Cooling fan after engine stop

Is it normal for a cooling fan to start up automatically after every trip, even in cold or rainy weather? I had the impression that it is only needed after some serious engine loads and in pretty warm weather. My Accord's fan seems to kick in for about a minute or so after a few seconds following every trip, even fairly short ones that could not have heated up the engine very much.

Reply to
Cameo
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"Cameo" wrote in news:ih2nao$hke$ snipped-for-privacy@news.eternal- september.org:

The fan is supposed to turn on after shutdown if the engine oil gets over a certain temperature (240F? I forget). If the fan is coming on at times when the oil cannot possibly be overheated, then the sensor is probably getting old and is kicking in too soon.

A new one is about $40 at the dealer.

Reply to
Tegger

Thanks, as always, Tegger. Now, if it was as easy to replaced as those alternator brushes, I would go for it. But isn't it also possible that perhaps the radiator tubes have lost too much of their heat transfer capacity (due to deposits) and that causes inadequate cooling? Probably not though because the temp guage seems to work normally as it usually stays below 40% of the scale.

Reply to
Cameo

"Cameo" wrote in news:ih4re2$e4o$ snipped-for-privacy@news.eternal- september.org:

Easier, I think. Except that it might need to be from under the car.

Were that the case, you'd have overheating at speed.

Then it's just a sensor. But I don't have diagrams to show me exactly where the sensor is on your car.

If you feel like spending $10, you can get 3 days of all-you-can-download from Honda's Techinfo site. You'll find the exact location of the sensor, including replacement instructions.

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Reply to
Tegger

I found that ECT sensor and it's impossible to get to without removing the distributor. It's right under it and you cannot get to it from below. either. Yeap, both the ECT sensor and ECT gauge sending unit are under that darn distributor. There is an easily accessible ECT switch B at the junction of the upper radiator hose and engine block, but I think the sensor is the one that should be replaced. The ECT switch A, that's also in a hard to reach location at the thermostat, is probably all right, too.

Since I see some oil leak at the distributor, I might have the mechanic fix the leak and replace the ECT sensor at the same time. That job would be over my head, I'm afraid.

Reply to
Cameo

"Cameo" wrote in news:ih7fgv$c3o$ snipped-for-privacy@news.eternal- september.org:

I don't think that's th one you want.

That's for the COOLANT, not the OIL.

You'd better spend the $10 to search Techinfo, or you may end up blowing a LOT more chasing the wrong rabbit.

Reply to
Tegger

Tegger wrote in news:Xns9E72BBBBCAE47tegger@208.90.168.18:

I'd search it for you, but the $10 subscription only lasts 3 days, and I don't have a reason to go back in right now.

Reply to
Tegger

I have access to the '94 Accord Service Manual and from what I could find the fan control is tied to the ECT stuff. I haven't seen anything on a separate oil temp sensor but I'll take another look. I'd rather not pay for something I can get free. Even if I can afford it.

Reply to
Cameo

"Cameo" wrote in news:ih8bpi$fbf$ snipped-for-privacy@news.eternal- september.org:

Only the US got fan-control that took oil temperature into consideration. Manuals meant for other places in the world may not mention such US-specifc stuff.

Be careful.

Reply to
Tegger

Thus spake Tegger :

Does the fan also run if the A/C compressor is "on" and the ignition set to "ACC" (or whatever it is, the manual is out in the garage)? I could have sworn that on those 100+ days when I was auto-x'ing that we'd pop the hood and turn the A/C on to cool the radiator between runs. There's nothing like 100+ air, 130+ pavement and 30 or so seconds of 1st & 2nd gear to warm up an engine.

Reply to
Dillon Pyron

Dillon Pyron wrote in news: snipped-for-privacy@4ax.com:

I've been thinking (bad idea, I know)...

How would the ECU know if the oil was getting too hot after shutdown? After shutdown, the oil mostly immediately runs down into the oil pan. The only possible increase in engine temperature could only come from the water- jacket area, where combustion takes place, and from where the oil would mostly drain in a few minutes after shutdown.

Maybe the after-shutdown fan operation /is/ controlled by the ECT sensor after all. Maybe oil temperature is just guessed-at by the ECU based on after-shutdown ECT readings. After-shutdown heat-soak /is/ a known phenomenon...

Question for Cameo: Do you find that the fan comes on quite a lot more often in general than you were used to, even with the engine running?

Reply to
Tegger

Well, I'm glad you realized that because I'd hate to disagree with the master. ;-)

Check these two links showing the relevant shop manual pages:

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Since the fan cools the coolant by forcing air through the radiator fins, it stands to reason that it is also controlled by the coolant temperature, via electrical feedback.

As to your question, I don't know how the fan behaves with engine running. I was only wondering why the fan would kick in shortly after I park the car even after relatively short trips in cold weather. But the fan does not run for 15 minutes as the shop manual implies. It only runs one or two minutes, depending on the engine temp, I guess.

Oh, in regard to my earlier alternator brush replacement issue, I've been checking the voltage during different electric loads and the voltage seems to pretty much hover between 14.2 and 14.8 while the engine is running. Even at idle. I find the following digital voltmeter I can stick into the cigarette lighter socket quite helpful in this task:

The display actually shows the voltage with 2 decimal accuracy, not with one as the above link indicates. The display part pivots and the shank length is adjustable a bit, too. Very handy gadget indeed.

Reply to
Cameo

"Cameo" wrote in news:ihb04p$6d4$ snipped-for-privacy@news.eternal-september.org:

If the fan is running too much with the engine OFF, it should also run too much with the engine ON.

If, that is, the same sensor is used to control the fan during engine-off AND engine on.

Durng winter in a cold climate, the fan ought to run very infrequently. It may never run at all if you're never stuck in extended stop-and-go traffic.

I've never checked the voltage to that level of detail, but it's probably normal.

Hey, that is cool. And it's cheap enough that I may pick one up just to have it.

Reply to
Tegger

Same here, thanks to Cameo for the URL.

Reply to
Tony Harding

Pleased to be of assistance. That's what this group is all about, isn't it?

Reply to
Cameo

Yup, but I think it's a good idea to recognize specific help.

Reply to
Tony Harding

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