Technical Panda Mk3 Cabin Heater Malfunction

[revrob]

Good afternoon,

Daughter has a 2012 (but Mk3!) Penda, 1.2 8v.
Basic model with nor aircon.
Cabin blower is working, but the heating function is not.

Would welcome advice as where to start, please?

Very many thanks,

Robert

 

[varesecrazy]

Hi

1, check the coolant level

2, check the 2 x pipes going from engine into firewall get HOT

Let us know what you find

 

[revrob]

Thanks. Apologies, but what is the firewall?

 

[koalar]

Thanks. Apologies, but what is the firewall?

The pipe ringed in red

 

[varesecrazy]

Firewall : bulkhead..

Between Enginebay and Passenger compartment

The 2 s smooth hoses feed the Heater element within the dashboard

Its basically a small radiator.. and air flows over it to get warm air

So problems would be..

Impaired airflow.. or Coolant flow



Is this a vehicle you had last winter... the heater is known to work..??

 

[revrob]

Yes, car has been with us for over 3 years. Not had this problem before. Daughter doesn’t do many miles, and the heater has not been on recently due to the nice weather. Car was serviced and MOT’d a month ago, and I asked them to change to coolant ……

 

[varesecrazy]

If the coolant level has dropped.. its very likely youve got an airlock... so no coolant flow to the heater


But 1st.. check the coolant level

Shining a torch down one side of the sight tube will highlight the actual level easily

 

[revrob]

Thank you all. Still trying to get hold of daughter. *IF* it is an airlock, what’s the remedy?

 

[koalar]

The later 69hp engines self bleed okay if everything is working fine
You just need to keep everything topped up when the engine is up to temperature and the thermostat has opened

I would put money on the coolant level is low and below the heater matrix level so there is no flow of coolant through the heater

Official procedure

0010T20 ENGINE COOLANT - CHANGE - Fiat - NUOVA 500 - eLearn - 4CarData

After I did a full coolant swap I didn’t need to open any bleed screws, just kept it fully topped up and it self bleed fine

 

[koalar]

It’s almost impossible to see the coolant level in daylight

Shine a torch on the side at night works

If it’s at the max you can just see the surface down the opening with a torch


If you are unsure how much is in, it’s as easy just to top it up


It’s important that it isn’t over filled. There needs to be an air to allow for expansion

You can either burp some out by squeezing the large hose or open the bleed screw on the pipe I circled earlier. Be careful with the bleed screw it’s very delicate

 

[revrob]

OK, so coolant level was low. Put a litre in. Ran the engine for a while and went for a spin. Blower and heater full on, and lo and behold warm air came through. Have asked her to monitor the levels going forward. Thank you for all your help, I’ve learned a lot - I may well be back!
Many thanks,
Robert

 

[jrkitching]

I would put money on the coolant level is low and below the heater matrix level so there is no flow of coolant through the heater

So would I. The cooling system is notorious for being difficult to fill after draining. Even with the bleeds open, on the first fill, I rarely get back as much as came out.

The system will self bleed over a few warmup cycles providing you top it up to the max line each time the engine cools down, preferably after standing overnight. As has been said, don't be tempted to overfill it; it won't bleed any faster and the excess will likely just be blown off once the engine is warm.

After draining and refilling, it's extremely important to keep checking the coolant level (with the engine cold) until the level stabilises. These engines are notorious for HG failure if run with insufficient coolant; failure of the heater to deliver warm air is the classic sign that the level is dangerously low.

 

[koalar]

OK, so coolant level was low. Put a litre in.

There’s only 4.6L so percentage wise it’s a fair bit

As has been said, don't be tempted to overfill it; it won't bleed any faster and the excess will likely just be blown off once the engine is warm.

If you are lucky it comes out the cap. But I have seen more than a few times it over pressurises the system and finds a week point. On the panda it’s normally the joint on the heater matrix

After draining and refilling, it's extremely important to keep checking the coolant level (with the engine cold) until the level stabilises.

Correct, now it’s topped up we/you will have to keep a daily eye on it for the next few weeks. (Torch at night)

Most garages use something like

Snap-on Store

shop.snapon.com

Which makes it almost impossible to get wrong

Could be coincidence that it was noticed the first time the heater were used after a garage visit. Somehow I doubt it

 

[DaveMcT]

I recently replaced the steel water pump suction pipe on our 1.2/60. An easy enough job, but bleeding the coolant was a nightmare. I ended up with a large bore rubber hose pushed onto the heater hose bleed screw fitting and a funnel on top. I squeezed the rad bottom hoses until the heater vent stopped gurgling. It was a bit messy pulling off the hose and popping the bleed screw back in, but it solved the problem.

 

[Yolanda]

If the coolant level has dropped.. its very likely youve got an airlock... so no coolant flow to the heater


But 1st.. check the coolant level

Shining a torch down one side of the sight tube will highlight the actual level easily

I remove the cap and shine the torch into the neck and even in daylight can easily see the water level.

 

[varesecrazy]

I found the other day that is also the case on my 2018 500

But its not been that easy on the other FIRE motor radiators.. ( maybe the angle of the 'neck' was @30' on all those old puntos)
wheras the 'chinese lantern' is pretty much guaranteed

 

[koalar]

I remove the cap and shine the torch into the neck and even in daylight can easily see the water level.

I can do this on my eco just

Previous panda had a baffle at the top and would only be visible if over the max mark which isn’t a good idea

Different year or radiator manufacture I can’t say. One of my old pandas was a replacement radiator anyway