I have a 93 Camry 3.0 V-6 with over 192k. GREAT CAR that I plan on going to 250k. One problem. It has a hydraulic motor radiator fan assembly and the fan runs all the time at a very high rpm and sounds much like a small jet engine. There isn't any difference between when the car is cold and idling or when it is warm and running. This problem started at around 175k. Is there a fix aside from replacing the complete motor and fan assembly, $$$$!!!! Or does anyone have a salvaged one that they want taken off their hands.
93 V-6 hydraulic radiator fan
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Go here...http://oregonstate.edu/~tongt/camry/index.html
Download the manual. It's aa PDF so use search for fan. It will lead you to the section on the hydraulic cooling fan. Should be some useful info in there.
FWIW
YMMV
Download the manual. It's aa PDF so use search for fan. It will lead you to the section on the hydraulic cooling fan. Should be some useful info in there.
FWIW
YMMV
Download the Gen_3, 1MZ-FE (V6) engine section, info starts about page 345.
The fan system has various sensors for coolant temp and A/C overpressure. The fan is controlled by a solenoid valve. One of these items could be defective resulting in the fan operating all the time. The system may be designed to run continuously if s a component fails.
The fan system has various sensors for coolant temp and A/C overpressure. The fan is controlled by a solenoid valve. One of these items could be defective resulting in the fan operating all the time. The system may be designed to run continuously if s a component fails.
it's not likely the hydraulic motor itself since it just responds to the pressure it is fed and turns. I think it's pretty reliable.
Check the coolant temp sensor and its wiring harness for this which is mounted on the water inlet housing down near the thermostat on this engine. (A bitch to get to)
As well, you may want to locate the solenoid near the power steering pump and disconnect it temporarily to see if it stops the fan. If it doesn't, it's probably stuck open. If it does, then you will need to trace back to the Fan ECU and its inputs to see what is going on.
The best manual for you is the 1993 Lexus ES300 which describes the hydraulic fan stuff in intricate detail. See the 'Engine.pdf', specifically the '62coolantc.pdf' subsection starting on pg. 265.
cheers,
dave mc
Check the coolant temp sensor and its wiring harness for this which is mounted on the water inlet housing down near the thermostat on this engine. (A bitch to get to)
As well, you may want to locate the solenoid near the power steering pump and disconnect it temporarily to see if it stops the fan. If it doesn't, it's probably stuck open. If it does, then you will need to trace back to the Fan ECU and its inputs to see what is going on.
The best manual for you is the 1993 Lexus ES300 which describes the hydraulic fan stuff in intricate detail. See the 'Engine.pdf', specifically the '62coolantc.pdf' subsection starting on pg. 265.
cheers,
dave mc
My .02
The fan ECU is actually pretty easy to get to... a phillips screw driver and a 10mm socket and you can pull the glove box out and get right to the ECU (it's a small box the size of a pack of cigarettes on the right side of the hole for the glove box once you get it out).
The PDFs should include some wiring information about the ECU, and you can check voltages directly while it's running to see what's sending signals and what the ECU is sending in response. A volt meter across the blue/white and blue/yellow wires on the wire harness showed me that I was getting VERY consistent water temp (about 2V) regardless of driving conditions, so the cooling system is doing its job. Checking the ECU output to the solenoid (I think it's the yellow and yellow/blue wires), I saw it started out a 0V, but then started turning on the fan at idle with about 4V. After driving for awhile, it would start kicking up to 7 or 8V and it sounded like a jet.
The ECU takes signal in from the water temperature, the A/C overpressure switch, and a line in from another ECU. I jumpered the A/C overpressure switch so it was consistent, and the car's fan acted a lot more normal... it still varied (which indicates that the other ECU's signal must vary with engine conditions), but it didn't sound quite like the Harrier it resembled before. I am wondering now if this switch needs to be replaced...
From a troubleshooting perspective, the more you can dig into it for first-hand data (volts and such) the clearer the answers become.
Good luck!
The fan ECU is actually pretty easy to get to... a phillips screw driver and a 10mm socket and you can pull the glove box out and get right to the ECU (it's a small box the size of a pack of cigarettes on the right side of the hole for the glove box once you get it out).
The PDFs should include some wiring information about the ECU, and you can check voltages directly while it's running to see what's sending signals and what the ECU is sending in response. A volt meter across the blue/white and blue/yellow wires on the wire harness showed me that I was getting VERY consistent water temp (about 2V) regardless of driving conditions, so the cooling system is doing its job. Checking the ECU output to the solenoid (I think it's the yellow and yellow/blue wires), I saw it started out a 0V, but then started turning on the fan at idle with about 4V. After driving for awhile, it would start kicking up to 7 or 8V and it sounded like a jet.
The ECU takes signal in from the water temperature, the A/C overpressure switch, and a line in from another ECU. I jumpered the A/C overpressure switch so it was consistent, and the car's fan acted a lot more normal... it still varied (which indicates that the other ECU's signal must vary with engine conditions), but it didn't sound quite like the Harrier it resembled before. I am wondering now if this switch needs to be replaced...
From a troubleshooting perspective, the more you can dig into it for first-hand data (volts and such) the clearer the answers become.
Good luck!
Those PDF's are for a 1mz, do the 1mz's use hydrualic fans too?
Yea my car is almost done lol to many problems, but definatly an awsome car!!!!92ES5sp said:
Did you ever find out what causes the roaring sound from the fan? Mine does this periodically, and when it does roar, I can feel a slight load put on the engine. Any clues?
Do you know where i could find the manual you mentioned in youre post regarding the hydraulic cooling fan system?
I coulnt get the link you had on youre post to work. I could really use the information my car is overheating and ive done several things but the fan still isnt working properly. Any help would be most appreciated.
I coulnt get the link you had on youre post to work. I could really use the information my car is overheating and ive done several things but the fan still isnt working properly. Any help would be most appreciated.
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Links to the factory service manual are not allowed.
What, exactly, is your fan system doing? If the fans aren't coming on as soon as they should, or running fast enough, there are only a few components that control that. There's a fan computer control, separate from the ECU. It's located near the ECU behind the glove box. There's a thermister that monitors coolant temperature that the fan controller monitors. It's located in the water pump housing; follow the lower radiator hose back to the engine. You'll find that sensor in the housing where the radiator hose attaches.
Thanks BMR for helping. It has the hydraulic radiator fan system and the fan from the time you start the engine runs super slow and never increases in speed. Ive replaced the solinoid valve on the power steering pump and that did nothing. Ive tried to check the wiring at the cooling fan ecu but not for sure exactly what im suppost to be checking. If i drive it on hwy. for a short time the gauge stays at normal operating temp. but as soon as i exit the hwy and start doing stops and starts a lot the gauge will go clear past the red on the gauge. Open the hood to find antifreeze all over the engine due to the overflow bottle cap popping off. Too much presure i assume. Meanwhile the fan is still in its same slow mode. If i put the fan in the open loop mode using a jumper wire at the diagnostic port under the hood the fan runs wide open and i mean very fast and loud so that makes me think that their cant be any blockages in the ps system or it wouldnt work in the open loop mode. Help please and thank you.
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Here's a diagram of the hydraulic system which might help. I forgot there's also a solenoid valve that controls fluid flow to the fan. That can be faulty, but I see you've already replaced that, so hopefully it's safe to assume it's good.
Here's a few things I found in the FSM that you can check:
In the diagnostic port under the hood on the passenger side, jumper terminals OP1 & E1 to force the fans to run at 1,100 RPM.
Disconnect the hydraulic line to the fan and connect a pressure gauge to the line. Oil pressure should be 981-1,961 kPa at idle (750 RPM) with the jumper installed.
ECT sensor resistance should be 1.48-1.58 ohms at 80 degrees C (176 F). Note for others: This is NOT the same ECT monitored by the main ECU to control engine operation.
Solenoid valve resistance should be 7.6-8.0 ohms at 25 degrees C (77 F)
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Here's a few things I found in the FSM that you can check:
In the diagnostic port under the hood on the passenger side, jumper terminals OP1 & E1 to force the fans to run at 1,100 RPM.
Disconnect the hydraulic line to the fan and connect a pressure gauge to the line. Oil pressure should be 981-1,961 kPa at idle (750 RPM) with the jumper installed.
ECT sensor resistance should be 1.48-1.58 ohms at 80 degrees C (176 F). Note for others: This is NOT the same ECT monitored by the main ECU to control engine operation.
Solenoid valve resistance should be 7.6-8.0 ohms at 25 degrees C (77 F)
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