Xantia MK2 cooling fan temperature operating settings

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admiral51
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Xantia MK2 cooling fan temperature operating settings

Post by admiral51 »

Hi Guys.

Just asking for the temperature that the cooling fans should kick in at slow and full speed.
Vin is in my sig but it is a 2.0 HDi 90 bhp for clarity.

Cheers

Colin

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Re: Xantia MK2 cooling fan temperature operating settings

Post by ozvtr »

I cant tell you the specific temperature for your specific engine, sorry.
Most engines operate at about 90'C. Thermo fans typically kick in at about 97'C and run at full speed at about 105'C. Now, there are latitudes in the specifications of the sensors and the temperature gauge in the instrument cluster. So if you intend to use the temperature indicated on the cluster there might be a few degrees error in those numbers. So these are very rubbery numbers indeed!
Generally, if the temperature needle sits half way between the upper and lower temperature marks (whatever temperature that may be) on the gauge, that's 'normal'.
If you want to test if your cooling fans are working, depending on the ambient temperature, from "cold" an engine can take between 15 and 20 minutes (idling, not driving) to reach the temperature required to turn on the fans, if the ambient temperature is 25-30'C. If the ambient temperature is colder it will take longer. Even then, the fans might only run for a minute or so at low speed before switching off again.
It is common to not hear or see the thermo fans working. Most of the time the thermo fan(s) run because the air conditioning is running. Actually the whole idea is to design a system where the fans don't run (that much). The fans draw a considerable amount of current from the alternator, which the engine needs to generate, which consumes fuel! Under some circumstances even using the air-conditioning may not cause the fans to come on. The fans are driven by the LOAD on the air-conditioning system. No load, (not a hot day) no fans.
If you are not getting any over heat warning and the temperature gauge only fluctuates a few degrees around 90'C when driving, then I wouldn't worry.

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white exec
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Re: Xantia MK2 cooling fan temperature operating settings

Post by white exec »

Hi Colin,

I've had a scour though all the editions of the Xantia mechanic's booklets, and can't find the cut-in/out temp figures for Lo and Hi speed.

Maybe someone will be able to dig them out from some Xantia workshop pages.

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Re: Xantia MK2 cooling fan temperature operating settings

Post by admiral51 »

ozvtr thanks for the reply.
I have had a problem with the fans for a couple of years and i have been trouble shooting it again this week. :oops:
I have the fans running as they should at the moment [-o< ( ie A/C and full speed with stat sensor removed) but the blinkin engine runs so cool it takes for ever to get hot so wanted to have an idea of when they should kick in so 97 and 105 is a good shout.
Chris i also had a look through and could not find any info and thanks for taking the time to look.

Colin

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Re: Xantia MK2 cooling fan temperature operating settings

Post by Armidillo »

Perhaps do what the old timers did in winter, or when crossing deep water - stick a corn sack or a sheet of cardboard over the front of the radiator!

OK - fans in front of radiator rather spoil the plan, but reducing the air intake as much as possible should help to reduce the cooling efficiency and speed up heating - a small tarpaulin or rubber backed curtain draped over the grille might help.

You might have to wait for summer to get the engine hot - but I suppose it's hard to predict which day it'll happen this year :).

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Re: Xantia MK2 cooling fan temperature operating settings

Post by Armidillo »

Just checked Haynes - the nearest they come to documenting the cooling fan cut-in temperature is the following statement:

"If a fan does not appear to work, run the engine until normal operating temperature is reached, then allow it to idle. The fan should cut in within a few minutes (before the temperature gauge needle enters the red section...)."

Doesn't even seem to recognise the Low and High speed operation. Not really very helpful...

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white exec
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Re: Xantia MK2 cooling fan temperature operating settings

Post by white exec »

Hopefully the fan temp data can be found, but if the engine is running cool (can only be verified with a thermometer check, eg on the water outlet housing), then that will be down to the thermostat. However chilly it is outside, a properly working 'stat will allow the temp to get up to spec. If the 'stat is faulty, or leaky, cold weather can depress the temp by a huge amount.

Other possibility is an inaccurate gauge (or gauge sensor), but this can be checked with a thermometer too. One of the non-contact I.R. ones is probably easiest to to use; cheap enough these days.

The engine fans' only job is to prevent excessive temperature rise - the thermostat cannot do this; it's job is to provide a minimum temperature for the system.

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Re: Xantia MK2 cooling fan temperature operating settings

Post by admiral51 »

I really ought to clarify my use of the words "running cool".
The engine temp gets up to 80 ish on the gauge as it should, it very rarely gets up to 90 even in stop start traffic, thermostat works as it should. Just struggling to actually get it to a temp where the fans should kick in so i can test the operation of that part of the system, it is the only part i have yet to be able confirm.

Colin

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Re: Xantia MK2 cooling fan temperature operating settings

Post by white exec »

Usual way is to get it well up to temp with a drive, then park up, and leave the engine idling. It has to get hotter that way (nothing much to cool it), and at some point the fans should cut in. You can check the actual temp it does so.
Unlikely that it will ever get to Fast fan speed by this method, because Slow speed will cool it first.

One way of skipping Slow speed would be to disconnect one of the fans, so they can't operate in series (=Slow). When the Fast speed temp is reached, the still-connected fan should come on (as it would when both fans operate in parallel).

Rather frugal, our diesels . . . little fuel, little heat. Fast speed only likely to be triggered by some serious prolonged hill climbing, preferably while towing, high summer, a tail-wind, and the A/C switched off. :chin: