2011 Ody EXL. Occasionally radiator fan keeps running for 5 mins even after ignition is off. No CEL, no codes so far. This issue never caused battery to drain. Where would i start to troubleshoot this?
Radiator fan running after ignition off
bb74
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What is the actual coolant temp?
You need a live data code reader for this.
You might be running on the hot side.
The fan can run when the ignition is off if the engine coolant is still too hot. This is normal behavior.
So, check coolant level etc. Maybe your Ody needs some cooling system attention. (thermostat, radiator fins, coolant level, etc)
Has your Ody been running hotter than normal?
If that fan runs when the engine is cool, there is another problem.
Buffalo4
PS:
So, check coolant level etc. Maybe your Ody needs some cooling system attention. (thermostat, radiator fins, coolant level, etc)
Has your Ody been running hotter than normal?
If that fan runs when the engine is cool, there is another problem.
Buffalo4
PS:
Joined
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9,369 Posts
PA is not Texas...
I recall reading something related to the AC system, that could cause the fan to run for extended periods.
is it both fans or just one?
as mentioned, get some data feeds on those engine coolant temperature sensors to rule that out.
I recall reading something related to the AC system, that could cause the fan to run for extended periods.
is it both fans or just one?
as mentioned, get some data feeds on those engine coolant temperature sensors to rule that out.
Is VCM still enabled? I believe a faulty muzzle device could cause this. It's something to remove from the system for troubleshooting purposes to at least rule out.
It's normal on a Honda for the fan to run with the engine off if the ECM sees a high engine temp. Look at your live data engine temps, you could have a failing temp sensor or a sticking thermostat causing the temp to be slightly higher. Have you done any recent cooling system work? Is the reserve tank and the radiator full? An air pocket that's settled near the temp sensor can cause this as well. Also a failed relay is common. See this thread. Removing the relay and testing for voltage on the control circuit would indicate if the ECM is seeing a hot condition or not.
Both fans stays on after engine is shut down. | Honda Odyssey Forum (odyclub.com)
I used to think the same, but 5min is not much. My TDI does this for 20min after an engine stop with both fans on high whenever it has a failed DPF regeneration. It only uses 1 battery that has a 100CCA higher rating battery than our Ody. Sometimes if it's doing a regen and I'm in town I've stopped 4-5 times and it ran for 20min, 4-5 times in a row but still started fine. Definitely something I try to avoid, if possible, though.
It's definitely something that needs fixed, but as long as they aren't making a bunch of little stops it shouldn't be an issue that kills the battery immediately or causes any battery longevity issues.
Thermostats are all designed to fail open. However, they can still fail closed or partly closed.
Thats what it measures when you've reached operating temperature? Was this measured with a thermal gun on the coolant itself or by the temp reading from the ECM via a scan tool?
I got the reading from the scan tool
Interesting that the fans are running that long after engine shut down then if it's not seeing an overheat condition. That is a low temp which leads me to believe your thermostat is actually failed open. Or it is an indication issue with the temp sensor and the ECM is just running the fans at full speed as a precaution. Do you have a thermal temp gun or thermometer? If it were me, the next thing I would verify is that the physical coolant is at or about that temp. After the engine has reached operating temp shut the engine off. Put a rag over the radiator cap and slowly press the cap down and turn the cap to relieve pressure. The cap will turn roughly 1/4 turn to the "pressure relief" detent where it may purge some coolant and pressure so be ready to press down and close the cap if need be or if the relief of pressure/coolant is happening too fast. Then turn the cap the rest of the way to remove the cap and take a temp reading of the actual coolant and let us know. 
This should help you see whether you have a bad temp sensor, a failed fan /or fuse or a failed thermostat.
This should help you see whether you have a bad temp sensor, a failed fan /or fuse or a failed thermostat.
107*C = 225*F. That's quite above the correct engine operating temp.
Thermostat opens around 165*F, and the 'highway' engine temp is generally in the 175*F range. The fans come on 'high' at 205*F or so. Engine temp should never get above ~210*F if everything is running normally (and it will almost always be below 200*F).
Sounds like there is a mechanical issue - clogged radiator, stuck thermostat, air bubble in coolant, head gasket failure, etc. Rare on a J35, but we don't know the whole history of the van.
-Charlie
Agree with all this.
If your temp really is 107*C, it sounds like the fans are working properly.
So you can stop troubleshooting the fans and should quickly try to figure out why it is running so hot.
Whoops. I read that as 107*F by assuming.
Agree with above
I don't think I ever changed my coolant and noticed the coolant levels were very low. I added Honda OEM coolant to the neck of the radiator and also to the reservoir upto mid mark of min and max levels. I'll monitor and see if this would solve the issue.
You should never need to add coolant, other than a tiny amount for evaporative loss from the overflow tank. So if you were low in both areas and don't know why, there is probably a problem somewhere.
But what you did is correct. Wait until cold, top up radiator and fill overflow tank to the high level. Better, and more likely needed if you were filling it from completely empty, would be to run the engine up to operating temp while the radiator cap is off, letting bubbles escape and keeping it topped up, with a funnel to catch splashes. But since you were not completely empty, and running for a while, skipping that will hopefully be OK. Also good to make sure the HVAC is set to max heat when doing that, so the coolant that runs through the heater circuit gets circulated as well.
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