Peugeot 206 Heater matrix and coolant manifold (thermostat and temperature sensor) replacement

[MattBLancs]

New O-rings on the pipes. Spot of red rubber grease too, help things slide together. New matrix supplied with three bolts (and three square nuts to slot into the pipe's fittings) so three fixings installed. Hopefully more consistent sealing pressure on the O-rings, but puzzling why only one used as standard.

[MattBLancs]

CD changer connection for info.

Closure plate quick repaint and reinstalled.

Coolant topped up (eurocarparts, concentrated -20°C when diluted 1:2 coolant:water. Water= garage roof rain barrel water in my case (less fluoride than tap and free!)

[MattBLancs]

Under the air filter housing, this hose was being chaffed.

Chaffed hose

So, add ingenuity, 3 cable ties and a small slice of old mouse mat =

Also tested the "glow plug coolant heater thingy" all read around 1.2 ohms, so apparently functional still. Sure they are original! Contacts cleaned up

Glow plug coolant heater contacts before and after

Reinstalled (rubber caps followed but no picture)

[CitroJim]

The good work continues!

At that point I had somewhat of a deviation from the video guide. "Just distort the dashboard a little to get clearance for the matrix to come out"

Gosh Love that instruction That's a heck of a way to do it but I guess it saves removing the entire dash...

How well do you find the glowplug pre-heater works Matt?

[MattBLancs]

Gosh Love that instruction That's a heck of a way to do it but I guess it saves removing the entire dash...

How well do you find the glowplug pre-heater works Matt?

Yes, it's a bit hard for my "mechanical sympathy" tendencies to tolerate, but a massive time saving, so worth a try.

I'm not sure if the video author 206's dashboard had been out previously (and by extension, was missing some fixings) or if the earlier ones (his was a DW10, which gave way to the DV6) were slightly less robust. But there's no way I could get enough flex by hand to get it out as shown! Foot in a strap worked really well though.


Glow plug heater thing - I'm pretty sure it does contribute meaningfully, I left it idling whilst squeezing hoses etc to encourage air out the system, then bit off faffing lubrication of the isofix seat base. Came to hoover the footwell of the rivet drilling fragments and there was meaningful warmth in the cabin. Very little load on the idling engine (headlamps and blower fan only) so guess a good proportion of the heat was the little glow plug thing doing its job.


Has anyone ever changed the plugs in one of these? Am sure I read XUD ones are different but might fit? Anyway, I'm not attempting it at present as seems is no need!

[CitroJim]

That's good to know about the pre-heater Matt... I saw once what happens to them if they are activated when there's no coolant around them... It does the housing no good at all.. That was on a Xantia HDi...

I once had a late Xantia HDi with the diesel fuelled Erberspacher pre-heater and that, on a freezing cold morning was a boon. My journey to work in those days was six miles and in that time the engine barely got warm enough to open its thermostat! Without the Erberspacher the car would have been an igloo on wheels...

Back in the days when we had proper winters... They seem a thing of the past now...

[MattBLancs]

It's interesting, as I'm very unusually going to say something in favour of EGR:

I'm sure I've read the EGR cooler actually helps warm the coolant very effectively too. This DV6 doesn't have the cooler (just a straight length of pipe where it could have sat) but later ones do.

I think it is piped into the heater matrix hoses when fitted, which I guess suggests it would help bring the heater online sooner too.

(But generally I hate the cruk EGR chucks in the intake and think it's to the net detriment of a diesel engine)

[Huskyxantia]

Gosh Love that instruction That's a heck of a way to do it but I guess it saves removing the entire dash...

How well do you find the glowplug pre-heater works Matt?

Yes, it's a bit hard for my "mechanical sympathy" tendencies to tolerate, but a massive time saving, so worth a try.

I'm not sure if the video author 206's dashboard had been out previously (and by extension, was missing some fixings) or if the earlier ones (his was a DW10, which gave way to the DV6) were slightly less robust. But there's no way I could get enough flex by hand to get it out as shown! Foot in a strap worked really well though.


Glow plug heater thing - I'm pretty sure it does contribute meaningfully, I left it idling whilst squeezing hoses etc to encourage air out the system, then bit off faffing lubrication of the isofix seat base. Came to hoover the footwell of the rivet drilling fragments and there was meaningful warmth in the cabin. Very little load on the idling engine (headlamps and blower fan only) so guess a good proportion of the heat was the little glow plug thing doing its job.


Has anyone ever changed the plugs in one of these? Am sure I read XUD ones are different but might fit? Anyway, I'm not attempting it at present as seems is no need!

Glow plug change is best with & i guess your know engine head off as these little bosch ones do like to snap there weak ceramic tips ! If you do this with the engine in & one snaps you wont have room to drill them out. Forget all the blow the tip out with the engine running as thats almost fantasy it may of worked once but ....id say if the head gasket needs doing then do the glow plugs as well,head off easy to do, but im sure some one might jump on this post and say i did mine with the engine intact fair play if so ,when all the work was done on my 206cc someone was doing the head cleaning i was getting the glow plugs out and refitting new bosch ones 50 quid the set & copper greased the threads .

You really done a cracking job with your matrix matt . Well done.

[Huskyxantia]

My 206 has an egr cooler and its s DV6 but each year could have slight mods

[Huskyxantia]

And yes the cooler is in-line with the coolant system i think after the thermostat housing hence the water will be warmer glow plugs work with this setup i read somewhere

[MattBLancs]

Thanks, I was pleased to get it sorted!

Just to be clear, yes was talking about the little glow plugs on the heater "block" on the coolant line, it's bolted to a bracket on top of the gearbox. But equally bad news if shear off when attempting to remove them!
This DV6 has been out (as per my profile picture) = snapped glow plugs part of the reason it came out so those in the engine aren't something I would jump to replace readily!! all part of the learning curve.

They are quite a bit lower than the heater matrix connection, so hopefully unlikely to run dry - but can imagine that's a very hot thing indeed with 4 plugs in such close proximity! Jim's example must have made some funny (kettle!) Type noises I'd guess!

[Huskyxantia]

I see what you mean now , and ive learnt something new today aswell i wondered what these did , mine has this i think the nuts are covered with thick rubber caps, now i know what these are now im going to check them when weathers a bit warmer make sure the contacts are clean

[Huskyxantia]

Also makes you wonder if these could contribute toward an anti pollutant fault, not that I've got any. Just my brain seeing possible other none obvious causes

[MattBLancs]

I see what you mean now , and ive learnt something new today aswell i wondered what these did , mine has this i think the nuts are covered with thick rubber caps, now i know what these are now im going to check them when weathers a bit warmer make sure the contacts are clean

Yes, little rubber hats on them, the top is positive connection so wouldn't want that able to short onto anything else so rubber hats are important.

If going to be digging into clean contacts then I'd get multi meter on them - remove rubber caps, then 8mm nuts and the two "link bars" joining them up. Meter on ohms setting, one contact the stud on top, the other the aluminium block or bottom of glow plug nearest to the block.

About 1 ohm is healthy (mine read 1.2) and open circuit / infinity is obviously dead plug. Then at least you know if worth cleaning contacts or not.

The link bars are brass, surprisingly quick rub with wire wool had them gleaming again.

Also put each nut in an 8mm socket and ran the underside against a smooth file, cleaned that up too. Ring terminal on each wire with wire wool too, then reassemble.


I don't think would trigger a fault code (as a fairly "dumb" device, just feed it 12 volts and it'll get hot) so no signal to feed back. Could be sophisticated and monitor current I guess? They are fed in pairs which is odd. Wonder if two or four are switched on depending on temperature, heat demand? Interesting.

[Huskyxantia]

I know what i will be doing this weekend id of never thought of doing these i remember disconnecting them when all the big rebuild was done 2 yr ago and thinking wonder what these are for and i hope i put them back the correct way.