Heater Matrix

[chrismac]

I've been having problems with the cabin heater, It only gets luke warm, the needle gets to and is stable at 90 degrees. No loss of coolant, car runs normally.

I have bled the system twice, but still no heat.

I decided to put the car into a Peugeot dealer for a proper diagnosis, so now £160 lighter I have been informed that the heater matrix needs replacing. Main dealer price for parts and labour......£1100.

After picking myself up off the ground I decided that I would refuse their kind offer.

I'm going to flush the internal matrix (without removing it from the car), Plenty of videos on Youtube and see if that helps.

If that doesn't work I will get an aftermarket matrix on Autodoc, a damn site cheaper than the £400 official Peugeot part.

If anyone has any other suggestions, advice or well meaning comments I would appreciate them.

TIA

 

[rczpali]

Have you confirmed that there is coolant flowing into the matrix ... ? Join inlet and outlet from thermostat with clear tube to see if issue isn't thermostat?
And yes maybe flush matrix whilst you have disconnected

 

[rczpali]

I had similar issues after my saga with loosing coolant ... , root cause was the thermostat... Pig to work on ... after replacing thermostat..I found cabin warm but not hot ...only.by using a pressure test kit around £45 on Amazon to add 15 psi to the cooling system did I start to resolve issues , and as car not running or coolant hot safe to then opening up the bleed screw in the thermostat...pipework and work around engine And keep pressure on .. I found more effective bleed ... .could be worth trying too

 

[rczpali]

Did Peugeot confirm, supply with their diagnosis any report ... Confirm what they tested and tried or did they just say it needs a new matrix ?

My experience of Peugeot main dealers is they don't know as much as they should ..and are just menu pricing , swapping parts or can't really be bothered . This is just my opinion .. I'm sure there are good main dealers .agree £1100 not worth it .

Hope you get this resolved soon.. all the best and good luck .

 

[Pedro]

Old trick from a 70 yrs old Git when the engine is hot feel the bottom hose if its coldish its the thermostat as this issue can knock out the Aircon !

 

[chrismac]

Thanks Pedro, Will try tomorrow if it ever stops raining.

I have just noticed there was no diagnostic report attached to the invoice,

RCZPali - You could have a point here. If Peugeot are wrong and its not the Matrix, I have no comeback if its not broken !

 

[EddieJ]

My money is on the heater matrix (so long as there is no coolant loss, and the car is steady 90deg) as the heater matrix is badly positioned in them, near a 45deg angle and the way they are connected into the water system the coolant is not pushed, basically just using the heat rises theory. Any particles going through the engine like to settle in it. As such they can sludge up from the lower section of the matrix. You can get your hand to the pipes going into the matrix in the engine bay, they should be close to the same temperature once the engine is fully hot. If they are way different get a couple of bits of hose and add them to the matrix stubs to help you get your rad flush in, let it sit a good length of time, blow through with a garden hose, gradually increasing the pressure so as not to pop the matrix. repeat a few times until you stop getting muck out. Unless the matrix is leaking, it will flush through with the right additive. Last I did it took several goes to start getting a trickle coming out under water tap pressure before it started flowing good and clean. You’ll be surprised what you see coming out, nearly worth doing every few years as a separate thing along with an engine coolant flush. Rem the muck that built up up went in from the hot side, so you want to push it back out from the cold side so as not to send it further into the cores.

Words of caution, the pipes are push on with a push in tab to release, they are old and can be a touch brittle, make sure the release tab is fully push and pull off straight.