I recently started getting a small fault with the car. I'm pretty sure it's nout too major, I think I know what it is, just wanted some more opinions.

I have recently had the temp gauge, usually when I come to a stop, fall straight down into the blue, maybe for a couple minutes, then back up to the middle when I'm moving again. I've done a little bit of research, and from what I can work out there's more than one temp sensor (two or three, more?), monitoring gearbox, oil, EGR and ECU temps as well as the engine, and the gauge gives an aggregate reading of all? Am I correct in thinking this? Also, on a sidetrack, the engine note does change slightly when the car thinks it's cold. Me thinks some kinda choke, as it does occasionally make the noise when starting from cold, in summer kind you (only had the car this summer, so haven't done winter starts yet).

If I'm correct in the above, then I'm pretty sure that the issue is the gearbox temp sensor, as the fault never happened before I had my gearbox flushed. Maybe it's just loose or needs adjusting, but either way it didn't do it before I had the gearbox serviced. It just doesn't sound like a thermostat to me.....

Sounds typical thermostat symptoms to me

I had same just after fitting a stat from europarts - it failed slightly open after just a week with your symptoms

Fitted oem marked in from island 4x4 - sorted

The symptoms described are the opposite of what a dodgy thermostat normally shows - ie over cooling when moving so hot when stationary and cold on the move.

Well for me the first sign was it dropping temp when I came off the motorway to a stop (I remember the specific trip)

Then over next 2-3 days car took longer and longer to heat up, by around the 4th or 5th day it simply never reached temp do I changed it

I guess if yours is reaching temp ok maybe it is something else

kezbo1981 wrote:

The symptoms described are the opposite of what a dodgy thermostat normally shows - ie over cooling when moving so hot when stationary and cold on the move.

Afternoon.

An update; plugged the car into my friends Snap-On Verus diagnostic computer, fault code related to the oil temp sensor came up, can't remember exactly what it said, but I'm pretty sure it said something about going out of range. Anyway, the engine note change is over-fuelling ie choke, because the car thinks its operating at 0C, it is running rich, and the slightly dieselly burning smell would confirm this. Got myself a new temp sensor, although not fitted yet. Either it's that or the loom is no good. As first thought, the thermostat is OK..