S
ssurfr2819
- Reaction score
- 21
- Thunderbird Year
- 2005
Parts Discussions in General Forums
I have read with interest the various threads on overheating and fan operation. My overheating symptoms started about two months ago. Since I hadn't observed any leaks or loss of coolant, and the thermostat was likely original, so I replaced the thermostat and associated housings. (Note the Gates CO34838 thermostat has a manufacturing deficiency. The fill cap above the thermostat leaks. Whether the throat of the plastic was too large or the cap o-ring was too small, I wasn't interested in learning. I ordered a replacement of the same product and it also leaked. So I ordered an AISIN THRFD0017 and moved along.)
After bleeding the system, I operated at idle while monitoring Engine Coolant Temperature. I was able to see the normal heating cycle, through thermostat open, and with heater on or off, the system performed normally. Upon turning on the AC, after a few minutes the temp started rising, and kept rising. During this time, I thought the fan did not sound like it was operating correctly. I also thought that the pull from the front grill seemed underwhelming. When it finally sounded like it was increasing speed, I didn't hear a full throated sound like I was accustomed to when the fan would usually kick in (e.g. stop and go traffic with AC on). It was more of a high whine sound. The temp went up to 230 and I turned off AC and shut down engine.
In a following test I clamped an ammeter to the fan supply line. It was stable around 7A at low, then eventually went to high about 18A when temperatures started rising, and when it appeared the cooling system was unable to keep up with the heat from the AC, it went to 37A. The ECT climbed to 230 so I didn't leave it on for long, but the 37A appeared not to be a transient, it was stable at that current.
I am waiting for a Powertrain Control and Emissions Diagnostic manual to arrive. I plan to test for other causes at that time. But in the meantime it seems that a 20 year old fan (66,000 miles with lots of Florida and Hawaii AC use) could be reaching end of life. I cannot find outlets with the Motorcraft 6W4Z‑8C607‑AA part or equivalents. There are a number of universal fans, but none seem to have a CFM that I have been advised is needed for the 2005 Tbird (2,500~). Has anyone recently replaced the cooling fan, and if so, what parts did you find available? I hate to buy a used fan because it will be 20 years old also. I am also open to other thoughts about my situation. The key for mine is that the coolant level is not falling, and the engine cooling process seems sufficient until the heat from AC is overwhelming the system. AFAIK the current 37A is not by design and should remain 18 or 20A for a good fan.
After bleeding the system, I operated at idle while monitoring Engine Coolant Temperature. I was able to see the normal heating cycle, through thermostat open, and with heater on or off, the system performed normally. Upon turning on the AC, after a few minutes the temp started rising, and kept rising. During this time, I thought the fan did not sound like it was operating correctly. I also thought that the pull from the front grill seemed underwhelming. When it finally sounded like it was increasing speed, I didn't hear a full throated sound like I was accustomed to when the fan would usually kick in (e.g. stop and go traffic with AC on). It was more of a high whine sound. The temp went up to 230 and I turned off AC and shut down engine.
In a following test I clamped an ammeter to the fan supply line. It was stable around 7A at low, then eventually went to high about 18A when temperatures started rising, and when it appeared the cooling system was unable to keep up with the heat from the AC, it went to 37A. The ECT climbed to 230 so I didn't leave it on for long, but the 37A appeared not to be a transient, it was stable at that current.
I am waiting for a Powertrain Control and Emissions Diagnostic manual to arrive. I plan to test for other causes at that time. But in the meantime it seems that a 20 year old fan (66,000 miles with lots of Florida and Hawaii AC use) could be reaching end of life. I cannot find outlets with the Motorcraft 6W4Z‑8C607‑AA part or equivalents. There are a number of universal fans, but none seem to have a CFM that I have been advised is needed for the 2005 Tbird (2,500~). Has anyone recently replaced the cooling fan, and if so, what parts did you find available? I hate to buy a used fan because it will be 20 years old also. I am also open to other thoughts about my situation. The key for mine is that the coolant level is not falling, and the engine cooling process seems sufficient until the heat from AC is overwhelming the system. AFAIK the current 37A is not by design and should remain 18 or 20A for a good fan.
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