355 owners only! More data samples needed! Anonymous poll!

Being as how it does not go below 8, your thermostat is fine. However it is getting on the hot side .......... make sure your driver side fan switches on at 190°F (per factory spec) ......... you may also benefit from a coolant flush and make sure to use deionised water (super market) when you mix the new coolant .......... other than that ....... I have seen 'redline water wetter' bring the temps down too.

 

Has this been the way it has always been or just after the major? If you are stuck in traffic on a very hot day, the temps will not stay at 190° .......... going to the 11 or 12 mark may happen on those hot days ....... a new radiator is more efficient ........ if you have to drive in that weather ...... you can also adjust your coolant to deionised water ratio ........ up to a max of 60% water to 40% deionised water ....... that would add more cooling capacity and along with redline water wetter, should tip the scales for the better.

Do you have a challenge grill? That can play a big part in operating temps as well.

 

15 .. ........... if it got that high ......... I am almost certain one of your fans is not working ......... with your car sitting and at 190°F (10-11) both fans should be working ............ put your hands in the vents to feel if air is flowing ....... it should be very obvious .......... sometimes the fans themselves loosen on the shaft and you will hear the motor ..... but no air will be flowing ....

 

The temps you describe for 'just sitting' are about right. It is strange that 'sitting' in the driveway vs 'sitting' in traffic results in such a wide temperature discrepancy ............. if both your fans are running and are not slipping on the shafts ......... then I am running out of ideas ..........

You would definitely benefit from a challenge grill. What kind of exhaust are you running?

 

Good point .......... I have mentioned the gauge is not the sole indicator and the main reason we are using it, is because that is all we have and it is very convinient ... .

One clue that the gauge may be close enough and usable for this test, is the fact that the 'gauge sender' and the 'ECU sensor' are within 2-3 inches of each other and sample from the same coolant path. As per the manual, the ECU electronically triggers the coolant fan at 190°F using its own 'separate sensor' reference ........... and it coincides with the gauge reading at 190°F ... which uses a 'completely different sender' reference ......... that would show that both match the spec per the manual ...... OR ..... both be in error, in the same direction and the same magnitude ........ which would unlikely, since they are completely independent parts .......

 

Yes I got mixed up .............. the LH fan is triggered by the thermal switch on top of the left hand radiator at 190°F ........ BUT ........... the RH fan is triggered by the coolant temp sensor for the ECU .... the one I talked about earlier, near the gauge sender ............. when troubleshooting I had this one disconnected and the RH fan did not come on at all .......... turned the car off and reconnected it and the RH fan came on as normal.

.......... there is no fan electrical thermal switch triggered the oil .... only a thermostat ......... the sender under the oil tank is for the oil temp gauge not the ECU or fan ............ this became even more clear .... because the F1 models do not have one of these senders under the oil tank ......... and no oil temp gauge either ........... at least in stock condition ......

So my point was, one independent thermal fan switch and one independent gauge sender match at 190°F (per owners manual)....... so they can be semi-checked with each other ...

 

I think there must be some mis-communication/understanding ........ ALL 355s have #40, which is in coolant path AND triggers the RH Fan. It also serves as the ECU engine temp monitor (that is the one I disconnected which disabled the RH fan, on my previous post) ...........

To reiterate, F1 355s 'do not' have the oil temp gauge sender under the oil tank, next to the oil drain plug and of course no oil temp gauge .....

 

I posted some technical info links (just above diagram) on post # 13:

http://www.ferrarichat.com/forum/showpost.php?p=141643790&postcount=13

This issue was identified over a period of time, while troubleshooting a few 355s with random 'slow down' lights ...... some of which occurred right after start up ....... after ruling out thermocouples and their ECUs ....... this issue persisted and also manifested itself in hotter than normal exhaust tubing temps (just after collector), taken via pyrometer, we saw 800°F - 900°F+ (should be around 400°F - 500°F at this location) this was just after casual driving ........ this even occurred on 355's running test pipes and free flow exhaust (so a plugged cat was ruled out) ...........

This culprit was difficult to find because troubleshooting was being done while the car was sitting, which brought coolant temps to 190°F and temps normalized/saturated ........ some of these cars even made stops at the dealer, they ran tests with the car sitting .......... no findings ........ it was not until I tested one on the highway, that showed the coolant discrepancy ...... "hey we got something" ....... since the factory thermostat fails to favor flow mode, it had to be changed no matter what ........ after the thermostat was changed .......... all these random 'slow down' lights went away, exhaust temps went down to normal and coolant temps stayed within spec ........ we did the same 'highway test' on the other 355s and those thermostats were suspect too .......... once changed, those 355's rich running issues went away also ....... ........... so then I wanted to know how many other 355's had suspect thermostats ....... hence this thread, to bring awareness.


Here is a random google search that describe rich running due to a faulty thermostat:

https://www.google.com/search?q=thermostat+running+rich&aq=0&oq=thermostat+running+rich&sugexp=chrome,mod=2&sourceid=chrome&ie=UTF-8

.

 

.......... in addition to the above, I used a ScanTool OBDII wifi reader with my laptop ...... it showed o2 sensor, MAF, coolant, RPM outputs etc. in 'real time' ...... this was done with the car sitting ........ I checked the evap systems among many other things over a long period ............ long story short, it was clear the cars were running on the rich side at some points ..... but the real question was why ............ then the 'highway test' which brought those temps below spec was a clue to a cause, not just another symptom ............ every one of those 355s went through at least one set of cats .......... if the cause was not found, it would have resulted in more damaged exhaust components and hastened cylinder liner wear, due to the excessive fuel thinning cylinder wall lubrication.