hi i have a 1998 fiat punto 1245cc sporting 16v and i have just noticed that when i drive my car normal the engine water temp is at a normal level however when i am in traffic or at traffic lights or idling i notice my temp gauge very slowly creeping up and then stops at the halfway point. i really am baffled because i know that if the temp gauge goes up past half way then i know that it could mean the head gasket is on its way. i might try to change the coolant in the car as ive had the car since 2008 and ive not changed it yet could this explain why. so any help would be appreciated
thanks.

Does the fan come on?

Actually shouldn't it be in the middle anyway? (never had a punto) In which case is it the thermostat constantly open?

The temp will rise if the car is sat there with the engine running. The needle will generally get halfway before the electric fan cuts in to cool things down. As you drive along, the air being forced over the rad fins will do a great cooling job.
The temp rising too high is indicative of fan failure (or associated electrics inc sensor) and / or stat failing.
HG failure is generally indicated by loss of oil and/or coolant rather than a rise in temps.

If you do find yourself in, say, a traffic jam & the fan isn't cutting in, a temporary 'fix' is to turn the heating to maximum and the blowers to max - OK, so it'll push loads of very hot air into the car but the action of the small fan over the heater matrix will help a great deal.

If you are thinking of renewing the coolant, turn the heater to full before draining the system & flush with plenty of water. Disconnect the rad & treat it as a separate item.
Might also be an idea to remove the stat, clean off any old gasket and test its operation in a jug of boiling water.

NORMAL is half way on guage. After half way then the fan should start to provide additional cooling.

From what you are saying I conclude the following:

1) Normal for you is the guage below half way point?
2) When stationary temp rises to half way (and fan cuts in?)
3) When you drive again temp falls quickly?

These are that characteristics of a themostat that has stuck open.

The way to test for NORMAL operation is simple.

a) leave car overnight to totally cool down
b) shut off/set to cold the cabin heater control
c) open bonnet and locate top and bottom radiator hoses
d) start engine and run at idle
e) hold top and bottom raditor hoses in each hand
f) over time the top radiator hose will slowly warm up until quite hot but the bottom raditor hose will remain very very much cooler
g) eventually the top rad hose will become very hot and very quickly the bottom radiator hose will get very much hottoer and quickly as the thermostat OPENS.

If you find that both top and bottom radiator hoses warm up together then this indicates a stuck open thermostat.

s130 said:

NORMAL is half way on guage. After half way then the fan should start to provide additional cooling.

From what you are saying I conclude the following:

1) Normal for you is the guage below half way point?
2) When stationary temp rises to half way (and fan cuts in?)
3) When you drive again temp falls quickly?

These are that characteristics of a themostat that has stuck open.

The way to test for NORMAL operation is simple.

a) leave car overnight to totally cool down
b) shut off/set to cold the cabin heater control
c) open bonnet and locate top and bottom radiator hoses
d) start engine and run at idle
e) hold top and bottom raditor hoses in each hand
f) over time the top radiator hose will slowly warm up until quite hot but the bottom raditor hose will remain very very much cooler
g) eventually the top rad hose will become very hot and very quickly the bottom radiator hose will get very much hottoer and quickly as the thermostat OPENS.

If you find that both top and bottom radiator hoses warm up together then this indicates a stuck open thermostat.

Click to expand...

good guide

s130 said:

NORMAL is half way on guage. After half way then the fan should start to provide additional cooling.

From what you are saying I conclude the following:

1) Normal for you is the guage below half way point?
2) When stationary temp rises to half way (and fan cuts in?)
3) When you drive again temp falls quickly?

These are that characteristics of a themostat that has stuck open.

The way to test for NORMAL operation is simple.

a) leave car overnight to totally cool down
b) shut off/set to cold the cabin heater control
c) open bonnet and locate top and bottom radiator hoses
d) start engine and run at idle
e) hold top and bottom raditor hoses in each hand
f) over time the top radiator hose will slowly warm up until quite hot but the bottom raditor hose will remain very very much cooler
g) eventually the top rad hose will become very hot and very quickly the bottom radiator hose will get very much hottoer and quickly as the thermostat OPENS.

If you find that both top and bottom radiator hoses warm up together then this indicates a stuck open thermostat.

Click to expand...

i have changed a faulty thermostat and antifreeze on my car and when testing, the bottom hose got hot first, and then the top one

problem?

heating works better than before, car warms up faster and temp gauge sits in the middle (it was always at 1/4 before the change) with the fan turning on when it goes a little over

The blue coolant is only good for 2 years. To my mind, stuck open thermostat. Check that the radiator fan comes on.

flisko said:

i have changed a faulty thermostat and antifreeze on my car and when testing, the bottom hose got hot first, and then the top one

problem?

heating works better than before, car warms up faster and temp gauge sits in the middle (it was always at 1/4 before the change) with the fan turning on when it goes a little over

Click to expand...

You have got me thinking now. Maybe I've got the top/bottom hose warming swopped over. I guess it all depends on the car and the water pumping direction. However hot water rises so that natural convection path is upwards so to pump downwards does not make much sense.

Anyway whichever way it goes it sounds like all is working OK again.

s130 said:

You have got me thinking now. Maybe I've got the top/bottom hose warming swopped over. I guess it all depends on the car and the water pumping direction. However hot water rises so that natural convection path is upwards so to pump downwards does not make much sense.

Anyway whichever way it goes it sounds like all is working OK again.

Click to expand...

bottom hose is the one connected to the water pump so it should probably get hot before the top one, cuz thermostat is still closed

:yeahthat: water doesn't flow through the rad until stat opens so top hose stays cold upto about 60 degrees then gets warm fast.

after i changed thermostat there is antifreeze leaking from the bottom of the radiator-before thermostat change it didnt leak, can that be cuz i filled it over the max mark

Not unless you radically filled it over the full mark.

Chances are -- especially if you've a worm type clamp -- that it just needs tightening or replacing. But get under there with some kitchen towel so you can be absolutely sure where it's leaking from.

fingers99 said:

Not unless you radically filled it over the full mark.

Chances are -- especially if you've a worm type clamp -- that it just needs tightening or replacing. But get under there with some kitchen towel so you can be absolutely sure where it's leaking from.

Click to expand...

overfilled tank-pressure caused the radiator to crack?

it leaks from there

Strange. I've got no explanation. Co-incidence? Rad weld flushed out?

fingers99 said:

Strange. I've got no explanation. Co-incidence? Rad weld flushed out?

Click to expand...

rad weld?

google it, its to temporarily fix small leaks - but general consensus is its bad stuff and should be avoided.

Are you 100% its not weeping from one of the pipe connections and just dripping from that area.?

was watching under the car, and leak comes from there for sure, maybe it is removing excess fluid

Think about it. It wouldn't happen from there -- there's no mechanism for doing that. The designed in "weak point" is the pressure cap.

Like I said, check that it really is from there -- kitchen towel (or talcum powder liberally puffed over area) is a good tell tale, but you really, really, need to look.

reading somewhere else that when i overfilled the tank there was so much more pressuse that it bursted out of the radiator on the weakest point

Well, radiator isn't the weakest point (or just about every HG failure would result in a blown radiator). Even where the cap fails to blow you'll generally see the expansion tank blow up first.

The water itself doesn't compress, just transfers the pressure from the system (air, steam, etc.). You'd really have to try hard to overfill the system to the point where that had an effect.

This looks like either a leak from the radiator itself, the water pump or water rail or water rail O ring (both of which can appear to be coming from that area) or a bad hose connection.

Best bet, remove anything which obstructs your view. With the car firmly supported, up to temperature and engine running, crawl under and take a good look.