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Couple issues - temp and fan

2665 Views 13 Replies 3 Participants Last post by  Dean...
Hi all

I'm am Aussie with a 1.6L turbo. As of this morning, the fan runs presumably at full speed all the time while the engine is running. The engine light DOESN'T come on, but I do get a message on the dash telling me the car needs a service. I have an OBD reader and there are no codes. Any ideas what is going on?

Also, does anyone know what the normal operating temp is?

Thanks

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Low coolant (they leak coolant in quite a few places in the US models) or a bad temperature sensor are common.
Low coolant (they leak coolant in quite a few places in the US models) or a bad temperature sensor are common.
Coolant level in the tank hasn't changed. The temp showing on the dashboard seems to be working as normal.

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Coolant level in the tank hasn't changed. The temp showing on the dashboard seems to be working as normal.

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There are two temp sensors - an upper and a lower. If they don't agree, the car will go into a default 'limp' mode and run the fan on high as a precaution.

If the MAF was unplugged for any reason, or has gone bad, that can set the fan into scream mode too.

The service light - is that just for an oil change?
There are two temp sensors - an upper and a lower. If they don't agree, the car will go into a default 'limp' mode and run the fan on high as a precaution.

If the MAF was unplugged for any reason, or has gone bad, that can set the fan into scream mode too.

The service light - is that just for an oil change?
Thanks, but the car is definitely not in limp mode. I'm an Uber driver and just finished driving for 8 hours, all while this issue is present. The car is driving as normal, other than the loud noise of the fan running at full speed.

Again there are no fault codes.

It's not a service light, it's actually a 3 word sentence saying something like "Service Vehicle Soon". Sorry I can't tell you the exact message, I'm in bed and about to go to sleep.

I appreciate you sharing your thoughts!

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Thanks, but the car is definitely not in limp mode. I'm an Uber driver and just finished driving for 8 hours, all while this issue is present. The car is driving as normal, other than the loud noise of the fan running at full speed.

Again there are no fault codes.

It's not a service light, it's actually a 3 word sentence saying something like "Service Vehicle Soon". Sorry I can't tell you the exact message, I'm in bed and about to go to sleep.

I appreciate you sharing your thoughts!

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Yeah, it just does that mode in case one sensor does not agree with the other.

Sometimes, but not always, there's an overheat message displayed. Sometimes the fan just runs full out.

If you have an OBD2 tool, try seeing if it will display temperature values for you.
A fault in the A/C system can cause the fan to scream. Does it stop when you shut off the A/C? Note that the A/C sometimes runs even even if you haven't turned it on. Defrost and floor heat will do it.

Also, does it scream continuously, or cycle on/off? The US models have a bad habit of changing from low-medium-high to off-off-high. So, instead of running low or medium, things build up until to goes high.
Thanks for everyone's posts, very much appreciated!

I think it is just a problem with the fan, as the temp displayed on the dash is the usual temp, but I will check it with my OBD reader later today.

When I first started it this morning, for about 10 seconds the fan was off, then when it started it was on full, which is what it did the entire time last night. Seems like it probably is the speed control acting up, as suggested. Tested it with the air con on and off and it always does the same.

It's probably just a coincidence that the dash telling me to service the car soon only started when this issue started.

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I've read somewhere that the speed control is done using resistors; anyone know what the values of those resistors are?

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UPDATE

This morning I drove the car.... The message on the dash never displayed and the fan was running how it should. It ran as it should for a couple hours, until tonight; I again get the message and the fan is running at full speed.

Does anyone know what reasons that message displays for? I get no error codes.

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No one have any ideas?

The night before I played around on the engine bay and squeezed a couple radiator hoses, was thinking there may have been an air bubble somewhere, particularly since the very next morning the car ran as it should, but I did the same thing this morning before I drove it and the issue is still there: I still have the "Service Vehicle Soon" message displaying and the radiator fan is running at full speed.

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I forgot to let you all know, that the OBD Reader gives me the same normal temp as what is displayed, so it isn't running hot.

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The car has multiple temperature sensors. If they're not in reasonable agreement, the car doesn't know what's right and will run the fan on high.

I don't have any suggestions other than what's already been suggested.
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Thank you.

So am I correct in assuming that not all temp sensors display in the computer when using an OBD reader?

Any idea of where all the temp sensors are located? Or know where I could find that info?

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