Coolant getting hot while driving in traffic.

[Alecossy]

I'm not sure whether this is a mechanical fault or an electric one, so feel free to move the post if you feel like another section is more appropriate..Anyway, let's cut to the chase:

I got my cc only a few weeks ago and as soon as I drove it home, I noticed it would overheat (car's a 2002 1.6 petrol as per signature) Indicator would be in the red, stop sign would start blinking and the on-board computer would tell me to stop.
Brought it back the next day, mechanic took a look at it and decided to change the thermostat, timing belt, water pump, clean out the radiators and check that the fan would come on at the right time.
After a few days to sort the problem out, I got the car back and, while driving outside of town (I live outside of a major city) and on the highway it would stay nice and chilly at roughly 80°.
Today I had to run a few errands in the city and got stuck in traffic... I noticed the temperature would reach 90, stabilize and then slowly start to rise. Fan would come on at around 100° and keep the whole thing in check. Temperature would stop rising but not go any lower than 95 (half way between the 90 and 100 mark).
As traffic worsened, the situation did the same. Temp would reach high peaks at 110/115 (last mark before the red ones).
The indicator never really reached the red area and oil temperature would stay not far beyond 90. As soon as I got out of the city area and on the highway and started getting some speed, the temperature got back to 90ish.

I took some time to check the coolant levels and they seem to be okay, there's no obvious leakage and the liquid doesn't seem to be boiling... The hood and engine were obviously hot to the touch but i'm not sure whether it was 90ish hot or 120ish hot

I'd also like to add that I was driving with my roof open (it was a nice and sunny day with roughly 26° outside) and the AC was off, even though a weak stream of warm air would seem to come out of the vents...
I was driving sportively, maybe waiting a bit longer to shift gears than I'd usually do, but I don't think that could be the cause for such a massive overheating... I'd take it back to the garage, but I got the feeling they'd just change more parts and charge me more (the little adventure with the water pump costed me roughly 200 £, as the warranty would only cover what they call "lubricated parts" and since I had just gotten the car from them they decided to cover half of the expenses) so I'd like to hear your opinions first..

[Capncol]

Firstly I would check if it is actually overheating. You can verify this with a thermometer. I use an infrared one. It may well be gauge error.

[Alecossy]

Thanks for the quick and exhaustive answer... I got some updates, though... tonight I went out and drove through the city.. If the temperature actually gets to the last mark, the second speed of the fan kicks in and brings it back to roughly 100 C... Don't know if it's true but I was told that this particular car has a two speeds fan, one kicking in at around 95 and that is supposed to keep the temperature in check and a backup one which starts at around 110 and prevents the temperature from reaching critical levels... Does any of this make any sense? The indicator won't reach the red zone, so I'm a little less worried...

[Alecossy]

Didn't have the time to update this post, but I solved the problem.
Purely out of curiosity, I checked the air flow to the radiator and found out the fan was sucking in hot air from the engine and pushing it to the radiator and out of the car rather than getting fresh air from outside.
Apparently the previous owner had the fan refitted and the guy who did the job (clearly a professional, judging by the quality of the wiring) inverted the power cables. Fan was running backward. Removed the front grid, got to the panel behind the fan itself, switched them back, car won't get above 98 °C even in traffic. Thanks for the help!

[GrandadMonkey]

Well done on finding that one out. Never heard of that one before!

[gazza82]

Wasn't that professional then ;-)

[smokey]

Umm think this could solve my problem, any chance of a pic of the wiring to see if mine is the same?

[Alecossy]

@Smokey, haven't checked the forum in a while, couple of business trips to Paris and Christmas preparations kinda kept me away from my PC. I could try getting a picture next time I have some free time, but in any case just start your car, get in front of the vehicle and put a hand on the front air intake grid. If you feel air being pushed out (it feels like a light warm breeze), then it's possible your fan is spinning the wrong way.

If that's the case, you can follow the wire that comes out of your fan. It will first lead you to a small box near the fuses and then to a small black box located behind the fan itself. You might need to remove the plastic band that is on top of the bumper (its real name currently escapes me) but the bumper itself or the fan do not need to be removed.
As far as the connector goes.. It will be squared and have two wires going in. You'll easily recognize it as the two wires are massive compared to the others that you'll have around you. The fan is moved by a standard A/C motor, which means inverting the power flow won't damage it but it will make it spin the opposite way. As the configuration from the outside is: external grid, fan, radiator, engine having the fan spinning that way will make it collect any hot air that is around the radiator and push it out, but will also prevent any fresh one coming from outside from reaching the radiator itself.

Only a note: if you do end up opening the box that contains the connections, remember to re-seal it properly by pushing the two pins that keep it closed all the way back into their sockets. It's vital for that box to remain as protected from water as possible, as any liquid in it could favour oxidation and damage the connectors or the board.