2001 Cruiser Overheating after heater Tee broke/repaired

Joined
Nov 18, 2015
Messages
14
Location
Boulder City, NV
Hi all. My '01 LC (281k) is overheating after the heater tee blew. Temp never got into the red that I saw. I replaced the tee and filled the coolant system. At idle, no overheating problems but I am getting misfire codes on cylinders 2,4&6. When I drive, the temp climbs quickly a few minutes in so I've pulled over and let it cool down then drove back home. The upper radiator hose is under a ton of pressure like it isn't circulating coolant. I replaced the thermostat and nothing changed. Water pump and radiator were replaced by toyota along with the timing belt etc last summer. Idle temp is between 176 and 184. No white smoke from exhaust. No milky oil or pressure coming from oil filler tube at idle. Any advice other than a compression check to see if a head gasket blew? Thanks for your time.
 
Joined
Oct 13, 2018
Messages
90
Location
na
This might be silly but after you did the coolant work did you burp the system so there was no air left?
 
Joined
Nov 18, 2015
Messages
14
Location
Boulder City, NV
I was hoping that was the issue... The heater was blowing cold so I took it for a drive to burp it and that was when the temp climbed the first time. I idled it on a steep incline in my driveway and the heater is blowing hot now but its still heating up when I get out on the road. The reservoir and radiator are topped up. That upper radiator hose is ROCK hard at operating temp.
 
Joined
Oct 13, 2018
Messages
90
Location
na
I was hoping that was the issue... The heater was blowing cold so I took it for a drive to burp it and that was when the temp climbed the first time. I idled it on a steep incline in my driveway and the heater is blowing hot now but its still heating up when I get out on the road. The reservoir and radiator are topped up. That upper radiator hose is ROCK hard at operating temp.
I’ve seen some guys get a funnel system, run the radiator cap open with coolant in the funnel and have the front end of the car on an incline. That’s what I was thinking about when I mentioned burping. But maybe your method works.
 
Joined
Jul 21, 2019
Messages
779
Location
Arizona
Could be exhaust gases leaking into system (hg leak). Have you removed the radiator cap (when cool) and watched for bubbling (at idle) before the thermostat opens? You can rent a tester at most parts stores - if the fluid in the tester turns yellow, then you have blown hg that’s allowing exhaust gasses into cooling system.

Potential other culprits: radiator cap is bad (when was last replaced?), or thermostat is bad/installed wrong (did you make sure jiggle valve was in correct orientation?).
 
Joined
Nov 18, 2015
Messages
14
Location
Boulder City, NV
Could be exhaust gases leaking into system (hg leak). Have you removed the radiator cap (when cool) and watched for bubbling (at idle) before the thermostat opens? You can rent a tester at most parts stores - if the fluid in the tester turns yellow, then you have blown hg that’s allowing exhaust gasses into cooling system.

Potential other culprits: radiator cap is bad (when was last replaced?), or thermostat is bad/installed wrong (did you make sure jiggle valve was in correct orientation?).
I didn't check the jiggle valve orientation before I put it in. I didn't know those could/would be wrong from the factory. I'll check it. Radiator cap got replaced with the radiator about a year ago. I'll check for bubbles at idle tomorrow when its totally cooled off. Thanks for the suggestions!
 
Joined
Jul 21, 2019
Messages
779
Location
Arizona
I didn't check the jiggle valve orientation before I put it in. I didn't know those could/would be wrong from the factory. I'll check it. Radiator cap got replaced with the radiator about a year ago. I'll check for bubbles at idle tomorrow when its totally cooled off. Thanks for the suggestions!
Yes, jiggle valve should be at 12 o’clock, though anywhere between 11 and 1 o’clock should be ok too (per the FSM). Also make sure you have the correct OEM thermostat - it should be rated for 180*F.

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Are you getting any codes aside from the bank 2 misfires?
 
Joined
Nov 18, 2015
Messages
14
Location
Boulder City, NV
Thanks for the diagram. That makes sense. I thought the suggestion was that the little jiggly thing was in the thermostat backward (wrong orientation) which seemed super unlikely. There's exactly a 1 in 6 chance that I put that in the correct way because I paid no attention at all. I'll check it. New thermostat is 180 deg. I did get the p300? telling me that I had multiple misfires but other than that just bank 2 misfire codes.
 
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