Bleeding Coolant - 95 Camry

I put a new radiator in my 95 Camry 4 cylinder and had a hard time getting the air out of the system. After a couple of test drives I finally got a big burp that splashed coolant out of the radiator and then it was okay but there must be a better way.

Since I put in the new radiator the fans don't come on by themselves. I pulled the plug at the left top so that they stay on all the time but I need to figure out what's going on. A broken wire should keep the fans running so it could be a short in the wires. I suppose I need to test the temp sender for connectivity as well but I'd be surprised if it failed closed. Any other suggestions?

Mitch

Reply to
Mitch
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Were they running before, was your radiator clogged overheating the motor making the fan run unnesisarily, Is it cold where you are, My fan doesnt run in winter hardly ever. Is your thermostat bad, it will keep engine temp and milage lower, so a new radiator cooling better will make them not run.

Reply to
ransley

The only time that my fans kick on (and I can see/hear them on) when I let the car sit for a long time (about 15 minutes) on idle in a heated garage. I don't know where you're located, but if it's cold out where you're at, then you might not see the fans kick on for a while. You might just pull the accelerator wire while you stand watching the fans for a couple of minutes and see if they kick on. Just a thought.

Reply to
Joe

The fans work. If you pull the connector plug to the sensor at the top of the radiator the fans will run whenever the car is on. They only stopped coming on automatically after I replaced the radiator.

The 1.5 year old radiator developed a 6" crack across the top. It had a lifetime warranty but it's still a pain to change it. And to think I paid extra for a premium radiator!

Mitch

Reply to
Mitch

You have to get the engine warm enough for the thermostat to open. Then some air trapped in the engine block will get "burped" out. There are different ways:

  1. Run at normal idle and wait until the upper radiator hose (outlet) is warm. This tells you that the thermostat has opened. Then immediately shut off. This helps prevent damage to the engine because of air pockets in a just-refilled system. US domestics typically recommend this method.

  1. For simpler cooling systems where the radiator cap is at the highest point like the Camry, air pockets are less of a problem. Then you can run the engine at fast idle, 1500-2000 RPM until the radiator fan comes on once or twice. If the coolant level drops during the time just add as you go. Then shut off and wait for the engine to cool. Fill up if still needed.

  • Use the specified capacity and drained amount as a guide to know how much more you have to add. Also you'll know how much more coolant you still need.

Reply to
johngdole

You probably don't want to be "test driving" an aluminum engine to burp. Also, change out the radiator cap with a new one that has a spring loaded vacuum return valve. Not the cheap Denso hang-loose plastic valve. That way you'll have less air in the system as it stabilizes. Check the Stant brand in your local parts store.

The 4 cyl should use the 0.9 cap or 13psi. I think 0.9 on the cap means 90% of 1 ATM (atmosphere)?

Reply to
johngdole

What is outside temp, your new radiator might be a good one cooling better, there should be an air bleed somewhere to remove excess air. Also to much antifreeze will make a car motor run Hotter kicking in your fans. 100% antifreeze will not cool as well as a 50-50 mix, water transfers heat the best but pure water will corrode the system and have no boil over or freeze protection

Reply to
ransley

Basically I used method 1 with the addition of squeezing the lower hose several times after the thermostat opened. When I thought I was done I took it for a test drive and found that the temperature was going too high and the heater was blowing cold so I did it again with the same results. The third time I finally got a big burp. I thought there must be a better way. FWIW I didn't have this problem the previous time that I changed the radiator so I don't know why it was difficult this time.

Oh yeah, the radiator fan wasn't coming on at all but I think I may have shorted the wires to the sensor while struggling with the plug.

Mitch

Reply to
Mitch

Maybe its just working right now as you said with air it overheated/

Reply to
ransley

Sounds like the problem is simply that the remaining air in the coolant boiled out, and it created an air pocket causing the engine to overheat. When the coolant finally got hot enough with repeated test drives, the air got boiled out (like you boil water) and it "burped".

Basically what you did during test drive was method 2. So after warming the engine up and you filled to within 8oz of full capacity with method 1, allow the engine to cool, then run it til the fan comes on to boil out the air. That should help.

Also, your cooling fan is working, as it runs when you disconnect the ECT connector. Just make sure that the ECT sensor (bottom of the radiator, which you transferred I assume? Or new?) should show no continuity above 199degF as described the Autozone's free guide for

3/5S-FE engines:

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Basically I used method 1 with the addition of squeezing the lower hose

Reply to
johngdole

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