Peugeot 405 1.9TD losing water

I have a high mileage 405, 1.9TD. Recently, I noticed steam coming from the
offside front of the car, although the temperature guage read normal. I had
been driving for around 20 mins on a dual carriageway when I hit slow
moving traffic and noticed the steam after a few minutes. I called out the
AA, who diagnosed a stuck thermostat. However, I have now replaced it but
still have the problem.
After driving the car and then stopping the engine, I can see a slight
amount of water bubbling out of the radiator cap. As it runs down the
expation bottle, it hits the hot radiator and then steams off. I think
that this was the cause of the original steam I noticed in the traffic
jam. Additionally, after the engine has cooled, there is still some (but
not much) pressure in the cooling system and, upon removing the radiator
cap, a small amount of water is occasionally lost on releasing the
pressure.
Why would I be losing water through the radiator cap? It is not a great
amount-about 1 pint a week (300miles). Could it be the head gasket? My car
has otherwise had 224k trouble free miles!

 

Could just be that the rubber seal inside the radiator cap has
perished, try putting a new one in and see if it stops leaking. I've
seen a thread somewhere on here which said you can even make a
perfectly good one out of an old bike inner tube, if you are so
inclined.

HTH
Andy J

 

When the last engine on my 205 Diesel started dying it messed up the
water pressure. This caused the expansion tank to overflow and the
radiator to bust spectacularly in about 20 places eventually. I tried
measures to stop it, like Halford radiator sealant but it just kept
springing more leaks.

Previous to this the coolant would need topping up every few months,
something you don’t have to do on a healthy Diesel.

Eventually the engine stopped starting properly without being rocked
and when the engine was inspected three days after the beginning of
the starting problems, flecks of Metal were in the emulsified oil.

I don’t know if you can do this on the 405 but to check the health of
a 205 diesel (which has an almost identical engine) you take the cap
off the expansion tank and start the engine. If vapour (exhaust) comes
out of the coolant then you have damage in your engine (cracks, warped
gaskets etc).

Personally if this test proves true, I’d book the engine in for
replacement with a reconditioned unit, or get yours rebuilt.

 

Many thanks for your replies.

I have tried replacing the radiator cap which reduces the water loss
considerably. I have also found that after running the car for about 20
miles to work, when I return to the car some 8 hours later and remove the
radiator cap, water is forced out under pressure even though the engine is
obviously cold by this time.

I have also tried running the engine with the radiator cap off and water
level to the max mark, no vapour comes out but, after a short time, the
water overflows the filler cap.

Has anyone any further ideas or does this confirm a head gasket problem?

Many thanks,

Clive.

 

If its a head gasket problem there will probably be oil in the cooling
system.

JG

 

I have a 1992 405 1.8TD and I lose water too, maybe a cupful every few
hundred miles and this has been going on for 40,000 miles. I would first
suspect the radiator cap and fix that. Second I've noticed that if I
fill the rad only to the marker deep inside I lose less water - there is
a little hole in the side of the rad neck just below the rad cap which I
take to be some sort of pressure regulator - too much water and water
flows out here. Sound familiar? Third (which may not apply in your case)
I'd check the pressure filer hole on the off-side of the rad. This has
an o-ring which hardens and leaks after many years. Fourth I'd check the
joint by the side of the heater matrix under the glove box ... this has
two o-rings and also leaks - if a lot it's wet carpets, but if a little
is just mists the inside of the windows and smells of anti-freeze. Only
then would I seriously worry about head gasket, and only if losing a lot
of water. A search here will show it's a common worry, and it happened

 

Sounds like you have a head gasket blowing. Water will only get into the oil
if there is a failure of the gasket providing this path. In your case sounds
like a failure between a cylinder and a water way. You should be getting
white smoke and probably water out of the exhaust. There is a snuffer that
can be used on the radiator cap when the engine is running to detect
combustion products i.e. damaged water way to cylinder gasket leak.
Mike

 

Thanks again for your ideas. I don't get any noticable oil in the water. I
have tried draining some coolant into a container but cannot see a film or
rainbow effect in the water.
I had been losing a minimal amount of water for years - I had to top up
every 4000 miles or so, certainly nothing to worry about. There is no
dampness, anti-freeze smell or misting up inside the car.
I have noticed that, since fitting a new radiator cap, I lose less water,
but after the engine cools, the cooling system remains under pressure. If
I release this pressure using the 2 vents, on the radiator and the small
hose near the thermostat (air escapes from both), I can then remove the
radiator cap to see the water level right up to the brim of the expansion
bottle filler neck, even though I had not originally filled it to this
extent. (If I do not release the pressure prior to removing the radiator
cap, I get covered in coolant). I therefore assume that there is now air
in the system which is displacing the water, giving the appearance that
the radiator has filled up whilst I have been driving!
Many thanks for your help and advice so far.
Clive.

 

The french in there infinate wisdom built the 405 with dodgy coolant
system. There are parts of the coolant system that are higher then the
radiator filler hole When you fill your car up you have to make sure
you use a header tank and bleed the system carefully. Failure to use a
header tank and bleed properly will lead to air locks and these airlock
can destroy the engine. I am also led to believe they can give symptoms
you describe. Never encounted my them myself but i always use a header
to refill.
Have a look on http://www.andyspares.com/discussionforum/default.asp
i use it and there is loads of hints/ tips and how to's on bleeding the
405 engines plus more.

hth
si

 

Thanks, Caveman. My system has a bleed valve at the highest visible point
of the cooling system, which I always use when I refil the rad. What is
suspicious is that every time the engine cools, I loosen that bleed valve
and, without exception, air is always released prior to water being
expelled. In other words, it seems to me that air is being sucked or
forced into the cooling system every time I drive and accumulates at the
highest point (obviously) until I release it again.
I have had a suggestion that the block or head may be cracked. Is this
likely, given the symptoms?
Thanks again for all your help,
Clive.

 

Hi again! I've visited the site Caveman suggested - it does certainly cover
a lot of topics.
I saw mentioned on there about a compression test. I know how to do this
on a petrol engine but a diesel has no spark plugs to give access to a
compression tester. I can only think that the glow plugs would be removed
instead but, they are in such an awkward position that getting to them is
an art in itself, let alone attaching a compression tester to the vacant
hole.
Does anybody know how to compression test a Peugeot 405 1.9 turbo diesel
engine?
Thanks,
Clive.