Cooloing problem, challenge for anyone who can help!

[geo010704]

Hi,
I have a mazda 1994 323 1.6 carby. overheating problem. fan would not kick in, changed the thermo switch,relay & fuse link to no avail, decided to wire the fan to a switch, when car is at idle with the fan on it will tick away nicely all day, when I drive for 5 - 10 mins the temp gauge starts to climb. I let it cool for a few mins then start it up again, leave it at idle & all is good again!! Until I drive it again. So the car runs absolutly fine, just so long as I dont drive it!

Any help would be greatly appreciated

I am fairly mechanically minded but not an actual mechanic.

[vgames33]

Deteriorated water pump fins or a clogged radiator would be my first guess. Maybe even a sticking thermostat. Leaky head gasket, improper valve/ignition timing, etc can also cause this, but you'd likely notice running issues.

[shorod]

I second the thoughts of restricted flow in the radiator or a worn water pump. You should also make sure the radiator fins are not packed full of debris.

-Rod

[gmtech1]

We had one in the shop a little while ago that the water pump impeller was loose and could be spun on the shaft while holding the pully end. So I guess thats a 3rd for the water pump? Or again as stated before, restriction in the radiator?

[shadows]

all above is good

going back to the beginning
lets assume your system was full of cooling fluid
you start it up, runs fine, you drive it and the temperature climbs

you let it cool down couple hours-
open the radiator cap-
fluid is where it should be- fluid is clean-

when you start it after it's cool- is there fluid movement-
as it warms and you are watching while someone is sitting watching the termp gauge- do you notice fluid movement in the radiator opening as the temp hits what is normal

[oldblu65]

Had a vehicle do the exact thing as you described . I tried all the things mentioned but nothing made a difference . There was a noticeable lack of power as well . The solution to the problem was replacing the catalytic convertor . That made all the difference in power as well as getting rid of the cooling issue . Not sure this is your problem but would be worth checking into - Good luck !

[534BC]

Originally Posted by geo010704

Hi,
I have a mazda 1994 323 1.6 carby. overheating problem. fan would not kick in, changed the thermo switch,relay & fuse link to no avail, decided to wire the fan to a switch, when car is at idle with the fan on it will tick away nicely all day, when I drive for 5 - 10 mins the temp gauge starts to climb. I let it cool for a few mins then start it up again, leave it at idle & all is good again!! Until I drive it again. So the car runs absolutly fine, just so long as I dont drive it!

Any help would be greatly appreciated

I am fairly mechanically minded but not an actual mechanic.

Maybe you can describe the "overheating" problem to us? From your description you have an overheating problem AND the fan doesn't come on? Do you have any temp numbers for us? Is this boiling over?

Just want to make sure it is actually overheating because many times some think it is hot and it is , but all is normal with temp and it just isn;t hot enough for fan to come on yet.