Maserati 3200 Cooling

[LDM68]

On Saturday i had just got the 3200GT home after it had performed fine all day. I Parked it on drive, got out and as I walked away it started to release water / steam which appeared to be from the expansion tank release valve / wheel arch.

Once it had cooled down I refilled the expansion tank which was low / almost empty following the overheating. Once topped up there didn't appear to be any leaks so decided to start, all seems fine, came up to temperature as usual and no leaks. I released the lid on the expansion lid a little and there was a definate pressure escape so I would have assumed that if there had been any splits in pipe there would have been fluid loss.

Am thinking that for some reason the car over heated and caused the escape through the expansion tank lid valve. I didn't want to let the car get too hot but was around 90 and I didn't notice the fans coming on so thinking this could be the cause of the problem, the two big bulkhead fuses seemed fine. Any suggestions / thoughts?

Also had error light 0480 which i believe is main fan?

[Konimino2]

Check This

[gemini]

If the resistor is bad, I think you loose the slow speed for the fan but they still work, only at full speed.
Check the relays (in the engine compartiment, on the bulkhead, passenger side on LHD cars, I don't know for RHD).
Then check the coolant Temperature sensor (if defect, it's the same as the fiat brava/punto/marea JAEGER 40218301, you can check it with a Ohmmeter
@20°C 2.5 Kohm
@90°C 0.230 Kohm

[LDM68]

Many thanks for the replies, I checked the fuses and all seem to be OK, next i checked the fans with a direct 12v feed and they are working, however discovered the connectors are shot. so hoping this is the issue but will probably replace resistor too while i am at it.

[Konimino2]

Not good

[Dom3200]

When my temp sensor was down, I had the same symptom. When it's down it's undermesuring the temperature by approximately 20c, a lot...

[LDM68]

Hi, where is the temp sensor? How can you tell it is bad? The two fuses and relays, are they 1 for easy fan or 1 for each speed / temp trigger?

[LDM68]

Ok firstly sorry for another post on this but thought it worth starting a fresh post now i have a better idea.
When the car gets hot the fans are not coming on at either stage and then pressure builds and water is forced out of the expansion tank overflow / release valve.
I tested both fans with a direct feed (connector at top of fan housing) and they then spin, however I noticed the connectors were in poor condition so changed them - the fans still didn't come on when the car got hot.
I checked the two 50A fuses on the bulkhead and both are ok, i checked there was power to them and there is.

I removed the two fan relays and then bridged the two large contacts (as if relay was closed) for the right hand relay (looking from the front of the car), switched battery back on and the fans sprang into life.

I then did a similar thing for the left hand relay, this time nothing, I assume this is the slow / first stage circuit and that this means the resistor is bad? does a bad resistor mean that the fans do not come on at first stage?

Next i decided to check the relays, resistance for both relays pins 85 & 86 was 63.2 - 63.5
Pins 30 & 87 un-energised was 1 (same as not connected to anything). Energised was 0.3.
I think this means they are fine?
In which case i assume there is postentially two fauls:
Low speed not working due to resistor fault.
High speed (and possibly low speed relay not being triggered for some reason?

Any thoughts on where the fault could be and / or anything i have done wrong appreciated.
Looking more like the temp sensor as suggested maybe?

[LDM68]

Resistor swapped, as others have suggested sensor may also be faulty so will swap that next.

[LDM68]

Sorry for the delay in replying and hopefully concluding this thread, so both resistor and sensor have been swapped and everything "seems" to be working as it should be. To be honest I was unsure if the sensor was bad or not but suspected it was reading low so thought changing it was the sensible thing to-do. Hopefully all will be ok now! Many thanks for the help.

[gemini]

Good news!
Enjoy your 3200, it's a car we are very found of on Maseratitude.

[Dom3200]

Glad she's OK now enjoy!