Technical How hot....

[wull85]

The in-law has gave me his Seicento to run about in and sort a few issues and one thing that I've noticed is it never really heats up,I get Luke warm air from the blower which leads me to suspect a faulty thermostat.

What's the blower like in your motor? How hot does it get?

 

[Jd801]

I get Luke warm on cold setting and fairly hot on hot.
Make sure the cable hasn't broke between switch and heater box and also make sure there is no air in the coolant system

 

[wull85]

I've not bled the system yet but I'm fairly certain the cable is working as when I select cold etc the Luke warm air becomes purely cold.

How easy is it to remove the heater control panel?

I removed the two Allen screws but it was still attached solidly,and as its not my car I didn't want to use excessive force and break it.

 

[fingers99]

I'd suspect faulty stat (stuck open) or that someone has bled the system without turning the heater on to full.

Which isn't to rule out the above, but it's not something I've ever come across.

 

[wull85]

I'm thinking for the sake of a tenner I'll just order the stat and swap them over and take it from there.

I've got the car at work with me today so I'll just quickly double check the above to see if it makes a difference.

I'll start the car from cold and check the coolant hoses that come from the stat,I'm suspecting that of they feel all the same,from the stat to the rad,and from the rad then surely that'll indicate that its stuck open.

If the stat is suppose to open at 87 then the hose from the stat should be quite warm.


Cheers

 

[David C]

My Cinq heater gets proper hot.
The Sei have a coolant valve on the heater though to control the coolant flow through the heater.
Could be that valve
Or the thermostat
Or wasn't bled with the heater on hot (as mentioned above).

 

[Frosty1961]

I've not bled the system yet but I'm fairly certain the cable is working as when I select cold etc the Luke warm air becomes purely cold.

How easy is it to remove the heater control panel?

I removed the two Allen screws but it was still attached solidly,and as its not my car I didn't want to use excessive force and break it.

There is a small star screw hidden behind the blower speed knob, pull off the knob and undo the screw along with the allen screws you've already found and the panel pulls off easy enough..I doubt the problem lies that end though..more likely the stat is faulty or has been removed..Bleeding the system as mentioned wont do any harm either

 

[wull85]

Right I was fairly convinced the thermostat was gubbed,and with it only costing a tenner I thought "bugger it" and ordered it today whilst on my dinner break.

Now after work I drove the car home (40 miles) and decided to check the relevant hoses.

I checked

Hose from thermostat to radiator (top hose) : absolutely roasting

Bottom hose from radiator to water pump : hot,not as hot but still hot.

Two hoses disappearing in to the bulkhead to heater matrix : roasting

So wtf???

Sounds like this valve at the matrix needs looked at,so why I never checked them hoses first I'll never know but now I've got a spare thermostat that I don't need,for a car that ain't mine haha.

Any ideas

 

[blu73]

first thing to try is bleeding it properly, could be air locked.

pipe temps sound right to me, water flows out of the head through the top rad hose and out the bottom so heat has been lost via the rad and the bottom hose should be cooler than the top.

If you are going to change the stat then replace it with a genuine item, so from fiat or partsworld.co.uk sell genuine stats. Had cheap unbranded white boxed items even from alot of reputable parts suppliers of late. Only real way of testing the stat without taking it off the car (and its not fool proof) is to start the car and let it warm up , hold the top rad hose and it shouldn't get gradually hot - it should stay pretty cold and then suddenly get hot when the stat opens, circa 60 degrees celsius. If the hose slowly warms up with the engine temp then either the stat is stuck open or even had its internals removed (more common than you would expect). And as said already, bleed with the heater turned to full hot once swapped.

 

[wull85]

I've not looked at this again yet,I've still to take the panel off to check that it works fine at that end,then I'll bleed the system.

Failing that I'll fit the new stat when it arrives.

I'm fairly certain the top pipe gets gradually hot though,from start up it gets warmish soon after which like was mentioned above made me believe the stat was at fault. That's why I ordered one.

Cheers