Oil Cooler Fan Question
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Oil Cooler Fan Question
I know this topic has been discussed at length but being technically incompetent, and not knowing how to perform the wiring bypass test, here's my question:
When my car is stationary and oil temp reaches 9:30 level, the oil cooler fan comes on (i think it's on high because it feels the same as the a/c blower) for about 10secs, and then goes off completely. Fan comes on again after 5mins for 10secs and off. This 10sec on, 5min off cycle repeats itself when oil temp level is at 9:30. I can never seem to feel the slow speed fan.
When my mechanic plugs the Bosch hammer tool into the centre console, it shows no fault or errors.
So is my oil cooler resistor faulty or not? If it is, shouldn't the fault show up on the Bosch hammer?
When my car is stationary and oil temp reaches 9:30 level, the oil cooler fan comes on (i think it's on high because it feels the same as the a/c blower) for about 10secs, and then goes off completely. Fan comes on again after 5mins for 10secs and off. This 10sec on, 5min off cycle repeats itself when oil temp level is at 9:30. I can never seem to feel the slow speed fan.
When my mechanic plugs the Bosch hammer tool into the centre console, it shows no fault or errors.
So is my oil cooler resistor faulty or not? If it is, shouldn't the fault show up on the Bosch hammer?
#2
I'm not an expert, but I doubt a faulty fan resistor will show up on a hammer. It's probably just a temperature triggered circuit. When the temp gets high, the fans goes on. When it gets low, the fan goes off.
Follow the procedures for diagnosing your high speed fan and then install the oil cooler fan switch. Or even better, install a turbo s oil cooler or cargraphics oil cooler.
Follow the procedures for diagnosing your high speed fan and then install the oil cooler fan switch. Or even better, install a turbo s oil cooler or cargraphics oil cooler.
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My oil cooler fan would not come on at all.
I pulled the relay and did the relay bypass p-car test and the fan would not come on at all slow speed or fast speed.
The dealer said the resister is the most common part they replace so I tried it.
When I pulled the old one out it was in three pieces.
I replaced it and tried the relay test again and sure enough I could manually get the fan to run in slow and fast speed.
Now as soon as the temp gauge shows 9pm the fan kicks on and stays on until the temp drops.
Steve
I pulled the relay and did the relay bypass p-car test and the fan would not come on at all slow speed or fast speed.
The dealer said the resister is the most common part they replace so I tried it.
When I pulled the old one out it was in three pieces.
I replaced it and tried the relay test again and sure enough I could manually get the fan to run in slow and fast speed.
Now as soon as the temp gauge shows 9pm the fan kicks on and stays on until the temp drops.
Steve
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I got two of the switches at Hershey this past Sat. for a total of $11. Now I have a spare! DIY install will probably be before my May 22nd DE and I'll post a full report.
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993C4,
1) The A/C fan runs continuously on low speed anytime the A/C is on. The "breeze" you're feeling from the A/C fan is the fan's low speed.
2) The oil cooler fan turns on to low speed at about the 9:30 position that you speak of. That is normal. It is also normal for the oil cooler fan to cycle on and off like you describe.
It looks like your oil cooler system is functioning normally. You may, as a precaution, want to change the oil cooler and A/C fan relays and ballast resistors sometime. They are high mortality parts.
1) The A/C fan runs continuously on low speed anytime the A/C is on. The "breeze" you're feeling from the A/C fan is the fan's low speed.
2) The oil cooler fan turns on to low speed at about the 9:30 position that you speak of. That is normal. It is also normal for the oil cooler fan to cycle on and off like you describe.
It looks like your oil cooler system is functioning normally. You may, as a precaution, want to change the oil cooler and A/C fan relays and ballast resistors sometime. They are high mortality parts.
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Re: Oil Cooler Fan Question
Originally posted by 993C4
I know this topic has been discussed at length but being technically incompetent, and not knowing how to perform the wiring bypass test, here's my question:
I know this topic has been discussed at length but being technically incompetent, and not knowing how to perform the wiring bypass test, here's my question:
I had the same fan cycling as you did. When I disconnected the plug, the fan went on high speed. It turned out that my resistor was bad. I had both resistors replaced while the bumper cover was off just for insurance. The new part is a lot more durable looking than the old one.
BTW, I also now have an override fan switch - highly recommended of you autocross or track your car, as it makes a substantial difference in the oil temps. Directions on Robin's site also.
Last edited by Pete Lech; 04-29-2004 at 01:09 AM.
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Skip, I might get to it this Sat., if the lady lets me out of the house. I have to use up some of my car credits with her to go to the Deutsche Marque concourse show in Sunday. I also want to install my RS heater bypass tube this weekend, since cold weather is leaving us. Hell, I may just drive to the Metro parking garage to do it in seclusion.
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Re: Re: Oil Cooler Fan Question
Originally posted by Pete Lech
...BTW, I also now have an override fan switch - highly recommended of you autocross or track your car, as it makes a substantial difference in the oil temps. Directiosn on Robin's site also.
...BTW, I also now have an override fan switch - highly recommended of you autocross or track your car, as it makes a substantial difference in the oil temps. Directiosn on Robin's site also.
Edward
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Rick and others,
I actually went ahead and did the oil cooler fan override switch tonight. It took about 1.5 hours and I am slow (keeping with my HWFMR team membership) with this stuff - it wasn't hard at all, just a little time consuming.
I have the 944 switch on order for the center console, so I just used a cheap Radio Shack flip switch for the time being. Once the switch is turned on, the fan takes about 15-30 seconds to actually start, but will turn off in just 5 seconds or so.
I'll report back soon, when I have had to sit in traffic and the heat.
-Skip
I actually went ahead and did the oil cooler fan override switch tonight. It took about 1.5 hours and I am slow (keeping with my HWFMR team membership) with this stuff - it wasn't hard at all, just a little time consuming.
I have the 944 switch on order for the center console, so I just used a cheap Radio Shack flip switch for the time being. Once the switch is turned on, the fan takes about 15-30 seconds to actually start, but will turn off in just 5 seconds or so.
I'll report back soon, when I have had to sit in traffic and the heat.
-Skip
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Originally posted by swftiii
Rick and others,
... Once the switch is turned on, the fan takes about 15-30 seconds to actually start, but will turn off in just 5 seconds or so...
-Skip
Rick and others,
... Once the switch is turned on, the fan takes about 15-30 seconds to actually start, but will turn off in just 5 seconds or so...
-Skip
I used a second fog light switch from Gert in the blank spot on the dash. Now if I could get it to illuminate when it is in override mode, it would be almost perfect: Normal position is pulled out, pushed in to turn on the cooler fan.
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993C4,
I agree with Pete, sounds to me like your resistor is toast, and you're getting momentary cycling of the fan in fast-speed. If the slow-speed fan is operable, it will run for several minutes, and you can actually see the oil temperature drop below 9:00 before it turns off. If your fan isn't running long enough to actually cool the oil, something is amiss.
This momentary cycling is similar to what people see when the A/C condenser fan ballast resistor fails, and the fan cycles in fast-speed, as the slow-speed fan isn't running continuously like it should.
You won't have high confidence the resistor is bad (or good) until you perform the jumper test.
I do believe the Bosch Hammer is supposed to be able to identify a faulty resistor. I don't have my shop manual here with me, but--if nothing else--I'm pretty sure the hammer can be used to turn the fan on and off. If someone has their shop manual handy, they should be able to find what the hammer can/cannot do in the trouble-shooting section.
Pete....Yup, there may be a delay, after flicking your switch, before the fan starts running in fast-speed. I think it takes a short while for the CCU to recognize that there's an open circuit, then switch into its default mode (fast-speed).
I agree with Pete, sounds to me like your resistor is toast, and you're getting momentary cycling of the fan in fast-speed. If the slow-speed fan is operable, it will run for several minutes, and you can actually see the oil temperature drop below 9:00 before it turns off. If your fan isn't running long enough to actually cool the oil, something is amiss.
This momentary cycling is similar to what people see when the A/C condenser fan ballast resistor fails, and the fan cycles in fast-speed, as the slow-speed fan isn't running continuously like it should.
You won't have high confidence the resistor is bad (or good) until you perform the jumper test.
I do believe the Bosch Hammer is supposed to be able to identify a faulty resistor. I don't have my shop manual here with me, but--if nothing else--I'm pretty sure the hammer can be used to turn the fan on and off. If someone has their shop manual handy, they should be able to find what the hammer can/cannot do in the trouble-shooting section.
Pete....Yup, there may be a delay, after flicking your switch, before the fan starts running in fast-speed. I think it takes a short while for the CCU to recognize that there's an open circuit, then switch into its default mode (fast-speed).
Last edited by Randall G.; 04-29-2004 at 09:29 AM.
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Rick,
Which switch are you going to use (rear fog lights, 944 hazards, or radio shack special)?
I'm going to use the 944 hazard switch for the center console. Since I know the setup works and I have a radio shack $1 switch working, when the 944 switch comes, I'm going to see if I can figure out a way to replace the triangle with a fan symbol. That should be fun to figure out and make the install really look OEM.
The directions on Robin's site are perfect and exact with regard to which wire to cut from the back of the CCU and everything. It worked just as documented.
Good luck,
-Skip
Which switch are you going to use (rear fog lights, 944 hazards, or radio shack special)?
I'm going to use the 944 hazard switch for the center console. Since I know the setup works and I have a radio shack $1 switch working, when the 944 switch comes, I'm going to see if I can figure out a way to replace the triangle with a fan symbol. That should be fun to figure out and make the install really look OEM.
The directions on Robin's site are perfect and exact with regard to which wire to cut from the back of the CCU and everything. It worked just as documented.
Good luck,
-Skip
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This may be a stupid question, but why install a switch? If the resistors are working properly, shouldn't it keep the oil at the correct operating temperature?