Engine temp too high ??

[Spacecowboy]

I have just started getting an intermittant problem. The dash 'STOP' warning comes on and after beeping the message 'Engine Temperature Too High' is displayed on the console. Meanwhile the temp gauge stops working.
The first time it happened, I started slowing down and was ready to pull in to check what I could, when the 'STOP' warning went out and the temp gauge started working again. It is happening more often now and whether the engine is just warming after a few minutes, or after a couple of hours hard driving on the motorway.
The car is a 2004 406 2.0 HDi (90ps) 'S' Estate, at 120,000 miles.
Any help would be appreciated.

[steve_earwig]

Weird. If it wasn't for the multiplex I'd hazard a guess there's a short between the supply for the switch and the feed for the display but I know it won't be that obvious. Maybe you should start by checking out as a simple temp gauge not working and head for the sender on the thermostat housing. Perhaps you're getting the message because there's no "engine temperature too low" warning available to the display

[Doggy]

Have you checked the obvious, - temp. sensor connections etc.? It sounds like you're losing the signal from the sensor briefly, rather that a genuine water temp. issue.

[mbell666]

I agree sounds like dodgy connection between temp sender (thermosat housing) and ECU/BSI or where ever it ends up.

Could be also be the temp sensor, had problems with a old rover with intermittent temp sensor, on more modem car would have probably caused the problem your seeing

[Doggy]

Can't be certain with Spacecowboy's '04 car, (my Haynes is 99 - 02). That shows temp. sensor direct to engine ecu, (which controls fan), and clearly implies, (but doesn't show), link between ecu & instrument console....

[Welly]

It's the cooling fan gubbins at the front.


Have a read of this....viewtopic.php?t=1452&start=0#p13555

[steve_earwig]

Don't think that would make the gauge drop to zero.

[Welly]

I thought that but it'd be worth looking eh?

Maybe the coolant sensor wire/connector is a bit iffy?

[mjb]

Aye, my money's on a connector. Finding it's going to be a bitch though if it's not the connection on the sensor itself...

[Doggy]

Sometimes the pins just get oxidised & unplugging it & plugging it back in a few times sorts it out, at least for a while.

[Spacecowboy]

Cheers guys, I have had a quick look at the connectors that I can. Getting into the fan in front of the rad might be a bit of a faff, but the ones I can see look ok. There doesn't seem to be anything coming from the thermostat body, but there looks like something from the head near it.
I'll have another go and try and find what I am sure is an electical problem 'cos when the gauge starts working again, it is usually at the 70 mark when warming and 90 when hot. I've never seen the gauge over 90. There is no loss of water and my heater doesn't seem to be effected.
If I find it I'll put the details on here.

[jasper5]

I had this problem a couple of years ago.

The fault is caused by a faulty sensor.At the side of the engine on the right hand side...viewed from the front of the car...there are two sensors, If I remember correctly, the sensor has a green top, I think there's a blue one as well right next to it.The sensor is held in by a clip slotted in sideways, it takes about 5 minutes to change.

I think it's the engine management coolant sensor, but i'm not sure.I think it cost me about 12 quid.

[Spacecowboy]

Thanks.
I can't find my Haynes manual, so I'll get another and try and buy all the bits and pieces before I tackle it.
I don't have time to keep it off the road.
Anyone know of the best place to buy spares online? (Preferably with a decent parts listing)
I'll have a dig through the forum in case its a question already answered.