over heating

[moppetsdad]

Hi All

I have 1997 1.6ltr felicia and about 3 weeks ago it boiled up due to the themostat housing breaking, anyway since then I have replaced the themostat housing, thermostat which has been tested and is ok, the sender in the rad,the expansion tank cap, the water pump, the hoses seem ok , I have also had a sniffer test done and that was ok , it's not loseing any water , there is no mayo in the rocker cover,but the little rascal is still getting to hot!

When running the engine in the drive it gets to about halfway between half and three quarters and then the fan cuts in which is ok but when I drive it up the road the temp goes right up to just under the red and the bottom hose is no where as hot as the top hose but if I squeeze it a few times the hose gets hot, so I am running out off ideas now !!

Any suggetions would more than well received

David

[Groundzer0]

Not teaching you to suck eggs but have you go the correct thermostat? You said you have tested it, how? Can you be sure that it is opening at the correct temp?

[moppetsdad]

Hi GroundzerO

Ta for the reply I tested it in a pan of water on the cooker with a thermometer and it started opening at 85c and opened fully at 104c.

I have back flushed the rad this morning and the block and just been for a thrash up the road and it seems ok now, fingers crossed

[harryhill]

Sounds to me like you have an airlock in the system. I am not sure about the 1.6 but on the 1.3 the procedure is to remove the temprenture sensor situated on the thermostat housing when filling.

I have had this problem with a rover 214 and it just took lots of bleeding to get it right. Is there a bleed screw on the 1.6 as if there is the procudure would be to get some protective gloves (for boiling water) and when the car is up to running temp leave it running and open the screw till water is running out.

Another problem (hopefully not though) could be with the water pump being knackered and not pumping water round as it should. On some cars this is a major problem in the plastic blades breaking up. Others who have a 1.6 will be able to advise if this is a problem on the vw unit.

[pinkskud]

this prob is common on the 1.6 (well it happened to me). the housing went on mine so i replaced it, but after it didn't seem to want to hold a steady temp. and i had the cold pipe prob to.

when mine got to hot i just pulled over and gave the pipes abit of a pump and all was good. i had to do this about 5 times. now 1000 miles after changing the housing, it holds dead on the center line all the time.

[richardsfavorit]

Mine plays havok at the mo - though by the sounds of it I should try what you guys have. I have been using the heater to bring the temp down to normal, on a flat road its fine, but give it a hill / towing anything etc it just warms up. Was going to try changing the thermostat again - but I will try pumping the hoses first as pinkskud said.

[KenONeill]

All classic signs of, and methods for dealing with, airlocks.

[Fionnion]

Would the aforementioned airlock, affect the cooling fans performance on a 1.3MPi for instance? If so then I have a similar malady.

[Tech1e]

Yes because if you have an airlock you dont have water circulation.

I dont nomally have a problem, I usually just run the up and keep topping up until the thermostat opens and then put the cap on.

[daverapid]

Worth remembering that unlike most cars of it's age the Felicia has a water valve for the heater, therefore make sure you have the heater control set to HOT when re-filling and bleeding the cooling system. If you don't you'll have airlocks in the heater matrix.

[anewman]

Also heat issues can be caused by fans not working (thermostat on radiator or fan motor itself) but these problems are easy to notice and diagnose.

[BigW]

Hi GroundzerO

Ta for the reply I tested it in a pan of water on the cooker with a thermometer and it started opening at 85c and opened fully at 104c.

I have back flushed the rad this morning and the block and just been for a thrash up the road and it seems ok now, fingers crossed

How did you manage to heat the water in a pan to 104oC? :P

[Glider]

How did you manage to heat the water in a pan to 104oC? :P

You need to open your thermodynamics book

[BigW]

You need to open your thermodynamics book

Thats closed forever now , Just passed the exam :P

[Fionnion]

Also heat issues can be caused by fans not working (thermostat on radiator or fan motor itself) but these problems are easy to notice and diagnose.

Yes but my cooling fan ain't working, that's why i was wondering would a possible airlock be preventing the thermistor from gettign hot enough. iNcidentally, does anyone know how to test a thermistor. i have a multimeter, but what setting would I use?

[anewman]

Yes but my cooling fan ain't working, that's why i was wondering would a possible airlock be preventing the thermistor from gettign hot enough. iNcidentally, does anyone know how to test a thermistor. i have a multimeter, but what setting would I use?

First try joining the 2 wires together with the ignition key in and turned. If the fan works the fan switch is suspect.

Haynes says measure in pan of boiling water with a thermometer. I think you need to use the Ohm's setting and I think you're looking for resistance less than 210 ohms. I think basically if the reading changes substantially during temperature increase it should be working. I personally just renewed the switch, it worked again, I threw the old switch in the bin and never tested it

Other options include leaving the fan continually on, or putting a switch in the dash so you can do it manually.

[KenONeill]

Yes but my cooling fan ain't working, that's why i was wondering would a possible airlock be preventing the thermistor from gettign hot enough. iNcidentally, does anyone know how to test a thermistor. i have a multimeter, but what setting would I use?

If an airlock stops the thermistor working, you've managed to get an airlock in the top of the radiator. This was impossible with old integral header rads. With a modern remote header unit, there should be a bleed point on the radiator top (if the remote header isn't sited such that opening it bleeds air out of the radiator), so park on level ground and let the engine get cold, then bleed as little as you can out of it. basically stop as soon as you get water.