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Full Version: 146 1.6 Engine Over Heats (fan Don't Kick In)
Alfa Romeo 145 - 146 Forum > Technical > Boxer Engine Only Oily Stuff
iomran
Hello Everyone ,
I hope someone could help me here as my fan don't kick in even after the engine temp exceeds 110 causing the red light to blink after a short drive blush.gif
I noticed that the radiator is very hot from the top and normal from the mid and bottom . I suspect that the fan sensor is placed at the bottom of the radiator which is not very hot (may be blocked inside in the bottom) and that's why it don't sense much heat .
I have tested the thermostat and it do opens when the temp exceeds 90 degrees .
Does anyone knows where the fan sensor is located on the radiator ?
Does anyone have a picture ?
GialloEvo94
Which 1.6 engine is it...Boxer or Twin Spark?

Have you checked that the fan actually works by temporarily connecting it directly to the battery?
iomran
QUOTE(GialloEvo94 @ 14th June 2007 13:46) *
Which 1.6 engine is it...Boxer or Twin Spark?

Have you checked that the fan actually works by temporarily connecting it directly to the battery?


It is a boxer . The fan do work with the A/C and also for very short instances when the temp. is very very high on the dashboard .
GialloEvo94
There is a thermostatic switch screwed into the radiator on the right side (looking into the engine bay from the front). It's just above the bottom hose and is in the same place as on the early Twin Spark engines...

http://forum.alfa145.com/index.php?s=&...ost&p=94367

Try unpluging the electical connector and shorting the two connections together inside the connector. If the fan comes on (with the ignition also on) then you know the issue is with the thermostatic switch.
spiffm
I had the same problem and it was the thermostatic switch the GialloEvo94 said. Another problem with the boxer engines that causes engine heat to built up is the water pump. It is plastic and it cracks. That way the pulley spins but the collant doesn't circulates in the engine.
iomran
QUOTE(spiffm @ 14th June 2007 20:49) *
I had the same problem and it was the thermostatic switch the GialloEvo94 said. Another problem with the boxer engines that causes engine heat to built up is the water pump. It is plastic and it cracks. That way the pulley spins but the collant doesn't circulates in the engine.


Thanks to both of you . This is much appreciated . I will check the thermostat then but why don't you suspect some blockings in the radiator ? I don't have any clue from the previous owner or the receits if the radiator was ever changed , however it looks very new from outside. Also Do you know whether this thermostat goes into the ECU or directly to the fan . I am just afraid of any ECU disasters . no3.gif
Regarding the water pump , I am due to change the Cambelt so it should be a good chance to change the water pump as well .
To change the 2 Cambelts , there are 2 pullies as well . Do u know I have to change the 2 pullies as well together with the cam belts ?

Regarding
GialloEvo94
It's unusual for the radiator to just become blocked which is why I wouldn't suspect that being the actual cause (although I could be wrong as it's not impossible).

The connection from the thermal switch screwed into the radiator does not go through the ECU in any way so you won't damage the ECU by shorting the connections which goes to that thermal switch. You can find a wiring diagram for your engine cooling system on page 3 in this document (click to open link).

You should change the water pump when the belts are off. I'm not sure whether changing the pulleys on the Boxer are a "requirement" when changing the belts but I would certainly recommend doing so for peace of mind because the bearings in them will not have an infinite life. I'm sure one of the other Boxer engine members will be able to advise you better but if it was me, for a bit more cost I would just change them anyway.
spiffm
I have shorted the connections ages ago and never changed the switch. If you dont want to change the switch there is not a problem. The switch is just for altering the speed of the fan. The only downfall is that it draws more current because it works at the high speed only
iomran
QUOTE(spiffm @ 15th June 2007 11:09) *
I have shorted the connections ages ago and never changed the switch. If you dont want to change the switch there is not a problem. The switch is just for altering the speed of the fan. The only downfall is that it draws more current because it works at the high speed only

Thanks Spiffm and Giallo for your advices .
Today I have been to the mechanic but no change . Have tried to short the circuit on the wires to the thermostatic switch .Everything was perfect , 2 wires position made the fan work in low speed .On the other postion , the fan worked at high speed . Now I think there is no electric issue .
Also I tried 2 thermostatic switches and both failed to make the fan kick in at any speed . huh.gif

The technician told me may be there is some air in the water cycle that has to be removed and then nothing changed .

What I noticed is that the hose going out from the radiator to the engine (that one right above the thermo switch) is not too hot while the whole motor is hot up to 100 deg. That make me think of some blocking in the radiator interior or a problem in the water pump as spiffm said not giving much push to let the water circulate .


Although the radiator flushes water from the upper small hose while testing the cycle,I still think there might be some radiator blocks in the bottom because it was still getting out the old green coloured cooler although it was flushed 2 times before and many times today .
This is a little bit strange situation .
iomran
Hello . I have changed the water pump it was completely damaged and the temp should be fine now even with AC .
The technician says that it is still high .
Below is a snap shot for the temp . with 2 states . Do you see this is normal in hot sunny day ?

[attachment=5580:DSC00140.JPG][attachment=5579:DSC00130.JPG]
taz146
That the point that the fan takes place so the temp seems ok. Also boxers' temp rises much easier than TS's especially when driven in low revs and with high temps.After the fan starts working it should fall a bit if you r in traffic. BUT if you drive to the motorway and the temp still remains at that level then it is not ok.

Do know that boxer engines' temp - especially in hot days and while in traffic- rises fast and keep that temp unless they are driven to motorway for example. If the temp still remains high at all occassions you should consider a new radiator possibly.
iomran
Do you know the temperature right below 120 . Is it 100 degree . If it is so , it should be ok .
Or is it linear scaling ?
taz146
QUOTE(iomran @ 28th June 2007 15:21) *
Do you know the temperature right below 120 . Is it 100 degree . If it is so , it should be ok .
Or is it linear scaling ?
Yes it is supposed to be 100-105
AforAlfa
QUOTE(taz146 @ 28th June 2007 16:35) *
Yes it is supposed to be 100-105


blink.gif blink.gif


eh??? our 33 16v runs at 80 in traffic, on a hot day!!!

i would be tempted to whack a new thermostat in, and run a higher concentration of antifreeze.
taz146
QUOTE(AforAlfa @ 29th June 2007 21:06) *
blink.gif blink.gif
eh??? our 33 16v runs at 80 in traffic, on a hot day!!!

i would be tempted to whack a new thermostat in, and run a higher concentration of antifreeze.
That is even better but it usually runs at 100 at traffic where it is the point that the radiator fan takes place. Mine only stays at 80 in traffic when i have the A/C on
iomran
QUOTE(taz146 @ 30th June 2007 11:55) *
That is even better but it usually runs at 100 at traffic where it is the point that the radiator fan takes place. Mine only stays at 80 in traffic when i have the A/C on


Hello Thanks to all specially Taz . It turned out to be blocked radiator . I went to a shop who cleaned it from inside . There was a lot of dust blocks in the bottom . Temperature is ok now where I didn't see it like this before .
Thanks again
GialloEvo94
QUOTE(iomran @ 29th December 2009 12:42) *
Hello Thanks to all specially Taz . It turned out to be blocked radiator . I went to a shop who cleaned it from inside . There was a lot of dust blocks in the bottom . Temperature is ok now where I didn't see it like this before .

My word...that took a long time to get sorted out...2.5 years unsure.gif

Anyway, glad you've finally got it sorted thumbsup.gif
Fuel
I think maybe I have the same problem as Iomran.
My car when stopped goes almost up to the 100 degree line in the temperature gauge before the fan kicks in.
I think the fan is kicking in at more or less 97 degrees celsius.
As I have an 1996 Cf1 engine, and the fan switch is located low in the radiator, I think maybe the hot water is not reaching properly
the switch!
The previous owner used to use tap water in the cooling system (as all the "smart" people down here does) and it was quite dirty
when I bought the car!
I flushed it... putted new destiled water with additivies inside... the car runs awesomelly when gets some air in the front, but it lasts
a bit untill the fan kicks in when stopped in the traffic!

What do you think?
In which temperature in the gauge should my old CF1 kicks in the radiator fan?



zhoey
QUOTE(Fuel @ 22nd January 2012 14:56) *
I think maybe I have the same problem as Iomran.
My car when stopped goes almost up to the 100 degree line in the temperature gauge before the fan kicks in.
I think the fan is kicking in at more or less 97 degrees celsius.
As I have an 1996 Cf1 engine, and the fan switch is located low in the radiator, I think maybe the hot water is not reaching properly
the switch!
The previous owner used to use tap water in the cooling system (as all the "smart" people down here does) and it was quite dirty
when I bought the car!
I flushed it... putted new destiled water with additivies inside... the car runs awesomelly when gets some air in the front, but it lasts
a bit untill the fan kicks in when stopped in the traffic!

What do you think?
In which temperature in the gauge should my old CF1 kicks in the radiator fan?



Yes. In the tropics the temperature gauge shows almost 100C especially after a hard run.
I have had this on my 15 year old 146ti, and I had the car since new......no problems.

The lo-speed fan only kicks in at about 90-94C and the hi-speed fan starts running between 95-99C.

Added to all this, the fan thermostatic switch is located at the bottom of the radiator where the coolant is a few degrees lower than at the top of the engine where the temperature gauge sensor is located so go figure.
iomran
QUOTE(zhoey @ 30th January 2012 03:10) *
Yes. In the tropics the temperature gauge shows almost 100C especially after a hard run.
I have had this on my 15 year old 146ti, and I had the car since new......no problems.

The lo-speed fan only kicks in at about 90-94C and the hi-speed fan starts running between 95-99C.

Added to all this, the fan thermostatic switch is located at the bottom of the radiator where the coolant is a few degrees lower than at the top of the engine where the temperature gauge sensor is located so go figure.

To Fuel :
I have been through this problem for long time as mentioned and it turned out to be bottom blocked radiator .
This causes temprature not to be well distributed in the radiator especially at the bottom which don't become so hot like the top and causes the fan to kickin late if it does . You can test it with your hands at the top and bottom of the radiator too and you may find the top hoses more hot than the low ones . When I removed the 2 side radiator packets I found lot of sand , mud ,rust ...etc .
Try to change the radiator with another good one or take it off , remove the packets and clean it but be sure to make it well sealed after the cleaning process .
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