Hello Doodlbug,
I am replying here to your helpful post on my
4200 CC : PROBLEM STARTING WHEN ENGINE HOT
topic since strangely although I received an email from the website giving me your very helpful reply when I go into my post there is no trace of it. Is it the same for you? If so perhaps you could repost your reply to me and I'll then repost my reply (below) so as to maintain the replies chain.
I've spent some time looking into part number 196622, worked out where it must be on my LHD car (up below the steering column), and managed to locate it.
On my facelift (MY2006) it's actually part number 219367. (On the Scuderia Parts diagram 219367 is shown as being for 2005-2007 coupés, whereas (strangely also...) 196622 is shown as being for 2002-2004 coupés and 2005-2007 spyders - how weird is that? Perhaps the spyders didn't get the same facelift features?) They are both shown as being "INTERFACE CAN FOR INSTRUMENTS PANEL", and both are item 1 in the respective diagrams.
Now here's my query. Does the temperature sender sends its signal via the "INTERFACE CAN FOR INSTRUMENTS PANEL", which then (a) sends a temperature to the temperature gauge AND (b) also sends a temperature signal to the engine management which takes account of it in deciding the petrol mixture? That is to say that my true engine temperature higher is than the reading on the temperature gauge due to the problem with the INTERFACE (196622 or 219367)? Once you had your new 196622, did your temperature gauge then read closer to 90°C,please?
Anyway the good news is that for once the part is readily accessible, which makes a very nice change. The bad news is that it may not be available new ("AVAILABLE TO ORDER" on Scuderia Parts.
I plan to still go through the steps in my post to see what happens - and if that doesn't lead me to the solution I'll most certainly try to buy a 219367.
Thanks again for your helpful reply,
Tony
Hi Tony,
I'm not sure what happened to the post but the one you have quoted is still there.
I don't know the communication protocol used by the Instrument CAN Interface, but the car had the following symptoms.
It would start normally from cold.
The radiator fan would always run immediately the car was started, whether or not the engine was warm.
The temperature gauge never indicated higher than about 70°C even on very hot days in slow traffic.
The car would be very difficult to start from hot and there was a strong smell of overfuelling.
Occasionally, the Check Engine light would illuminate. Checking the fault codes showed an engine temperature sense fault.
After replacing the Instrument CAN Interface, the temperature gauge reads 90°C in normal conditions and higher if stuck in traffic, where the radiator fan will come on. The radiator fan only comes on if the temperature is well above 90°C. It no longer comes on if the engine is cold when it is started.
I no longer have hot start problems and the Check Engine light no longer stays on once the engine is started.
I hope you get it fixed soon. It took one main dealer and two independent garages a total of 4 attempts to cure it after they tried changing the temperature sensor and the thermostat.
