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My dilemma is as follows:
My car starts and runs just fine….unless I am idling with the A/C on.
If I find myself sitting and idling with the A/C on for as few as five minutes it kills the battery.
It starts running a little weakly and if I kill the engine it won’t start again until I get a boost.
I can run at highway speeds for hours at a time with the A/C on with no issues whatsoever.
Another thing that started happening about the same time is my coolant will boil/pressure out causing the engine to overheat eventually.
When I park I will find a pool of coolant on the ground from the overpressure hose from the radiator cap.
Both fans come on when I turn on the A/C and I think they come on otherwise as needed.
I spun both fans by hand but one spins more freely than the other.
It isn’t locked up or anything it just spins with a slight bit more resistance.
Things I’ve done so far:
I took out the coolant temp sensor that goes to the fans and cleaned it and the threads in the thermostat housing with a brass wire brush.
I’ve only driven it around town since then with no issues.
I have filled the cooling system and bled out the air.
Could my alternator be going bad or maybe my fans are on the way out?
How should I test the fans?
I have a multimeter and am comfortable using it.
Should the resistance in the fans be zero or something else?
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Replies
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I believe you are dealing with two separate issues.
First the electrical system.
Ensure your belt is on tight and is not slipping in any way.
You could have a weak battery or weak alternator.
Check the battery charge with the vehicle off. If it is less than 12.6, start the car with all accessories off and run it to 2000 rpms for 10 minutes or so and re-check. It should be above 12.6.
To check the alternator, Start the vehicle and run to 2000 rpms. Check the voltage, it should be 14.5 to 15.4
Then turn on accessories (A/C, Fan fully on, lights on) and with the vehicle at 2000 rpms, check the voltage, it should be around 13.2 to 14.7.
If you are not getting these numbers, your alternator may be weak.
With the overheating situation. Visually inspect the radiator for damage and obstructions (leaves, crud, mud, bugs, broken fins). Check the cap, it may need replaced. Also, you may want to ensure the system is holding pressure with a pressure tester.
-Karl
Well, I’ve replaced the alternator with the higher output option that was available on this car and installed a new Diehard battery. I have had no starting issues since and I notice that the radiator fans really spin a lot faster now.
Yes but I am still losing coolant about every two months or so.
I think that I have a warped head or blown head gasket.
I drive this car hard for work and it still takes a couple months or so for it to get low.
It just blows it out the overfill tube because there is too much pressure for the cap.
Try replacing the cap. It could be weak. You need to verify
that the cooling fan cycles at temp. If you idle the car. do the
fan or fans ever cycle?I think your battery is bad as well as the radiator cap. I would have the battery load tested and the alternator output checked. You can’t do that with just a volt meter. When you’re idling with everything on you are in a way load testing the battery.
For the cost of a rad cap I would replace it before doing anything else to the cooling system.
Yes, the fans cycle at idle when at temp even when freezing outside. The temp needle stays in the middle for the most part. After a long pull on the road when I slow down to go through a drive thru I’ve noticed the needle move toward about 5/8 toward H but the fans kick on and cool it right down.
I bought a radiator cap once but it was the wrong one. I think maybe somebody either replaced the radiator at some point or I need the one that O’reilly thinks is for the manual transmission.
The one I got was too shallow to fit over the locking lips on the radiator.
I should definitely give that one a go again.
I had forgotten about that.
I replaced the alternator and battery because they both were showing weak under load(a/c on, rear window defroster, fans on high, headlights on high, etcetera.
I tried the to get a radiator cap but the one they gave me didn’t fit.
I’ll have to give that one another go.
[quote=”iamtheosprey” post=83885]I replaced the alternator and battery because they both were showing weak under load(a/c on, rear window defroster, fans on high, headlights on high, etcetera.
I tried the to get a radiator cap but the one they gave me didn’t fit.
I’ll have to give that one another go.[/quote]
If someone sells the stant brand. here is what you
need in a radiator cap.
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