406oc.co.uk

Hello,

I am a complete newbie to the world of the 406, but i have recently bought one for my wife and kids to run about in. The first problem that i have come up against is the temperatue gauge.

When driving it the other day, approx 100 miles of motorway, the temperature gauge read nothing at all for the first 50 miles then read fine for the rest of the journey, since then over the last 2 weeks the gauge has only worked for approx 10 minutes on a short run.

The coolant levels are all correct, and after a 100 mile journey i know its circulated fine, but i cannot seem to find any othr faults with the car or cooling system, except my wife reported a hot smell from the internal heating, but i cannot get it to give off this hot smell again, and she also repoted a complete loss of power for a couple of seconds, apparently when driving at 70mph it was like someone had turned the battery off for 2 seconds then reconnected it, the speedometer stopped working engine cut out etc... then a couple of seconds later it all came back, and no fault since.

Any ideas for a newbie to start with???

Many thanks in advance

Hello and welcome to club:)

sorry no real technical input on this other than "its character building" it is a pug after all

some one with a bit more intelligence will be along soon im sure to give you some advice

*looks about for the clever guys*

Thanks for the welcome,

I'm just hanging around waiting on the clever guys now...

... It's like waiting for a bus. I bet 3 will come along at once!!!

And i'm starting to believe your right, this Pug ownership will certainly be character building.

Here's waiting... lol!!!

I don't know about being clever, but the logical answer would be to replace the coolant temperature sensor. It's located at the right side of the cylinder head (looking towards the windscreen).I think it has a green electrical connector.

The search facility is a very good tool for finding answers.

Welcome by the way.

Yes,replace coolant temp sensor,on right hand side of the engine just behind the thermostat housing.It is green,and if you have an alloy thermostat housing,it will be a screw in sensor,which you can get anywhere for around £17.But if you have a plastic housig like mine,the sensor is a push fit type,whick i could only get from a Pug dealer,£18 with the o ring.
I just changed mine as it was doing the same as yours,also bringing up "coolant temp too high"on the display,even if the engine was cold,& also bringing on the engine management light & going in to safe mode,restricing the revs to 2500 rpm.That might be why yours id suffering power loss.
I changed mine last week & its been fine since.

Many thanks gents,

A good starting point.. i will be changing it out this week, and it is the push fit type, so if there is any precautions i should be wary of beforwe i tackle this i would be grateful to hear.

Once again many thanks, and i hope to return the favour one day!!!

I try to change these with the engine cold to save getting burnt fingers, also undo the pressure cap and release any pressure in the system then replace the cap, it helps to stop water flooding out too fast.

As above,& you will need to top up the cooling system after.I renewed my thermostat & coolant at the same time,so i needed to bleed the system.
Make sure you get a new o ring with the new sensor,but overall very easy to replace.

Thanks again gents,

Changed it out this afternoon, a couple of unsettling points though.

After changing the temperature gauge seems to work fine, the thermostat opened when the gauge was reading approx 85 degrees and the temperature settled on the 90 degree mark.

This is the un-nerving part.. i couldn't get it to read hotter!!! so the fan didn't cut in...

Is this normal for the HDi, does it maintain its own temperature really well. The pipe work was hot but not unbearable, and no smoke, but i had it running both on revs and idle, without moving for 45mins+.

No air appears to be in the water system and like i said gauge seems to be working fine.

Any ideas to put my mind at ease???

Also there is a "low brake fluid" warning (with complimentary bleep) occasionaly appearing, fluid is on top level, so it is becoming annoying. Any ideas again???

Thanks

Ha ha I can help on this one

as for it not getting over 90, thats fairly standard fair with the hdi, mine has had some right abuse in all weathers and it never goes over 90, these engines really hold the temp well, even on some of the hot days over here it has got well into the 28-30 degrees outside temp already (although right now its been raining for 7 days solid) and sat in traffic for 50 mins mine didnt budge over 90 at all.

and the low brake fluid warning is a famous 406 one too, it could well be your handbrake switch thingy-ma-bob, have a search through using the box up top on the right hand side for low brake fluid warning and it should throw up some answers for you,not a pricey fix from what i can remember, but certainly a common problem

Mine is doing an interesting thing....... One min my temp gauge will be reading 90 and all good next thing it's on 0 but still running fine.....few seconds or mins later it comes back reading 90

Would this effect prformance or economy as it's not boosting till 2,800rpm?

Could well be the sensor mastiff,as mine was doing the same,temp up,temp down,not reading at all after 20 miles of motorway.Mine also brought up"coolant temp high" on the display screen,& set off the engine light,& put the car into limp home mode,no more than 2500 revs.All sorted now though with a new sensor.