ZX smells when heater turned on.

Dave1 · Unread post by **Dave1** » 06 Jun 2007, 13:26

I know, it immediatly suggests the matrix. I have read through many previous posts but here is the tale.

I have had this car many years and changed coolant every two years with original Citroen a/f.

Recently the radiator leaked at the bottom. I was alerted to this by the fact the car heated up to 90 degrees where fan comes on. This happens VERY rarely. It normally has to be a sweltering hot day and I am stuck in traffic etc. So I was surprised. I had to drive home and water will have been a little low. It was a cold outside ( car had stood 9 hours). The temp guage barely rose and and only luke warm air from heater. The next day I replaced the radiator draining the system and topping up with header tank as I always have.

All fine. The car runs well, settles at 80 degress or so but there does seem to be a tendancy for it to heat up faster from 80 to 90. Also there is a/f around the bay from the rad overflow. I have run the engine from cold and checked the thermostat is opening at the correct temp by holding the hose to the rad.

The a/f is as clear as when put it in. There are just the 3 issues as far as I can see.
1) the smell of a/f when heater on
2) nominal amount of a/f blown around the offside wing (not had to top up in the month since I did it but settles low and rises when warm)
3) my feeling it has a propensity to head towards 90 degress when stood.

I will bleed system again but have th head gasket / matrix converns now. I may also try a new rad cap.

Any ideas about this scenario

Oops, forgot to say this is a TD version (Volcane).

Unread post by **RichardW** » 06 Jun 2007, 15:35

If you can smell AF in the car then odds on the matrix has gone. Dash out time I'm afraid. Threre's a possibility that you can jsut smell the AF it is losing under the bonnet, but check this by running it up to temp with the heater off, then turning on - being greeted with the AF smell confirms matrix failure.

You might have a HG problem also - check if the system is pressurised when cold, then start and run it for 1 min from cold and check for system pressure, then look in the header tank engine running for bubbles (not that easy on a ZX TD as there is little flow pipe in the header tank that disturbs everything. If the answer is yes to any of the above then you will get easy access to the matrix engine bay side connections whilst the head is off.....

Unread post by **CitroJim** » 06 Jun 2007, 16:41

I'd concur with Richard unfortunately

Strangely though, my old TD has given a little whiff of antifreeze smell every time the heater is moved to hot if it has been on cold for any length of time. It has done this for over two years now (since I've had it in fact) and yet it uses no coolant. My Activa does the same thing. The smell is very brief and never returns so long as the heater is off the cold setting.

I guess both matrixes are just beginning to weep a little

Big jobs looming one day on both I guess

micitroen · Unread post by **micitroen** » 06 Jun 2007, 17:57

If it is only the slightest whiff and the H/G test as suggested proves negative then its worth trying a bottle of Barrs leaks.....I wouldn't suggest anything stronger (don't ask)

but I've used it with good results. It doesn't seem to 'clog up' the rest of the system like some of the other stuff does.

Unread post by **CitroJim** » 06 Jun 2007, 18:36

Hi Mike,

Thanks, a bit of Barrs is well worth a try. Anything to delay that inevitable time when the dash must come out

I recall a post on here saying that it was recommended a dose of sealant be put in with the coolant when a new matrix is fitted.

I've had two new matrixes in my 205 let go in a big way during my ownership

I determined that both failed on the "U" bends in the tubes at each end. They are made of very thin aluminium and in my case they were abraded away on the tightest part of the bends due to the presence of residual silt and scale in the system acting like grinding paste. This was following a period of use (by the previous owner) of plain water which in turn wrecked the original engine. The majority of the residual scale was found in the expansion bottle

Shows the value and necessity of regularly changing the coolant!

Dave1 · Unread post by **Dave1** » 06 Jun 2007, 19:27

Thanks for the replies, as you will see I have added the model now, don't know why I did not in the first place but was rushing a bit during dinner.

The smell does only appear when I turn the heater on, fine when cold, did 160 miles yesterday without issue other than the water blow out a little from the rad overflow. I have found in the past it always settles mid way down the chamber eventually in anycase.

I did try the HG test this morning, losened rad cap and then replaced it. Ran engine for 30-40 seconds. Then losened the cap. There was a slight release

, nothing major though. How much should cause concern or is it just any amount

I almost bought Barr Leaks yesterday at Halfrauds but hestiate to introduce something into the system for short term gain. I will always be niggled by the faulty matrix.

I have this afternoon topped up the water whilst bleeding the matrix and thermostat parts. No air appears to be anywhere at this time anyway. I have also put on the new rad cap but this is merely a precaution anyway, do not expect it to solve the issue. Be nice it it was ok tomorrow though.

jeremy · Unread post by **jeremy** » 06 Jun 2007, 20:39

How high are you filling the radiator? If you have the radiator with the filler on the off side - the low level mark is about 1 ft down the tank behind a small pipe - and the full mark is about 4 inches down. If it overfilled the surplus will be blown out. The marks can be seen if you shine a torch down the filler in the dark (providing the tank is empty). They are shown in the owners manual.

Dave1 · Unread post by **Dave1** » 06 Jun 2007, 21:41

jeremy wrote:How high are you filling the radiator? If you have the radiator with the filler on the off side - the low level mark is about 1 ft down the tank behind a small pipe - and the full mark is about 4 inches down. If it overfilled the surplus will be blown out. The marks can be seen if you shine a torch down the filler in the dark (providing the tank is empty). They are shown in the owners manual.

When I fill the radiator I use the "makeshift" header tank method to ensure there is sufficient water to allow the bleed screws to "bleed". This invariably does fill the radiator to the top but then I syphon some out taking the level below the MAX mark which can be felt and seen on the radiator. Further down the MIN mark can be seen.

Worth suggesting though.

weety · Unread post by **weety** » 06 Jun 2007, 23:22

my old xantia had a matrix leak (to the extent that when you put the fans on the car started to fill up with funny smelling fog)

i couldnt face doing a matrix so i chucked in some rad weld and it worked! i expected a blocked up matrix but it cured the leak and i still had heat inside the car........

car did about 30k miles after that before i was finally forced to scrap it at 266k (cos just about everything was knackered)

cant see you have a lot to use trying radweld on a heater matrix, if it doesnt work or works to well (blocks the matrix) you are no worse of than when you started....

Dave1 · Unread post by **Dave1** » 07 Jun 2007, 20:11

That's exaclty the conclusion I came to this morning. So the Bars Leaks went in at dinner time before a drive. I have not checked for a result yet, heater off all the way. May try later tonight. Typically, how long does it take anyway?

weety · Unread post by **weety** » 07 Jun 2007, 20:23

not long at all.....if its going to seal it its gonna do it fast

jeremy · Unread post by **jeremy** » 07 Jun 2007, 20:46

It doesn't make any difference if you turn a ZX heater on or off as it hasn't got a water valve. Its an air-blender which means that the matrix is hot all the time and the control is by flaps.

Dave1 · Unread post by **Dave1** » 07 Jun 2007, 21:09

jeremy wrote:It doesn't make any difference if you turn a ZX heater on or off as it hasn't got a water valve. Its an air-blender which means that the matrix is hot all the time and the control is by flaps.

It does to me because I do not have to smell it on cold.