Mechanics

TOYOTA AVALON THERMOSTAT PROBLEM

1996 Toyota Avalon • 160,000 miles

I believe I have an air pocket in my cooling system. After a 1/2 hour highway drive then at idle the temp gauge goes up to 3/4 from the regular 1/2. I was told it was an air pocket that has to be bled from the cooling system. From looking online I see that Honda's have a beeder but not Toyotas. My engine is the Toyota 1MZ-FE 6-cyl 3.0. I was thinking of getting that special yellow funnel kit that attaches to the radiator neck to get all the air out, will this help? I have sqeezed the upper hose to remove bubbles too. I was thinking I could remove the temp sensor above the thermostat to allow air to bleed out. Should I do this? I have driven over 200 miles with this problem but it hasn't gone away. Please help.
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PCMentor29
November 21, 2012.



I remove the rad and send it out to be acid flushed

Roy

ASEMaster6371
Nov 21, 2012.
Yes I will have it flushed. Can they test it for blockages before it is removed from car? After?

Here's their answer: Dear Pete; There is no chemical that will help any blockage, except for water. I would suggest you remove some of the Fiberlock mixture by opening and draining it out of your block or siphoning. You can then refill will only water to dilute it. That should free any blockages.
Sincerely,

CRC Technical Support

Thanks, Pete

Tiny
PCMentor29
Nov 21, 2012.
I will forward this to our boss

Roy

ASEMaster6371
Nov 21, 2012.
The radiator shop said they can't wash plastic/aluminum radiators. For a new one at AutoZone is $115. I will get it and install it and test it today. I will post the results later.
Also I checked the temps: at idle, Gauge at medium, the upper hose got hot 160 F while the lower stayed at 100F(car was not totally cooled down) The thermostat housing stayed around 140F but the inlet housing(where the Rad cap goes on opposite side of engine) was 182F(thermostat is a 180F in service manual) I did rpm 2500 for a minute and the lower hose got warm. I am using this info to OK the new radiator.
Thanks, Pete

Tiny
PCMentor29
Nov 21, 2012.
Ok I put in the new radiator but am letting the engine cool down for a couple hours so I can add more coolant mix. I checked the temperatures and am a little confused. After driving 2 miles 750-3500 rpm the upper is 170F the lower is 140F the TS housing is 170F and the inlet housing is 190F. Could these be bad values, meaning a bad thermostat? Or are they normal? I take the avg of 3 measurments each time. I think the coolant flows from the engine to the upper hose through the radiator then the lower hose to the thermostat is this correct.

I am going to buy a thermostat, gasket, and O-ring just in case. How is it possible though for that stopleak stuff to make a thermostat not open correctly when the thermostat had been working fine? Is there an answer? I may be jumping the gun a little I will top off and test drive again. By the way this engine doesn't have the radiator cap on the radiator. I really don't know if I am skilled enough to change the Thermostat in this car. I have done it in my 1996 Ford Ranger and my 1996 Ford Aspire with competence. I pulled a junkyard thermostat housing off another Avalon and it seemed complicated.

Thanks, Pete

Tiny
PCMentor29
Nov 21, 2012.
Temps sound good.

Roy

ASEMaster6371
Nov 21, 2012.
"Temps sound good" that's promising. I can wait to buy the thermostat until I top off and testdrive. As I was reading my e-manuals I realized that the "jiggle valve" on top of the thermostat could very well get clogged by the stopleak I used. Let's see how it goes.

FYI Mike from 2carpros sent me this message: The donation upgrade option is available below the initial question. We will be fixing it so you can donate at any time. We really appreciate your donation. Thanks, Mike

Thanks

Tiny
PCMentor29
Nov 21, 2012.
I just road tested, mini torture test(same as before), and the temp on the gauge moved less than 1/2 a gradation throughout various driving and idling tests. It started at a point 1/2 a graduation less than middle once warmed up.

So the radiator was restricted. Thanks for your help.

The temps I recorded now fixed are Upper 162F, Lower 148F, Inlet 175F, and TS Housing 175F.

Thanks for your help. I will donate some more when they allow the feature. Pete

Tiny
PCMentor29
Nov 22, 2012.
Happy Thanksgiving Day

Rasmataz
Nov 23, 2012.
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