Is there a special trick to bleeding the coolant system on a 1.9 multijet?
I've done the cambelt, water pump, thermostat and can I heck as like get the heater to run warm

I've bled it through the radiator top nipple, the nipple on the water pipe.
There are no bleed screws on any of the heater pipes to the matrix.
I've squeezed, prodded, bled, cap off, cap on, run up to temp (car finally gets 3 to 4 bars on the temp gauge)

I've even dropped the coolant again, and run a hosepipe through the heater matrix which is all good.
The new thermostat is working but the radiator remains cold, I'm thinking the rad could be blocked.

The other thing I've found is the heater control when set at cold, turn the knob one click to 18 degrees and the motor makes a noise but makes no further noise when you turn the temp up more.

The heater pipes remain cold, the top hose gets hot at the thermostat but cold at the rad,
Coolant bled from the radiator is cold.

The heater has been only tepid since owning the car a few weeks.
The old thermostat was stuck open and had been bodged up, one of the heater pipes had some kind of hardened putty in it as the plastic pipe had been broken off and bodged up. See pics.

Update,
After a ten mile run, the radiator is now hot, and the heater pipes are slightly warmer but that may just be residual engine bay heat.
Water level is perfect, no sign of overheating. Fuel economy already improved as Is engine performance.
Just no bloody heat.
The temp hood steady at four bars no problem.

My multiscan stuff will be here tomorrow so I'll be able to see what's going on with the engine temp and finally reset the service light.

Have you got the two hoses that go onto the back of the 'stat the right way round?

I did wonder about this, they went back on as they came off. I did quickly try them the other way but it looked wrong and awkward that way round.
I just don't get why they don't have bleed screws like most other fiats there.
I had a spare set of coupe pipes and was tempted to fit one with a bleed screw in but typically couldn't find them

Since I've been looking at the two pictures of the new verses old thermostat, I've noticed that the two heater pipe connections are at different angles on the new one.





What do you think, maybe this is why the pipes seemed to fit the new one, but could be on the wrong way round?

What make and model is the new one?

It's a circoli, not sure of the model.
Today my multiecuscan pack arrived, I've reset the fault code's, sorted the annoying service light and monitored the engine coolant temp from cold to 91 degrees, felt the thermostat open etc.

Then after its cooled ice swapped the heater hoses around and repeated the whole thing again.
Every coolant pipe gets hot (when stat opens) including the rad but the heater pipes remain stone cold.

My next option is to try and modify the heater pipes to include bleed screws.

Put the front of the car on ramps, start the car(when cold), open the expansion bottle and rad vents completely. Switch off and leave like that over night. The air should work it's way out to the highest point.I always bleed my cars like this. Never had a problem.

Worth checking if you were sold a duff / incorrect part, like sirias, who had the same symptoms:

https://www.fiatforum.com/multipla/436438-thermostat.html

That's what I was thinking - wondering if there's some bad information floating around for suitable parts match for the Multipla

It's aroyal pain, I've never had such an issue with bleeding afoot air from a cooling system before, could well be an incorrect part.

Update on this.

I'd planned to take the thermostat off today and check it against the old one regarding the heater pipe .
However, I noticed the coolant was low and there was a strange coolant coloured spray on the fan shroud. It soared that the new thermostat had started leaking between the plastic housing into the housing (the rad house one).
On removal I found that the returning coolant from the heater matrix could not go anywhere as it was blocked off.
Like the housing had not been drilled before fitting the hose connector.
Ridiculous is not the word.
This had then been pressurising the front half of the housing and literally forcing the front off.

I've another new one coming from a different source tomorrow and I'll check it before I leave the store.

In the mean time I have managed to get the old one on despite it being broken in two using another hose betterment the broken parts.
The stat is stuck open, but the heater pipes still get warm. Just a lot of messing around due to bad parts.

I think that's exactly the same problem as sirias had with his. It definitely sounds like there's some false (i.e. wrong) information on the automatic parts selection facilities being offered by some sellers. Could do with some part numbers for the right part on here for folks to refer to.

Hi I had the same problem, it turned out to be a faulty stat, the matrix pipe on the back of the new stat inside was completely blocked off With metal I had threw my old stat so had nothing to compare, after about 8 weeks of driving too work in freezing temperatures I got an old one from a breaker took off the new one and different inside no metal over the hole where the pipe connects couldn't believe it I changed it twice the first new one had a leak on the main pipe back too the rad second new one would not let hot water to the matrix, I'm still waiting for my money back, sounds like the same crap parts ? When I got the old stat from the breakers yard you could see inside the clear difference, and hot water instantly but the car did sit at 4 bars, can laugh about it now, I think it was from euro parts, my mate has a garage he ordered my stats for me it took some convincing before he admitted the stats was faulty I'm trained in vehicle restoration and more than capable of car repairs, hope this helps


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Further update.

Picked up another new thermostat from euro car parts.

The new new one is the same brand as the original new one, but the new new one has a drilling to let the heater circuit work properly.

Maker / part number?

Is it a hole you could drill yourself, through the connection pipe ?
I ask that because I have a thermostat from euro car parts tucked away somewhere. I bought it ages ago, but the fault was elsewhere so I didn't fit it and I won't have the receipt.

chr1s said:

Is it a hole you could drill yourself, through the connection pipe ?
I ask that because I have a thermostat from euro car parts tucked away somewhere. I bought it ages ago, but the fault was elsewhere so I didn't fit it and I won't have the receipt.

Click to expand...

I've seen something similar on (non car) pressure diecast parts. There is a plug or pin to form the hole and if it is not a good fit with the core (main hollow part) a thin layer of alloy gets between them and seals the connection. Could be poor die design, wear, or the die parts not coming together properly. If it's the last, sometimes caused by dirt or debris, some parts off a die can be OK and others faulty.


Robert G8RPI.

Euro car parts and Car parts saver (same company) both list a thermostat for the Multipla JTD at a very good price (about £37 on ebay) which is comfortably less than elsewhere. Most others are asking around £50. However, neither lists the Fiat OEM part number in the item description, which is unusual for them. The Fiat p/n is 46790296 for cars built between '01 and '06. I think the JTD 105 may use a different 'stat; the same for the later (JTD120) models

You could check the part number on the box for the ECP item on the web (somewhere like Autopartoo) to see if it matches up with the Fiat p/n.

As g8rpi says, it could also be a manufacturing fault.