2003 camry 2.4
This is what is happening, cooling fans will not come on except when the AC is turned on and they will go off when the AC is turned off, otherwise the car will over heat.

This is what I have done...Replaced the fans (because the radiator fan was bad, after hooking them up to directly to the battery). I checked all the grounds, including the one under the intake, checked the fuses, checked relays when 12vots to the relay and used a ohm meter to see if it made contact when activated. on the three fan relays. Replaced and tested the new radiator sensor with a pot of water on the cooking stove and temp gauge and ohm meter. Unplug the radiator sensor while the car is running, the fans will come on, but go off as soon as it is plug back in. Replaced the thermostat.

what can I do next, before I burn the motor up trying to fix it?

 

I now have a mis fire code for number three

 

Did the car actually overheat?

 

When I first start it up it runs good, three different times I test drove it about a mile down the road, the engine started running rough as the temperature gauge on the dash was reaching mid-way. I turned the car around and started back home. As I am driving back into the garage, the motor was sounding badly and the gauge was mid way now. After cooling down, I check fluids to make sure the head did not warp. When the motor is running, taking the oil filler cap off, there is a lot of blow-by coming out. I am not sure if this is normal for Camry's. The motor may be miss-firing, showing a 303 code, since I took the intake off to get to the ground wire. I will check the no. three coil today..
A little history on this car, I bought the car with a broken timing chain from a mechanic. They had stripped out the inside of the cylinder head bolts, where they try to remove them. The threads on the bolts were ok. I removed the head and had it machined and the bent valves replaced. I put in the steel inserts after reading about the problems the 2.4 has with head bolts stripping out. (you know a oz of prevention, since I had the head off) Got a gasket set and put the timing chain on, making sure I had all the correct marks lined up. I believe this is where the mechanic made their mistake, lining up the chain on the wrong mark of the cam, because their are two marks on it.

 

Coolant Temperature Sensor is what is name is, located on the drivers side of the cylinder head

 

Thanks for the history on the car, you have taken some really good precautions and know about the engines weaknesses.
I'm hoping you didn't blow the headgasket. You might want to try a compression test before getting too carried away.

 

A normal operating engine does not need the fans running to keep the engine temp down when driving at speeds over say 10 mph. The fans working is not relevant unless in stop and go driving.

Suggest a block test to check for exhaust gases in then coolant. Might be able to rent a kit from a auto store. The internet sales them cheap enough.

Review the assy process to make sure there were not any rags, etc left in the coolant holes, ports, etc.

Is the T-stat working properly?

The trouble code could be related to the rough running which could be separate from the overheating problem.

 

I made sure no rags or paper towels were in the water jackets before the head was put on. I put in a new thermostat.

On start up, the engine sounds good, after two or three minutes, it starts making a rattling sound, with a little increase in rpm's it goes away and sounds good again. Almost like it is oil starved. It can be easily heard in the head and exhaust manifold when this happens.

No mix of fluids on the oil stick. I can run a compression test and let you know.

 

The VVTi controller can rattle at start up due lack of oil.

Plus the timing chain.

Post back with test findings.

 

the compression is as follows, the motor would start each time


no1-125

no2-135

no.3-125

no.4-125