) in I did a test drive on the high way, but the coolant temperature goes high after 9 min about 60 miles/hour so I shut the car down and restart again, the Temperture drop to half and when I start drving it, Temperture goes high again and I DON'T have heater, I used to,I have heater before I change the radiator. I touch the radiator, it's hot so it means the thermosta is good maybe... but the problem is the coolant in the raservior is cold....

02-13-2010, 11:45 PM	#2
cre Toyota Racing Development Join Date: Apr 2007 Posts: 5,038	The reservoir being cool doesn't mean too much... it's in the coldest place under the hood with cold air blowing past it full time. Are you losing coolant? __________________ If something breaks or you need to contact a member of the administration please post HERE. Unless it's a private or administration matter please post it on the forum. It benefits no one else if car related questions aren't posted for future users and takes away from the time I'm able to spend helping on the rest of the forum. If you're so inclined I'm always more than happy to accept tips via PayPal. Tip Jar --->

02-17-2010, 03:52 AM	#5
DarkSupra2.5 3" Exhaust Join Date: May 2008 Location: Sacramento Posts: 60	Your best bet to get rid of the air that's most likely in your system that I use, put your car in a driveway, or elevate the front of the car with ramps or jack stands, either way. open the radiator, turn the heater all the way up, start the car and fill the radiator. This allows the water to flow through the heater core and the water pump does the work for you in passing the air through the system. The point is that you want the radiator fill point to be the highest point in the system so the air gathers there ya know? Good luck. __________________ 1jz-gte swap (Currently spun #3 rod bearings), Apexi high flow filter, Greddy thrust 3" downpipe, N1 3" catback with cat delete tube, 1 peice driveshaft, Bar and Plate intercooler, and 440 JDM 2jz injectors. Possible 2jz lower block swap in the works if I can't rebuild the 1j. So troublesome.

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02-14-2010, 12:28 AM	#3
chinesedawn Intake Join Date: Feb 2010 Location: laramie wy Posts: 35	Thanks, I didn't see any steam or leak, I will check the coolant level, I lose some coolant when I was disconnecting the lower radiator hose, maybe it is the problem.

02-17-2010, 02:18 AM	#4
supra.7mgte Intake Join Date: Feb 2010 Location: Alberta Posts: 36	make sure u got know air in the system... by the sounds of it u have air in it somewhere

02-22-2010, 05:07 PM	#6
Krem 3" Exhaust Join Date: Sep 2009 Location: Las Vegas Posts: 167	do you hear a gurgling/running water sound from behind the dash? could also sound like a squeeky hamster wheel gone awry... that's a good indication of air in the heater hose and thus air in your cooling system. However, given the fact the radiator was installed and the issues began at the same time, I'd have to guess you may have installed a clogged radiator. When it's cold, pop the radiator cap off, run the car... check to see if you see the coolant moving, indicating the coolant is moving thru. Also, why did you replace the radiator? were you having issues with cooling before hand? maybe the issue didn't start with the radiator but could be a faulty water pump, thermostat or something more severe... hopefully you're not blowing smoke out of your tail pipe... Finally, guess it could just be coincidence your heater's vacuum valve isn't working any more... preventing water from even flowing through your heater hose.

03-01-2010, 01:25 AM	#7
chinesedawn Intake Join Date: Feb 2010 Location: laramie wy Posts: 35	I fixed the problem, the main reason is heater core is kind of clogged and coolant also a little low